From swody1 at goshenarc.org Fri Dec 1 00:53:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 19:53:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010055 SWODY1 SPC AC 010053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 PM CST THU NOV 30 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE SERN U.S. THROUGH THE TN VALLEY INTO SRN PARTS OF THE OH VALLEY... ...KY THROUGH TN VALLEY AND PORTIONS OF THE SERN STATES... ARCTIC FRONT EXTENDS FROM THE LOWER GREAT LAKES SWWD THROUGH OH TO A SURFACE LOW NEAR MEMPHIS. THE FRONT THEN EXTENDS SWD THROUGH WRN MS AND SERN LA. THE LOW WILL DEEPEN FURTHER AND LIFT NEWD TONIGHT AS ASCENT WITHIN DIVERGENT EXIT REGION OF CYCLONICALLY CURVED UPPER JET OVERTAKES THE FRONT. AS THIS OCCURS...THE PORTION OF FRONT S OF THE LOW WILL SHIFT MORE RAPIDLY EWD THROUGH THE TN VALLEY AND SERN STATES. AS THE LOW DEEPENS...THE LOW LEVEL JET AND FRONTOGENETIC FORCING WILL INCREASE THIS EVENING...ESPECIALLY OVER THE TN VALLEY INTO KY. PRE-FRONTAL WARM SECTOR IS CHARACTERIZED BY BOUNDARY LAYER DEWPOINTS FROM THE UPPER 60S NEAR THE COAST TO NEAR 60 IN SRN PARTS OF THE OH VALLEY. HOWEVER...POOR MID LEVEL LAPSE RATES AND LIMITED DAYTIME HEATING HAVE RESULTED IN VERY WEAK INSTABILITY WITH MUCAPE GENERALLY FROM 100 TO 300 J/KG. THE 00Z JAN SOUNDING SHOWS ONLY A SLIVER OF CAPE IN THE 700-500 MB LAYER. A PRE-FRONTAL CONVECTIVE BAND EXTENDS FROM MIDDLE TN SWD THROUGH SERN MS. FARTHER W A MORE STRONGLY FORCED BAND EXTENDS ALONG THE FRONT FROM EXTREME WRN TN SWD THROUGH WRN MS. STRONG LINEAR FORCING MAY CONTINUE TO SUPPORT A LINE OF LOW TOPPED CONVECTION WITH LITTLE LIGHTNING ALONG THE FRONT AS IT MOVES EWD THROUGH THE EVENING AND OVERNIGHT. STRENGTHENING LOW LEVEL WIND PROFILES WITH 60+ KT JUST OFF THE SURFACE WILL EXIST IN VICINITY OF THIS CONVECTION...AND SOME OF THIS MOMENTUM COULD BE TRANSPORTED DOWN TO THE SURFACE WITHIN THE HEAVIER SHOWERS...PROMOTING A THREAT FOR ISOLATED DAMAGING WIND. LARGE LOW LEVEL HODOGRAPHS AND STRONG CLOUD LAYER SHEAR WOULD ALSO LEND SOME SUPPORT FOR LOW TOPPED SUPERCELLS. HOWEVER...THE WEAK INSTABILITY WILL CONTINUE TO SERVE AS AN OVERALL LIMITING FACTOR FOR A MORE ROBUST SEVERE THREAT. ..DIAL.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 05:48:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 00:48:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010550 SWODY1 SPC AC 010548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST THU NOV 30 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS FOR PORTIONS OF MD...PA AND NY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NC THROUGH THE MID ATLANTIC...NERN U.S. AND ERN PORTIONS OF THE OH VALLEY... ...SYNOPSIS... SHORTWAVE TROUGH OVER THE LOWER MS VALLEY THIS EVENING WILL EJECT NEWD INTO THE LOWER GREAT LAKES AND NERN U.S. BY FRIDAY AFTERNOON. ATTENDANT SURFACE CYCLONE CURRENTLY OVER WRN KY WILL OCCLUDE AS IT LIFTS NWD INTO THE GREAT LAKES BY LATE MORNING. HOWEVER...SECONDARY CYCLOGENESIS IS EXPECTED FARTHER EAST ACROSS NY AS STRONG FORCING FOR ASCENT WITHIN DIVERGENT EXIT REGION OF CYCLONIC UPPER JET LIFTS NEWD INTO THIS REGION. ARCTIC FRONT CURRENTLY EXTENDS FROM THE UPPER GREAT LAKES AREA SWWD TO A SURFACE LOW NEAR WRN KY THEN SWD INTO THE CNTRL GULF AREA. NRN PORTION OF THIS BOUNDARY WILL MOVE LITTLE DUE TO ACCELERATING SLY FLOW IN WARM SECTOR ACCOMPANYING CYCLOGENESIS. HOWEVER...SRN PORTION OF THIS BOUNDARY WILL CONTINUE EAST THROUGH THE SERN STATES...MID ATLANTIC AND NERN U.S. BEFORE MOVING OFFSHORE FRIDAY NIGHT. ...MID ATLANTIC THROUGH NERN STATES AND ERN PORTION OF OH VALLEY... LOW LEVEL JET WILL STRENGTHEN TO IN EXCESS OF 70 KT FROM NC INTO THE NERN U.S. AS SECONDARY CYCLONE DEEPENS OVER NY. LOW TO MID 60S BOUNDARY LAYER DEWPOINTS CURRENTLY RESIDE ACROSS VA AND THE CAROLINAS. THE STRENGTHENING SLY LOW LEVEL JET WILL CONTRIBUTE TO NWD ADVECTION OF THIS MOISTURE THROUGH FRIDAY. AS UPPER TROUGH EJECTS NEGATIVELY TILTED INTO THE NERN STATES...A MID LEVEL THERMAL TROUGH WILL SPREAD OVER A PORTION OF THE WARM SECTOR AND CONTRIBUTE TO SLIGHTLY BETTER MID LEVEL LAPSE RATES THAN IN THURSDAYS WARM SECTOR. PRE-FRONTAL MUCAPE AROUND 500 J/KG WILL BE POSSIBLE...ESPECIALLY IF POCKETS OF HEATING CAN DEVELOP. INSTABILITY COULD BE SLIGHTLY HIGHER WITHIN ZONE OF FORCED DEEP LAYER ASCENT ALONG SURFACE FRONT. CONVECTION WILL LIKELY BE ONGOING ALONG THE FRONT OVER PORTIONS OF THE OH VALLEY EARLY FRIDAY. STRENGTHENING LOW-MID LEVEL WIND FIELDS AND INCREASING ISALLOBARIC AND FRONTOGENETIC FORCING SHOULD MAINTAIN A FORCED LINE OF STORMS EWD THROUGH THE NERN STATES. THIS ACTIVITY WILL LIKELY STRENGTHEN AS THE ATMOSPHERE UNDERGOES FURTHER DESTABILIZATION DURING THE AFTERNOON. LOW LEVEL AND CLOUD LAYER SHEAR PROFILES WITH LARGE HODOGRAPHS WILL SUPPORT ORGANIZED STORMS INCLUDING LEWP/BOWS WITHIN THE LINE. A FEW SUPERCELL STRUCTURES WILL ALSO BE POSSIBLE ALONG THE LINE OR IF STORMS MANAGE TO DEVELOP AHEAD OF THE LINE. WITH THE LOW LEVEL JET STRENGTHENING TO 60+ KT JUST OFF THE SURFACE...POTENTIAL WILL EXIST FOR THIS MOMENTUM TO BE TRANSPORTED DOWN TO THE SURFACE AS FRONTAL CONVECTION SPREADS EWD. PRIMARY THREAT WILL BE DAMAGING WIND...BUT AN ISOLATED TORNADO OR TWO MAY ALSO BE POSSIBLE. GREATEST THREAT FOR SWATHS OF WIDESPREAD DAMAGING WIND IS EXPECTED IN MODERATE RISK AREA WITH MORE ISOLATED WIND POTENTIAL IN SLIGHT RISK REGION. ...NC... STRONGEST FORCING WILL LIFT N OF THIS REGION. THIS ALONG WITH MODEST LAPSE RATES AND INSTABILITY MAY SERVE TO LIMIT OVERALL SEVERE THREAT. HOWEVER...GIVEN STRENGTH OF LOW LEVEL WIND FIELDS...WILL MAINTAIN A THREAT FOR ISOLATED WIND DAMAGING WITH ANY CONVECTION DEVELOPING ALONG OR JUST AHEAD OF THE FRONT. ..DIAL.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 12:59:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 07:59:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011301 SWODY1 SPC AC 011259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST FRI DEC 01 2006 VALID 011300Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE MID ATLANTIC STATES AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM NC AND ERN OH INTO CNTRL NEW ENGLAND... ...SYNOPSIS... INTENSE SHORTWAVE TROUGH NOW OVER IL/IND EXPECTED TO CONTINUE ACCELERATING NEWD TODAY/TONIGHT AS IT ASSUMES AN INCREASINGLY NEGATIVE TILT. THE SYSTEM SHOULD BE CENTERED E OF TORONTO BY THIS EVENING AS ASSOCIATED SFC LOW MOVES RAPIDLY ENE FROM WRN OH TO N OF KALB. COLD FRONT TRAILING SSW FROM LOW SHOULD REACH THE NJ CST AND ERN NC BY 00Z SATURDAY. THE FRONT LIKELY WILL BE WELL OFF THE CST BY MIDNIGHT. ...UPR OH VLY/MID ATLANTIC/NERN STATES... LLJ WILL STRENGTHEN TO MORE THAN 70 KTS FROM NC INTO THE NERN U.S. LATER TODAY AS SFC LOW DEEPENS AND TRACKS ENE ACROSS NRN PA/UPSTATE NY. SEASONABLY RICH BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE UPR 50S TO MID 60S/ WILL SWEEP FARTHER NNE INTO THE DELAWARE AND HUDSON VLYS...AND INTO THE SRN HALF OF NEW ENGLAND. ACCELERATION OF NEGATIVE TILT UPR TROUGH WILL ENHANCE LARGE SCALE FORCING FOR ASCENT IN VERY STRONGLY SHEARED ENVIRONMENT ALONG/AHEAD OF SYSTEM COLD FRONT. COUPLED WITH INCREASING MOISTURE AND MODEST DIURNAL HEATING...SETUP MAY SUPPORT DEVELOPMENT AND/OR INTENSIFICATION OF NARROW...FAST-MOVING CONVECTIVE LINES/STORMS. WITH PRE-FRONTAL MUCAPE AROUND 500 J/KG...COMBINATION OF STRONG GRADIENT FLOW WITH CONVECTIVELY-ENHANCED WINDS COULD YIELD SCATTERED SWATHS OF DAMAGING WIND. ISOLATED TORNADOES WILL ALSO BE POSSIBLE...ESPECIALLY INVOF LINE BREAKS...GIVEN INTENSE LOW LEVEL SHEAR /0-1 KM SRH AOA 300 M2/S2/. WIND DAMAGE POTENTIAL SHOULD BE GREATEST ALONG AND JUST S OF MID LEVEL SPEED MAX FROM CNTRL/ERN PA INTO PARTS OF NY/NJ AND WRN/SRN NEW ENGLAND...WITH MORE ISOLATED WIND DAMAGE EXPECTED FARTHER S. ...NC/SRN VA... STRONGEST FORCING WILL LIFT N OF THIS REGION. THIS FACTOR...ALONG WITH MODEST INSTABILITY...SHOULD SERVE TO LIMIT OVERALL SEVERE THREAT. NEVERTHELESS...GIVEN STRENGTH OF LOW LEVEL WIND FIELD...A LOW PROBABILITY WILL EXIST FOR DAMAGING WIND WITH ANY SUSTAINED CONVECTION FORMING ALONG OR JUST AHEAD OF COLD FRONT. ..CORFIDI/KERR.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 16:29:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 11:29:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011631 SWODY1 SPC AC 011629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST FRI DEC 01 2006 VALID 011630Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS INTO PARTS OF THE MID ATLANTIC AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE PIEDMONT INTO THE NORTHEAST... ...PIEDMONT INTO THE MID ATLANTIC AND NORTHEAST... PAIR OF SURFACE LOWS WILL CONTINUE TO DEEPEN AHEAD OF INTENSE MID/UPPER LEVEL LOW NOW SPREADING TOWARDS ONTARIO. LEADING LOW CONTINUES ALONG EFFECTIVE COLD FRONT/WARM FRONT NOW NEAR LAKE ERIE. INTENSE PRESSURE FALLS ARE OCCURRING AHEAD OF THIS LOW...AND MORNING MODELS FORECAST THE LOW TO DEEPEN AND LIFT INTO NERN NY BY THE EARLY EVENING. THIS WILL SURGE LEADING COLD FRONT EWD ACROSS THE APPALACHIANS AND EXTEND FROM ERN NY SSWWD ACROSS WRN NJ AND THE CHESAPEAKE REGION BY 00Z...AND OFF THE COAST BY MIDNIGHT. ACCOMPANYING WARM FRONT...NOW WELL DEFINED ACROSS FAR SWRN NY INTO CENTRAL NEW ENGLAND...WILL LIFT QUICKLY NWD INTO SWRN/CENTRAL NY AND EVENTUALLY ACROSS ALL BUT NRN NEW ENGLAND LATER THIS EVENING. NARROW LINE OF DEEP MOIST CONVECTION HAS STEADILY INCREASED AND BECOME MORE ORGANIZED INTO FAR WRN PA ND NERN WV THIS MORNING. DESPITE THE LIMITED LAPSE RATES AHEAD OF THIS ACTIVITY...INTENSE DEEP ASCENT WILL FORCE A NARROW LINE OF INTENSE CONVECTION/THUNDERSTORMS EWD ACROSS MUCH OF THE CENTRAL APPALACHIANS INTO THE URBAN CORRIDOR FROM PARTS OF CENTRAL/ERN VA INTO THE HUDSON VALLEY/NEW ENGLAND THROUGH THE EARLY EVENING. AS THE AFTERNOON PROGRESSES...CLOUD TO GROUND LIGHTNING WILL LIKELY STEADILY INCREASE...AS WILL THE POTENTIAL FOR DAMAGING WINDS. VWP DATA FROM KCCX AND KPBZ AHEAD OF THE LINE INDICATE EXTREME WINDS /I.E. 50-60 KT SLYS/ JUST OFF THE SURFACE...WITH RESULTANT VERY LARGE HODOGRAPHS. THUS IT APPEARS WIND DAMAGE MAY BECOME QUITE PRONOUNCED/WIDESPREAD INTO THE MID AFTERNOON AND CONTINUE WELL INTO THE EARLY EVENING FROM PORTIONS OF CENTRAL PA/NRN MD INTO SWRN NEW ENGLAND/SERN NY. GIVEN THE MAGNITUDE OF LOW LEVEL SHEAR AND RELATIVELY HIGH BOUNDARY LAYER RH ...ISOLATED TORNADO THREAT WILL ACCOMPANY QUASI-LINEAR OR MORE DISCRETE STORMS. SEVERE THREAT WILL BECOME MORE CONDITIONAL FARTHER SOUTH ALONG THE FRONT /SOUTH OF THE DELMARVA REGION/ DUE TO RELATIVELY WEAKER ASCENT. HOWEVER...VERY IMPRESSIVE LOW LEVEL WIND PROFILES AND VERY WARM/MOIST BOUNDARY LAYER SHOULD SUPPORT A THREAT OF DAMAGING WINDS AND POSSIBLY TORNADOES. ..EVANS/CROSBIE.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 19:50:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 14:50:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011952 SWODY1 SPC AC 011949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST FRI DEC 01 2006 VALID 012000Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS CENTRAL AND EASTERN PA...SOUTH CENTRAL AND SOUTHEASTERN NY AND NORTHWEST NJ... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN MID-ATLANTIC REGION INTO CNTRL/SRN NEW ENGLAND... ...MID-ATLANTIC INTO NY STATE AND CNTRL/SRN NEW ENGLAND... STRONG UPPER LOW CONTINUED TO MOVE NEWD THROUGH THE OH VLY AT MID-AFTN AND SHOULD MOVE INTO SERN CANADA TONIGHT. CYCLOGENESIS CONTINUES ACROSS WRN NY STATE AHEAD OF THE LOW. THIS LOW WILL MOVE INTO SRN QUE THIS EVENING. A WEAKER SUB-SYNOPTIC LOW MAY BE FORMING ACROSS CNTRL PA AS THE SRN AXIS OF LARGE SCALE HEIGHT FALLS SPREADS ACROSS THE APPALACHIANS. THIS FEATURE SHOULD MOVE INTO SCNTRL/SERN NY THIS EVENING AND INTO CNTRL NEW ENGLAND OVERNIGHT. A WARM MOIST BOUNDARY LAYER CONTINUED TO SPREAD NWD THROUGH THE REGION AHEAD OF THE UPPER SYSTEM. WARM FRONT SITUATED FROM THE WRN NY CYCLONE EWD INTO SRN NH WILL LIKELY MOVE A LITTLE FARTHER NWD...BUT IT APPEARS THAT EXTREME NRN SECTIONS OF NY-VT-NH AND MOST OF MAINE SHOULD REMAIN IN THE COLD AIR THE LONGEST...MITIGATING WIDESPREAD SVR WEATHER. FARTHER S...A SEGMENTED COLD FRONT EXISTS FROM SWRN NY ACROSS PA INTO THE CAROLINAS. INITIAL BAND OF TSTMS THAT PRODUCED DAMAGING WINDS ACROSS WRN PA HAD WEAKENED...BUT APPEARS TO BE STRENGTHENING AGAIN EAST OF THE MOUNTAINS. SFC ANALYSIS PLACES A LOW-LEVEL THERMAL RIDGE THROUGH ERN PA INTO SCNTRL NY WHERE TEMPERATURES HAVE CLIMBED TO NEAR 70 DEG F RESULTING IN RUC-DERIVED MLCAPES AROUND 500 J/KG. AS THE STRONGEST LARGE SCALE ASCENT SPREADS ACROSS THE REGION...THE STORMS MAY INTENSIFY AND EVOLVE MORE LINEARLY AS THEY TRANSLATE INTO ERN PA AND SCNTRL-SERN NY WITH BOWS/LEWPS. 55 KT 1KM FLOW WILL LIKELY BE BROUGHT TO THE SFC...AUGMENTING POTENTIAL FOR DAMAGING WINDS. FURTHERMORE...ISOLD TORNADOES WILL BE POSSIBLE... ESPECIALLY WITH ANY EMBEDDED SUPERCELL STRUCTURES THAT DEVELOP. FARTHER N...REMNANT BAND OF CONVECTION WILL LIKELY CONTINUE ACROSS CNTRL NY WITH POTENTIAL FOR MORE ISOLD DAMAGING WINDS. OVERNIGHT...PRIMARY LINE OF TSTMS SHOULD MOVE FROM THE NRN MID ATLANTIC REGION/SERN NY EWD ACROSS CNTRL/SRN NEW ENGLAND. SLY FLOW HAS BROUGHT A MARINE ENVIRONMENT NWD INTO MUCH OF SRN NEW ENGLAND. BUT...THE BOUNDARY LAYER SHOULD REMAIN SUFFICIENTLY TURBULENT TO MAINTAIN A SLGT RISK OF DAMAGING WINDS ACROSS THAT REGION OVERNIGHT. ..RACY.. 12/01/2006  From swody1 at goshenarc.org Sat Dec 2 00:40:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 19:40:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020042 SWODY1 SPC AC 020040 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 PM CST FRI DEC 01 2006 VALID 020100Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS NERN U.S.... ...NERN STATES THROUGH SRN NEW ENGLAND... STRONGLY FORCED SQUALL LINE FROM SRN NH SWD THROUGH NJ AND MD WILL CONTINUE RAPIDLY EWD AND OFFSHORE WITHIN THE NEXT FEW HOURS. WITH 80+ KT JUST OFF THE SURFACE...THREAT FOR DAMAGING WIND GUSTS WILL ACCOMPANY THE STRONGER STORMS WITHIN THE LINE. AS STORMS CONTINUE EAST...THEY WILL ENCOUNTER A BOUNDARY LAYER THAT IS MORE STABLE OVER SRN NEW ENGLAND DUE TO THE INFLUX OF COOLER MARINE AIR. AS A RESULT STORMS MAY BECOME A LITTLE LESS EFFICIENT TRANSPORTING STRONGER WINDS DOWN TO THE SURFACE AND UNDERGO GRADUAL WEAKENING. HOWEVER...AT LEAST ISOLATED DAMAGING WIND POTENTIAL IS EXPECTED TO PERSIST UNTIL ACTIVITY MOVES OFFSHORE. LARGE 0-2 KM HODOGRAPHS WILL CONTINUE TO SUPPORT POTENTIAL FOR LOW LEVEL MESOCYCLONES AND ISOLATED TORNADOES WITH ANY SUPERCELLS EMBEDDED WITHIN THE LINE. HOWEVER...TORNADO POTENTIAL SHOULD ALSO GRADUALLY DECREASE AS THE LINES MOVES EAST INTO A MORE STABLE BOUNDARY LAYER. ..DIAL.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 05:33:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 00:33:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020534 SWODY1 SPC AC 020532 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST FRI DEC 01 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE MODIFYING ARCTIC HIGH PRESSURE WILL PREVAIL OVER MUCH OF THE NATION WITH OFFSHORE FLOW OVER THE GULF. THIS WILL RESULT IN MOSTLY STABLE CONDITIONS AND LIMIT THUNDERSTORM POTENTIAL. SOME CONVECTION WILL BE POSSIBLE WITHIN ZONE OF WEAK ISENTROPIC ASCENT IN VICINITY OF STALLED FRONT ACROSS PARTS OF NRN FL AND SRN GA SATURDAY EVENING. HOWEVER...THE THERMODYNAMIC ENVIRONMENT WITH LIMITED INSTABILITY SUGGESTS ANY LIGHTING ACTIVITY SHOULD REMAIN ISOLATED. ..DIAL.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 12:53:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 07:53:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021255 SWODY1 SPC AC 021253 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 AM CST SAT DEC 02 2006 VALID 021300Z - 031200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD...SLOWLY PROGRESSIVE POSITIVE TILT UPR TROUGH WILL PREVAIL ACROSS THE LWR 48 THIS PERIOD. TWO IMPULSES IN WEAK SPLIT OVER THE WRN STATES AND SW CANADA ARE EXPECTED TO PHASE OVER THE CNTRL/SRN PLNS LATER IN THE PERIOD...LEADING TO SLIGHT RIDGING OVER S FL AND THE WRN ATLANTIC. TRAILING FRONT ASSOCIATED WITH SYSTEM THAT EXITED THE NERN U.S. LATE YESTERDAY SHOULD BECOME STATIONARY OVER CNTRL FL LATER TODAY/ TONIGHT. WEAK WARM ADVECTION WILL DEVELOP N OF THIS BOUNDARY ACROSS N FL/GA AND SC EARLY SUNDAY AS PHASING TROUGH AMPLIFIES OVER THE PLNS. WARM LAYER BETWEEN 700 AND 500 MB SUGGESTS THAT ANY ASSOCIATED CONVECTIVE DEVELOPMENT WILL REMAIN TOO SHALLOW FOR CHARGE SEPARATION/THUNDER. ISOLATED STORMS MAY...HOWEVER...OCCUR THROUGHOUT THE PERIOD OVER THE OFFSHORE WATERS INVOF THE FRONT... FROM OFF THE NC/SC CST SW INTO THE GULF OF MEXICO. IN THE NRN STREAM...A LIGHTNING STRIKE OR TWO MAY OCCUR THIS EVENING NEAR THE KEWEENAW PENINSULA OF MI AS VERY COLD AIR ALOFT AND WEAK LOW LEVEL CONVERGENCE FIELD ACCOMPANY SLOW MOVING UPR VORT NOW OVER NRN MN. ..CORFIDI/PETERS.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 15:56:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 10:56:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021557 SWODY1 SPC AC 021555 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0955 AM CST SAT DEC 02 2006 VALID 021630Z - 031200Z ...NO TSTM AREAS FORECAST... AIR MASS WILL REMAIN TOO STABLE FOR DEEP MOIST CONVECTION TODAY ACROSS THE CONUS. SHALLOW MOIST CONVECTION SHOULD OCCUR NEAR STALLED SURFACE FRONT ACROSS NRN FL AND IN THE LEE OF THE GREAT LAKES...PARTICULARLY INTO THE KEWEENAW PEN OF UPPER MI. HOWEVER...LIGHTNING POTENTIAL APPEARS QUITE LOW IN THESE AREAS. ..EVANS.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 19:39:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 14:39:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021941 SWODY1 SPC AC 021939 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0139 PM CST SAT DEC 02 2006 VALID 022000Z - 031200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... CP AIR MASS COVERING MOST OF THE CONUS WILL PRECLUDE DEEP MOIST CONVECTION THROUGH TONIGHT. SHALLOW MOIST CONVECTION COULD OCCUR VCNTY A STALLED FRONT ACROSS NRN FL AND POSSIBLY IN THE LEE OF THE GRTLKS. LIGHTNING POTENTIAL...HOWEVER...WILL REMAIN QUITE LOW IN THESE AREAS /LESS THAN 10 PERCENT/. ..RACY/EVANS.. 12/02/2006  From swody1 at goshenarc.org Sun Dec 3 00:54:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 19:54:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030056 SWODY1 SPC AC 030054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0654 PM CST SAT DEC 02 2006 VALID 030100Z - 031200Z ...NO TSTM AREAS FORECAST... A BROAD CNTRL AND ERN U.S. UPPER-LEVEL TROUGH WILL REMAIN IN PLACE TONIGHT AS COLD SFC HIGH PRESSURE MOVES SWD INTO THE PLAINS STATES. THIS WILL REINFORCE NLY FLOW ACROSS THE CONUS WITH LOW-LEVEL MOISTURE MAINLY CONFINED TO THE FL PENINSULA. HOWEVER...LARGE-SCALE ASCENT SHOULD BE INSUFFICIENT ACROSS FL FOR THE DEVELOPMENT OF THUNDERSTORM ACTIVITY TONIGHT. ..BROYLES.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 05:22:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 00:22:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030524 SWODY1 SPC AC 030522 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 PM CST SAT DEC 02 2006 VALID 031200Z - 041200Z ...NO SVR TSTM AREAS FORECAST... A BROAD UPPER-LEVEL TROUGH OVER THE PLAINS STATES WILL DIG SEWD INTO THE MS VALLEY SUNDAY. AT THE SFC...A LOW AND WARM FRONT OFF THE COAST OF THE CAROLINAS WILL MOVE TOWARD THE COAST DURING THE DAY. THUNDERSTORM ACTIVITY ALONG THE WARM FRONT WILL BECOME INCREASINGLY LIKELY BY EVENING DUE TO STRENGTHENING LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY AND A DEVELOPING LOW-LEVEL JET. A FEW THUNDERSTORMS MAY AFFECT PAMLICO SOUND AND THE CAPE HATTERAS NATIONAL SEASHORE BY SUNDAY EVENING. HOWEVER...INSTABILITY IS FORECAST TO REMAIN WEAK AND NO SEVERE THREAT IS ANTICIPATED SUNDAY. ..BROYLES.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 12:51:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 07:51:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031252 SWODY1 SPC AC 031250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 AM CST SUN DEC 03 2006 VALID 031300Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD...POSITIVE TILT TROUGH WILL CONTINUE TO MOVE SLOWLY E ACROSS THE CNTRL AND ERN U.S. THIS PERIOD AS E PACIFIC RIDGE REACHES THE W CST/GRT BASIN. PHASING OF SHORTWAVE IMPULSES NOW OVER THE SRN RCKYS AND UPR MS VLY WILL RESULT IN FURTHER AMPLIFICATION OF TROUGH OVER THE SRN PLNS. THIS IN TURN WILL LEAD TO SFC DEVELOPMENT LATER TODAY/TONIGHT ALONG FRONT STALLED OFF THE SC/NC CST. THE WAVE SHOULD ACCELERATE ENE INTO THE ATLANTIC TO A POSITION WELL OFF THE MARYLAND CST BY 12Z MONDAY. STRENGTHENING 925-850 MB WARM ADVECTION N OF SFC FRONT MAY YIELD SUFFICIENT ELEVATED INSTABILITY TO ALLOW ASSOCIATED CONVECTION/ POSSIBLE THUNDER TO GRAZE THE OUTER BANKS REGION OF NC THIS EVENING/EARLY TONIGHT. FAST EWD MOTION OF SFC WAVE AND LIMITED DEGREE OF MOISTURE/BUOYANCY IN ELEVATED UNSTABLE LAYER SUGGEST THAT COVERAGE OVER LAND SHOULD REMAIN LIMITED. ELSEWHERE...DESTABILIZATION OF FAIRLY SHALLOW /BELOW 700 MB/ MIXED LAYER MAY SUPPORT DEEPENING OF CONVECTION OVER THE UPR GRT LKS LATER TODAY/TONIGHT. OVERALL COOLNESS OF SOUNDINGS AND LIMITED CONVECTIVE DEPTHS SUGGEST THAT ANY THUNDER WILL REMAIN ISOLATED. ..CORFIDI.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 16:23:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 11:23:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031625 SWODY1 SPC AC 031622 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1022 AM CST SUN DEC 03 2006 VALID 031630Z - 041200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD...POSITIVE TILT TROUGH WILL CONTINUE TO MOVE SLOWLY E ACROSS THE CNTRL AND ERN U.S. THIS PERIOD AS E PACIFIC RIDGE REACHES THE W CST/GRT BASIN. PHASING OF SHORTWAVE IMPULSES NOW OVER THE SRN RCKYS AND UPR MS VLY WILL RESULT IN FURTHER AMPLIFICATION OF TROUGH OVER THE SRN PLNS. THIS IN TURN WILL LEAD TO SFC DEVELOPMENT LATER TODAY/TONIGHT ALONG FRONT STALLED OFF THE SC/NC CST. THE WAVE SHOULD ACCELERATE ENE INTO THE ATLANTIC TO A POSITION WELL OFF THE MARYLAND CST BY 12Z MONDAY. STRENGTHENING 925-850 MB WARM ADVECTION N OF SFC FRONT MAY YIELD SUFFICIENT ELEVATED INSTABILITY TO ALLOW ASSOCIATED CONVECTION/POSSIBLE THUNDER TO DEVELOP JUST OFF THE NC COAST THIS EVENING/EARLY TONIGHT. FAST EWD MOTION OF SFC WAVE AND LIMITED DEGREE OF MOISTURE/BUOYANCY IN ELEVATED UNSTABLE LAYER SUGGEST THAT COVERAGE OVER LAND SHOULD REMAIN LIMITED. ..EVANS/CORFIDI.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 19:25:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 14:25:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031927 SWODY1 SPC AC 031925 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0125 PM CST SUN DEC 03 2006 VALID 032000Z - 041200Z ...NO TSTM AREAS FORECAST... UPPER TROUGH WILL AMPLIFY TONIGHT AS IT MOVES ACROSS THE ERN STATES. WEAK CYCLOGENESIS WAS OCCURRING OFF THE CAROLINA COAST ALONG AN OLD FRONT. THIS LOW WILL TRACK OFF THE MID-ATLANTIC COAST LATER TONIGHT. MID-LEVEL FRONTOGENESIS WILL INCREASE WITHIN NWRN PARTS OF THE DEVELOPING CYCLONE ACROSS THE OUTER BANKS OF NC TONIGHT RESULTING IN AN INCREASE IN CONVECTION. ISOLD LIGHTNING WILL BE POSSIBLE AS WEAK ELEVATED UPRIGHT AND SLANTWISE CAPE DEVELOP COINCIDENT WITH THE DEFORMATION BAND. COVERAGE OVER LAND AREAS WILL LIKELY BE LESS THAN 10 PERCENT WITH HIGHER TSTM PROBABILITIES IN THE OFFSHORE WATERS. ..RACY.. 12/03/2006  From swody1 at goshenarc.org Mon Dec 4 00:45:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 19:45:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040047 SWODY1 SPC AC 040045 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 PM CST SUN DEC 03 2006 VALID 040100Z - 041200Z ...NO TSTM AREAS FORECAST... A LARGE MS VALLEY UPPER-LEVEL TROUGH WILL MOVE EWD REACHING THE APPALACHIAN MTNS LATE TONIGHT. AT THE SFC...COLD HIGH PRESSURE WILL SETTLE INTO THE SCNTRL UNITED STATES. THIS WILL RESULT IN NLY FLOW ACROSS MUCH OF THE SRN PLAINS AND SERN U.S. WHICH WILL LIMIT LOW-LEVEL MOISTURE EXCEPT ACROSS THE FL PENINSULA. A SFC LOW CURRENTLY EXISTS OFF THE COAST OF WILMINGTON NC AND THIS FEATURE WILL MOVE NWD TO NEAR CAPE HATTERAS TONIGHT. STRONG LOW-LEVEL CONVERGENCE NEAR THE SFC LOW MAY ALLOW THUNDERSTORMS TO INITIATE LATE THIS EVENING. HOWEVER...MOST OF THE LIGHTNING WITH THE CONVECTION SHOULD REMAIN OFFSHORE. ..BROYLES.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 05:16:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 00:16:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040517 SWODY1 SPC AC 040515 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 PM CST SUN DEC 03 2006 VALID 041200Z - 051200Z ...NO TSTM AREAS FORECAST... NORTHWEST FLOW WILL BE IN PLACE MONDAY ACROSS MOST OF THE CONUS AS AN UPPER-LEVEL TROUGH BROADENS AND MOVES ACROSS THE ERN SEABOARD. AT THE SFC...HIGH PRESSURE WILL DOMINATE ACROSS THE SRN U.S. AS ANOTHER COLD FRONT MOVES SWD ACROSS THE NCNTRL U.S. AS A RESULT...NLY FLOW WILL IMPEDE MOISTURE RETURN FROM THE GULF OF MEXICO AND THUNDERSTORMS ARE NOT EXPECTED ACROSS THE CONUS MONDAY OR MONDAY NIGHT. ..BROYLES.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 12:24:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 07:24:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041225 SWODY1 SPC AC 041222 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0622 AM CST MON DEC 04 2006 VALID 041300Z - 051200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD LONG WAVE TROUGH WILL PERSIST OVER THE ERN HALF OF NOAM THIS PERIOD AS LOW AMPLITUDE RIDGE CONTINUES ALONG THE CA CST. SFC WAVE NOW WELL OFF THE MD/DE CST SHOULD FURTHER DEEPEN AS IT CONTINUES RAPIDLY NEWD LATER TODAY AND TUESDAY. FARTHER W...NEXT SIGNIFICANT IMPULSE IN PERSISTENT WNWLY JET IS OVER MN/WI. THIS FEATURE SHOULD REACH PA/NY BY 12Z TUESDAY...WITH MINIMAL ADDITIONAL DEVELOPMENT. ISOLATED TSTMS LIKELY WILL PERSIST INVOF ACCELERATING SFC WAVE/COLD FRONT OVER THE N ATLANTIC CSTL WATERS FOR A FEW MORE HOURS THIS MORNING. LATER IN THE PERIOD...CONVECTION MAY DEEPEN AND YIELD A LIGHTNING STRIKE OR TWO OVER ERN LK HURON AS BOUNDARY LAYER DESTABILIZES IN WAKE OF PASSING UPR DISTURBANCE. ..CORFIDI.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 15:57:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 10:57:38 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041558 SWODY1 SPC AC 041556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0956 AM CST MON DEC 04 2006 VALID 041630Z - 051200Z ...NO TSTM AREAS FORECAST... ..EVANS.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 20:00:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 15:00:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042001 SWODY1 SPC AC 041958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST MON DEC 04 2006 VALID 042000Z - 051200Z ...NO TSTM AREAS FORECAST... NO ORGANIZED AREAS OF THUNDERSTORM ACTIVITY ARE ANTICIPATED TODAY. ..HART.. 12/04/2006  From swody1 at goshenarc.org Tue Dec 5 00:39:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 19:39:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050041 SWODY1 SPC AC 050038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0638 PM CST MON DEC 04 2006 VALID 050100Z - 051200Z ...NO TSTM AREAS FORECAST... NORTHWEST FLOW WILL REMAIN IN PLACE ACROSS THE CONUS TONIGHT. AT THE SFC...HIGH PRESSURE WILL DOMINATE IN THE PLAINS AND SERN UNITED STATES KEEPING LOW-LEVEL MOISTURE AT BAY IN THE GULF OF MEXICO. FOR THIS REASON...THUNDERSTORM ACTIVITY IS NOT EXPECTED ACROSS THE CONUS TONIGHT. ..BROYLES.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 05:02:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 00:02:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050504 SWODY1 SPC AC 050502 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1102 PM CST MON DEC 04 2006 VALID 051200Z - 061200Z ...NO TSTM AREAS FORECAST... A BROAD UPPER-TROUGH WILL MOVE OFF THE ERN SEABOARD THIS MORNING AS ANOTHER SHORTWAVE TROUGH DIGS SEWD INTO THE NRN PLAINS TODAY. AT THE SFC...HIGH PRESSURE WILL DOMINATE THE ERN HALF OF THE NATION WITH ANOTHER COLD FRONT MOVING SWD INTO THE PLAINS STATES AND UPPER MIDWEST. ALTHOUGH SLY FLOW WILL RETURN TO THE SRN PLAINS AND MS VALLEY...SIGNIFICANT LOW-LEVEL MOISTURE RETURN WILL BE DELAYED. AS A RESULT...THUNDERSTORMS ARE NOT EXPECTED ACROSS THE CONUS TUESDAY AND TUESDAY NIGHT. ..BROYLES.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 12:21:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 07:21:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051223 SWODY1 SPC AC 051221 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0621 AM CST TUE DEC 05 2006 VALID 051300Z - 061200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD LONG WAVE TROUGH WILL PERSIST OVER THE ERN TWO THIRDS OF NOAM THIS PERIOD. ONE LOW AMPLITUDE SHORTWAVE DISTURBANCE NOW OVER THE UPR OH VLY WILL EXIT THE NERN STATES LATER TODAY AS UPSTREAM IMPULSE OVER SRN SASKATCHEWAN DROPS SE/ESE ACROSS THE UPR MS VLY/UPR GRT LKS. SFC RIDGING OVER THE GULF OF MEXICO AND DRY LOW LEVEL ENVIRONMENT WILL CONTINUE TO PROHIBIT DEEP CONVECTIVE DEVELOPMENT ACROSS THE NATION THIS PERIOD. MODERATE LAKE-ENHANCED CONVECTIVE BANDS/ CLUSTERS NOW PRESENT E OF LKS ERIE AND ONTARIO SHOULD DIMINISH LATER TODAY AS BOUNDARY LAYER BECOMES MORE SHALLOW IN WAKE OF PASSING UPR TROUGH. ..CORFIDI.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 16:10:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 11:10:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051611 SWODY1 SPC AC 051608 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1008 AM CST TUE DEC 05 2006 VALID 051630Z - 061200Z ...NO TSTM AREAS FORECAST... ..SYNOPSIS/FORECAST... BROAD LONG WAVE TROUGH WILL PERSIST OVER THE ERN TWO THIRDS OF NOAM THIS PERIOD. ONE LOW AMPLITUDE SHORTWAVE DISTURBANCE NOW OVER THE UPR OH VLY WILL EXIT THE NERN STATES LATER TODAY AS UPSTREAM IMPULSE OVER SRN SASKATCHEWAN DROPS SE/ESE ACROSS THE UPR MS VLY/UPR GRT LKS. SFC RIDGING OVER THE GULF OF MEXICO AND DRY LOW LEVEL ENVIRONMENT WILL CONTINUE TO PROHIBIT DEEP CONVECTIVE DEVELOPMENT ACROSS THE NATION THIS PERIOD. MODERATE LAKE-ENHANCED CONVECTIVE BANDS/CLUSTERS NOW PRESENT E OF LKS ERIE AND ONTARIO SHOULD DIMINISH LATER TODAY AS BOUNDARY LAYER BECOMES MORE SHALLOW IN WAKE OF PASSING UPR TROUGH. ..EVANS/CORFIDI.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 19:23:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 14:23:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051924 SWODY1 SPC AC 051922 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0122 PM CST TUE DEC 05 2006 VALID 052000Z - 061200Z ...NO TSTM AREAS FORECAST... ..DARROW.. 12/05/2006  From swody1 at goshenarc.org Wed Dec 6 00:57:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 19:57:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060058 SWODY1 SPC AC 060056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST TUE DEC 05 2006 VALID 060100Z - 061200Z ...NO SVR TSTM AREAS FORECAST... A LARGE LOW-AMPLITUDE UPPER-LEVEL TROUGH WILL BE IN PLACE ACROSS THE CNTRL AND ERN U.S. TONIGHT. AT THE SFC...A TROUGH WILL MOVE SEWD ACROSS THE PLAINS STATES AS A SFC HIGH MOVES OFF THE ERN SEABOARD. LOW-LEVEL MOISTURE WILL REMAIN CONFINED TO THE SRN FL PENINSULA. HOWEVER...A LACK OF LARGE-SCALE ASCENT SHOULD KEEP ANY CONVECTION VERY ISOLATED. ELSEWHERE...THUNDERSTORM ACTIVITY IS NOT EXPECTED ACROSS THE CONUS. ..BROYLES.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 05:58:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 00:58:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060600 SWODY1 SPC AC 060557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST TUE DEC 05 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... A BROAD POSITIVELY TILTED UPPER-LEVEL TROUGH WILL AMPLIFY AS A DISTURBANCE MOVES QUICKLY SWD OUT OF CANADA TODAY AND TONIGHT. IN RESPONSE...A COLD FRONT WILL DIVE SWD ACROSS THE PLAINS AND UPPER MIDWEST. ISOLATED CONVECTION MAY DEVELOP THIS EVENING OVER LAKE SUPERIOR DUE TO WARM LAKE WATERS AND COLD AIR ALOFT WITH THE UPPER-TROUGH. IN ADDITION...THUNDERSTORMS WILL BE POSSIBLE OFF THE COAST OF THE ERN SEABOARD AS A SUBTLE LEAD SHORTWAVE TROUGH EJECTS OUT AHEAD OF THE LARGER GREAT LAKES TROUGH. NO THUNDERSTORM ACTIVITY IS EXPECTED TO REACH SEVERE LIMITS TODAY OR TONIGHT. ..BROYLES.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 12:57:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 07:57:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061258 SWODY1 SPC AC 061256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 AM CST WED DEC 06 2006 VALID 061300Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... THE LAST IN A SERIES OF SHORT WAVE DISTURBANCES REINFORCING LONG WAVE TROUGH OVER ERN NOAM WILL AMPLIFY AS IT DROPS SSE FROM SASKATCHEWAN/MANITOBA INTO WI/MI BY 12Z THURSDAY...WHILE PROGRESSIVE W CST RIDGE REACHES THE GRT BASIN/CANADIAN RCKYS. AT LOWER LEVELS...HIGH PRESSURE WILL EXPAND RAPIDLY SWD INTO THE N CNTRL STATES IN WAKE OF AMPLIFYING UPR TROUGH. AHEAD OF ASSOCIATED PRESSURE SURGE/COLD FRONT...A WEAKER COLD FRONT WILL SETTLE SE INTO E TX AND THE NWRN GULF...AND E/SE TOWARD THE ERN SEABOARD. DRY LOW LEVEL CONDITIONS AND SUBSIDENCE INVERSIONS WILL LIMIT DEPTH OF CONVECTIVE DEVELOPMENT OVER MOST OF THE LWR 48. SHOWERS AND POSSIBLE EMBEDDED TSTMS COULD...HOWEVER...DEVELOP LATE IN THE PERIOD JUST OFF THE MIDDLE TX GULF CST...WHERE UPLIFT ALONG WEAK FRONT MAY BE ENHANCED BY JET ENTRANCE REGION ASCENT ASSOCIATED WITH AMPLIFYING NRN STREAM IMPULSE. SCTD TSTMS MAY ALSO FORM LATE IN THE PERIOD OFF THE NC CST...WHERE LOW LEVEL CONVERGENCE/MOISTURE INFLOW WILL INCREASE AHEAD OF APPROACHING COLD FRONT. OVER THE GRT LKS...MID LEVEL COLD ADVECTION COUPLED WITH FAVORABLE OVER-LAKE FETCHES MAY RESULT IN CONVECTION SUFFICIENTLY DEEP/SUSTAINED TO YIELD A FEW LIGHTNING STRIKES DURING THE LAST HALF OF THE PERIOD OVER LKS SUPERIOR AND MICHIGAN. ..CORFIDI.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 15:51:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 10:51:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061552 SWODY1 SPC AC 061551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0951 AM CST WED DEC 06 2006 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... TESTING. THE 1630Z OUTLOOK WILL BE ISSUED SHORTLY. TESTING. ..AFWA.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 16:27:52 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 11:27:52 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061629 SWODY1 SPC AC 061627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST WED DEC 06 2006 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER GREAT LAKES... APPEARS MOST LIKELY AREA FOR CHARGE SEPARATION WITHIN MOIST CONVECTION WILL OCCUR OVER LAKE SUPERIOR AND POSSIBLY ERN LAKE MI LATER TONIGHT. VERY COLD UPPER LOW WILL SHIFT RAPIDLY SEWD ACROSS THE REGION THROUGH LATTER HALF OF THE PERIOD...WITH ACCOMPANYING -20C TO -24C H85 TEMPERATURES OVERSPREADING THE UPPER LAKES IN WAKE OF SURFACE COLD FRONT. GIVEN CURRENT LAKE SST AROUND 4C TO 7C... VERY STEEP LOW LEVEL LAPSE RATES WILL DEVELOP BENEATH INVERSION LAYER AROUND 750 MB. FORECAST SOUNDINGS SUPPORT SOME LIGHTNING POTENTIAL WITH STRENGTHENING LAKE EFFECT SNOW BANDS INTO UPPER MI LATER TODAY AND INTO PORTIONS OF WRN MI LATE TONIGHT. ...ELSEWHERE... MOIST CONVECTION WILL NOT LIKELY BECOME ROBUST ENOUGH FOR LIGHTNING ACTIVITY OVER SRN FL AND FAR ERN NC THIS PERIOD...AS MOST ACTIVITY REMAINS OFFSHORE. ..EVANS.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 19:48:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 14:48:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061950 SWODY1 SPC AC 061948 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0148 PM CST WED DEC 06 2006 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER GREAT LAKES... STRONG COLD ADVECTION THROUGH THE LOWER TROPOSPHERE WILL STEEPEN LAPSE RATES SIGNIFICANTLY OVER LAKE SUPERIOR THIS AFTERNOON/EVENING...WITH STRONG COOLING EXPECTED LATER OVER THE REMAINDER OF LAKE MI. CONVECTION WILL GRADUALLY DEVELOP/EXPAND ACROSS LAKE SUPERIOR INTO THE EVENING HOURS AND ISOLATED LIGHTING MAY DEVELOP WITH HEAVIER SNOW BANDS...ESPECIALLY AFTER DARK. ..DARROW.. 12/06/2006  From swody1 at goshenarc.org Thu Dec 7 00:35:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 19:35:30 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070036 SWODY1 SPC AC 070034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST WED DEC 06 2006 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WESTERN GREAT LAKES... ARCTIC COLD FRONT HAS MOVED THROUGH THE U.P AND WI AND WILL SWEEP SEWD ACROSS THE REMAINDER OF THE GREAT LAKES REGION OVERNIGHT. STRONG COLD ADVECTION THROUGHOUT THE LOWER TROPOSPHERE WAS STEEPENING LOW LEVEL LAPSE RATES OVER LAKE SUPERIOR...WITH THESE STEEPER LAPSE RATES EXPECTED TO EXPAND SEWD INTO THE WRN PORTIONS OF LOWER MI BETWEEN 06-12Z. THIS WILL RESULT IN LAKE EFFECT CONVECTION TO GRADUALLY DEEPEN WITH TIME AND INCREASE THE THREAT FOR LIGHTNING...ESPECIALLY AFTER 06Z. ..IMY.. 12/07/2006  From swody1 at goshenarc.org Thu Dec 7 19:26:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 14:26:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071927 SWODY1 SPC AC 071926 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0126 PM CST THU DEC 07 2006 VALID 072000Z - 081200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... MERIDIONAL PATTERN EXISTS ACROSS THE COUNTRY WITH A DEEP TROUGH IN THE EASTERN CONUS AND A RIDGE IN THE WEST. THE EASTERN TROUGH IS FORCING A STRONG SURFACE COLD FRONT THROUGH MOST OF THE COUNTRY EAST OF THE ROCKIES...LEADING TO A COLD AND STABLE BOUNDARY LAYER IN MOST AREAS. ADDITIONALLY...SHORTWAVE ENERGY IS UNDERCUTTING THE RIDGE IN NORTHERN MEXICO WHERE A CLOSED UPPER LOW IS EXPECTED TO FORM LATER TODAY. ...GREAT LAKES... VERY COLD AIR AT ALL LEVELS IS OVERSPREADING THE GREAT LAKES WHERE WATER TEMPERATURES ARE GENERALLY FROM 2 TO 8 DEGREES C...LEADING TO INSTABILITY AND CONVECTIVE SNOW BANDS IN LOCATIONS WHERE THE SURFACE FETCH IS DOWNSTREAM FROM THE LAKE. THE CORE OF THE COLDEST AIR IS ADVECTING OVER TOP LAKE ERIE...AND SOME ISOLATED LIGHTNING IS POSSIBLE OVER THE LAKE AND ON THE SOUTHERN SHORES GIVEN EXPECTED MIXED PHASE CLOUD CONTENT AND CAPES AROUND 250 J/KG. HOWEVER...WITH NORTHWESTERLY SURFACE FLOW THE FETCHES WILL BE LIMITED AND GIVEN THAT NO LIGHTNING HAS BEEN OBSERVED THUS FAR...COVERAGE IS EXPECTED TO BE LESS THAN 10 PERCENT. ...FLORIDA... THE COLD FRONT IS PUSHING SLOWLY SOUTHWARD THROUGH FLORIDA GENERATING SOME SHOWER ACTIVITY. INSTABILITY IS LACKING EXCEPT IN EXTREME SOUTHERN FLORIDA...WHERE FORCING AND MID LEVEL LAPSE RATES ARE WEAK DESPITE AMPLE LOW LEVEL MOISTURE...AND EVEN THAT IS SLOWLY DECREASING AS DRIER AIR FILTERS IN FROM THE NORTH. ISOLATED LIGHTNING IS POSSIBLE IF LOCAL BOUNDARY INTERACTIONS CAN GENERATE ENOUGH FORCING FOR DEEP CONVECTION...BUT WIDESPREAD COVERAGE IS NOT EXPECTED. ...SOUTHERN TEXAS... SHOWER ACTIVITY IS ONGOING ALONG THE FRONT ENHANCED BY THE RIGHT REAR QUADRANT OF A JET STREAK AT THE BASE OF THE TROUGH. SOUNDINGS INDICATE A MOIST ADIABATIC ATMOSPHERE AND LIMITED INSTABILITY...PRECLUDING LIGHTNING. A SHORTWAVE IN THE SUBTROPICAL JET STREAM WILL BEGIN TO IMPACT THE REGION BUT NOT BEFORE THE COLD FRONT HAS CLEARED THE AREA...LEADING TO STABLE CONDITIONS. ..AFWA.. 12/07/2006  From swody1 at goshenarc.org Thu Dec 7 19:46:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 14:46:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071947 SWODY1 SPC AC 071926 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0126 PM CST THU DEC 07 2006 VALID 072000Z - 081200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... MERIDIONAL PATTERN EXISTS ACROSS THE COUNTRY WITH A DEEP TROUGH IN THE EASTERN CONUS AND A RIDGE IN THE WEST. THE EASTERN TROUGH IS FORCING A STRONG SURFACE COLD FRONT THROUGH MOST OF THE COUNTRY EAST OF THE ROCKIES...LEADING TO A COLD AND STABLE BOUNDARY LAYER IN MOST AREAS. ADDITIONALLY...SHORTWAVE ENERGY IS UNDERCUTTING THE RIDGE IN NORTHERN MEXICO WHERE A CLOSED UPPER LOW IS EXPECTED TO FORM LATER TODAY. ...GREAT LAKES... VERY COLD AIR AT ALL LEVELS IS OVERSPREADING THE GREAT LAKES WHERE WATER TEMPERATURES ARE GENERALLY FROM 2 TO 8 DEGREES C...LEADING TO INSTABILITY AND CONVECTIVE SNOW BANDS IN LOCATIONS WHERE THE SURFACE FETCH IS DOWNSTREAM FROM THE LAKE. THE CORE OF THE COLDEST AIR IS ADVECTING OVER TOP LAKE ERIE...AND SOME ISOLATED LIGHTNING IS POSSIBLE OVER THE LAKE AND ON THE SOUTHERN SHORES GIVEN EXPECTED MIXED PHASE CLOUD CONTENT AND CAPES AROUND 250 J/KG. HOWEVER...WITH NORTHWESTERLY SURFACE FLOW THE FETCHES WILL BE LIMITED AND GIVEN THAT NO LIGHTNING HAS BEEN OBSERVED THUS FAR...COVERAGE IS EXPECTED TO BE LESS THAN 10 PERCENT. ...FLORIDA... THE COLD FRONT IS PUSHING SLOWLY SOUTHWARD THROUGH FLORIDA GENERATING SOME SHOWER ACTIVITY. INSTABILITY IS LACKING EXCEPT IN EXTREME SOUTHERN FLORIDA...WHERE FORCING AND MID LEVEL LAPSE RATES ARE WEAK DESPITE AMPLE LOW LEVEL MOISTURE...AND EVEN THAT IS SLOWLY DECREASING AS DRIER AIR FILTERS IN FROM THE NORTH. ISOLATED LIGHTNING IS POSSIBLE IF LOCAL BOUNDARY INTERACTIONS CAN GENERATE ENOUGH FORCING FOR DEEP CONVECTION...BUT WIDESPREAD COVERAGE IS NOT EXPECTED. ...SOUTHERN TEXAS... SHOWER ACTIVITY IS ONGOING ALONG THE FRONT ENHANCED BY THE RIGHT REAR QUADRANT OF A JET STREAK AT THE BASE OF THE TROUGH. SOUNDINGS INDICATE A MOIST ADIABATIC ATMOSPHERE AND LIMITED INSTABILITY...PRECLUDING LIGHTNING. A SHORTWAVE IN THE SUBTROPICAL JET STREAM WILL BEGIN TO IMPACT THE REGION BUT NOT BEFORE THE COLD FRONT HAS CLEARED THE AREA...LEADING TO STABLE CONDITIONS. ..AFWA.. 12/07/2006  From swody1 at goshenarc.org Fri Dec 8 00:38:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 19:38:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080039 SWODY1 SPC AC 080036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0636 PM CST THU DEC 07 2006 VALID 080100Z - 081200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SURFACE HIGH PRESSURE...COVERING MOST THE NATION...IS RESULTING IN AN ENVIRONMENT GENERALLY TOO STABLE FOR THUNDERSTORMS. THOUGH WEAK CONVECTION WAS NOTED WITHIN LAKE EFFECT SNOWBANDS... THIS VERY LOW TOPPED CONVECTION SHOULD GRADUALLY DIMINISH AS COLD UPPER TROUGH SHIFTS EAST OF THE REGION. ELEVATED WEAK CONVECTION WAS ALSO LOCATED ACROSS THE NRN FL PENINSULA..BEHIND SURFACE FRONT. WIDESPREAD PRECIPITATION WAS LOCATED ACROSS SRN TX...AHEAD OF A SHORTWAVE TROUGH IN MEXICO. LIMITED INSTABILITY SHOULD LIMIT VERTICAL CLOUD DEPTH AND LIGHTNING ACROSS BOTH OF THESE AREAS. ..IMY.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 04:47:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 23:47:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080448 SWODY1 SPC AC 080446 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1046 PM CST THU DEC 07 2006 VALID 081200Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... DEEP AND COLD UPPER TROUGH IN THE NORTHEAST WILL MOVE OFFSHORE FRIDAY AFTERNOON...AS A WEAKER TROUGH MOVES ONSHORE ALONG THE PACIFIC COAST. BETWEEN THESE TWO SYSTEMS...A RIDGE ALOFT SHOULD RESULT IN THE COUNTRY TO BE THUNDER FREE. THE ONLY EXCEPTION MIGHT BE NEAR THE CA COAST...AS COLD AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH...SPREADS INLAND. HOWEVER...THE LACK OF INSTABILITY AND MOIST ADIABATIC PROFILES SUGGEST THE THREAT FOR MORE THAN A LIGHTNING STRIKE OR TWO IS TOO LOW TO WARRANT A THUNDER OUTLOOK. ..IMY.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 12:49:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 07:49:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081250 SWODY1 SPC AC 081248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0648 AM CST FRI DEC 08 2006 VALID 081300Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... SOME EWD PROGRESSION OF THE DEEP ERN STATES MID LEVEL TROUGH AND THE RIDGE OVER THE ROCKIES IS EXPECTED THROUGH TOMORROW AS THE FIRST IN A SERIES OF SHORTWAVE TROUGHS APPROACHES THE CA COAST. THUNDERSTORMS ARE NOT EXPECTED ACROSS THE MAJORITY OF THE CONUS AS A RESULT OF STRONG SURFACE RIDGING AND OFFSHORE FLOW ACROSS THE GULF AND ATLANTIC COASTS. THE TROUGH NEAR 130 W WILL REACH CA THIS EVENING...THOUGH THE WAVE SHOULD LOSE SOME AMPLITUDE IS IT ENCROACHES ON THE BROAD RIDGE OVER THE INTERMOUNTAIN WEST. A COUPLE OF LIGHTNING STRIKES HAVE BEEN NOTED IN OCEANIC LIGHTNING DATA...BUT WEAKENING OF THIS SYSTEM WITH TIME SUGGESTS THAT ANY THUNDERSTORM THREAT SHOULD DIMINISH BEFORE REACHING THE CA COAST. OTHERWISE...ANY WEAK MID LEVEL INSTABILITY ASSOCIATED WITH THE LOW OVER NW MEXICO SHOULD REMAIN S OF THE RIO GRANDE. ..THOMPSON.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 16:03:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 11:03:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081602 SWODY1 SPC AC 081559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0959 AM CST FRI DEC 08 2006 VALID 081630Z - 091200Z ...NO TSTM AREAS FORECAST... UPPER RIDGE CURRENTLY OVER THE WESTERN UNITED STATES IS EXPECTED TO MOVE EASTWARD TODAY...ALLOWING HIGH-AMPLITUDE TROUGH OFF THE PACIFIC COAST TO MOVE INLAND. COLD TEMPERATURES ALOFT MAY RESULT IN ISOLATED LIGHTNING STRIKES OFF THE CA COAST TODAY. HOWEVER...THREAT FOR THUNDERSTORMS OVER THE MAINLAND APPEARS LOW. ELSEWHERE...NO ORGANIZED THUNDERSTORM ACTIVITY IS FORECAST TODAY. ..HART.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 19:15:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 14:15:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081916 SWODY1 SPC AC 081913 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0113 PM CST FRI DEC 08 2006 VALID 082000Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... AN UPPER RIDGE WILL CONTINUE TO SHIFT SLOWLY EWD ACROSS THE CENTRAL CONUS THROUGH THE REMAINDER OF THIS PERIOD...WHILE ONE SHORT-WAVE TROUGH MOVES ONSHORE ACROSS THE WEST AND A SECOND CONTINUES TO DEPART THE EAST. WITH ANY APPRECIABLE LIGHTNING ACTIVITY THIS PERIOD FORECAST TO REMAIN OFFSHORE AS STABLE AIRMASS PREVAILS ACROSS THE CONUS...WILL MAINTAIN FORECAST FOR LESS THAN 10% THUNDERSTORM COVERAGE. ..GOSS.. 12/08/2006  From swody1 at goshenarc.org Sat Dec 9 00:44:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 19:44:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090045 SWODY1 SPC AC 090043 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0643 PM CST FRI DEC 08 2006 VALID 090100Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... SURFACE RIDGE AT THE SURFACE AND ALOFT COVERS A MAJORITY OF THE NATION...RESULTING IN GENERALLY STABLE AND DRY CONDITIONS. THE EXCEPTION INCLUDED PRECIPITATION IN SRN TX AND THE PACIFIC COAST AS SHORTWAVE TROUGHS APPROACHED BOTH REGIONS. HOWEVER...LIMITED INSTABILITY SHOULD PRECLUDE A LIGHTNING THREAT ACROSS BOTH AREAS. ..IMY.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 04:44:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 23:44:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090445 SWODY1 SPC AC 090441 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1041 PM CST FRI DEC 08 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ..SYNOPSIS... SHORTWAVE TROUGH...CURRENTLY LOCATED ABOUT 800 MILES WEST OF SFO...IS MOVING EWD AT 35 KT AND THIS MOTION WOULD BRING THE SYSTEM INTO CA SATURDAY NIGHT. THOUGH INSTABILITY IS FORECAST TO REMAIN MARGINAL...MUCAPES AOB 350 J/KG...STRONG FORCING AND MID LEVEL LAPSE RATES NEAR 7C/KM SHOULD SUPPORT CONVECTION WITH SOME LIGHTNING BETWEEN 21-06Z. THUNDERSTORMS ARE EXPECTED BE MOST NUMEROUS OFFSHORE AND ALONG THE COAST...WHERE THE INSTABILITY WILL BE THE GREATEST. ELSEWHERE...LARGE SURFACE HIGH PRESSURE AND ASSOCIATED STABLE AIRMASS WILL INHIBIT CONVECTION ACROSS THE REMAINDER OF THE CONUS. ..IMY.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 13:00:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 08:00:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091301 SWODY1 SPC AC 091259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST SAT DEC 09 2006 VALID 091300Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE LARGE SCALE PATTERN IS BECOMING MORE ZONAL/PROGRESSIVE WITH TIME...THOUGH A RELATIVELY COLD/DRY CONTINENTAL AIR MASS IN THE LOW LEVELS WILL INHIBIT DEEP CONVECTION OVER THE MAJORITY OF THE CONUS. A WEAKENING SRN STREAM WAVE OVER NE MEXICO WILL MOVE OVER S TX...BUT THUNDERSTORMS ARE NOT EXPECTED GIVEN ONLY MINIMAL MID LEVEL INSTABILITY IN ASSOCIATION WITH THIS WAVE. A MORE SUBSTANTIAL THREAT FOR AT LEAST ISOLATED THUNDERSTORMS IS EXPECTED ACROSS THE NRN/CENTRAL CA COAST AND CENTRAL VALLEYS AS A SHORTWAVE TROUGH CURRENTLY LOCATED NEAR 35 N AND 130 W MOVES EWD TO THE CA COAST BY 00Z. SATELLITE IMAGERY AND OCEANIC LIGHTNING DATA SHOW EMBEDDED CONVECTION AND ISOLATED THUNDERSTORMS WITHIN THE INITIAL BAROCLINIC BAND AND NEAR THE COLD CORE. THESE AREAS OF CONVECTION WILL LIKELY PERSIST AND SPREAD INLAND THIS EVENING INTO TONIGHT ..THOMPSON.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 16:19:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 11:19:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091620 SWODY1 SPC AC 091618 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1018 AM CST SAT DEC 09 2006 VALID 091630Z - 101200Z ...NO SVR TSTM AREAS FORECAST... SATELLITE IMAGERY AND MODEL GUIDANCE SHOW NEXT IN A SERIES OF STRONG SHORTWAVE TROUGHS APPROACHING THE PACIFIC COAST. THIS FEATURE IS FORECAST TO MOVE ASHORE TONIGHT...PROVIDING STRONG ASCENT AND WIDESPREAD PRECIPITATION TO NORTHERN/CENTRAL CA AND PARTS OF SOUTHERN ORE. COLD TEMPERATURES ALOFT AND RELATIVELY STEEP MID LEVEL LAPSE RATES ARE EXPECTED TO RESULT IN POCKETS OF MARGINAL INSTABILITY OVERNIGHT. COMBINATION OF LARGE SCALE FORCING FOR ASCENT AND OROGRAPHIC FORCING WILL AID IN THE THREAT OF ISOLATED THUNDERSTORMS ACROSS THE REGION. NO SEVERE THUNDERSTORMS ARE ANTICIPATED. ELSEWHERE ACROSS THE NATION...RELATIVELY DRY/STABLE CONDITIONS ARE EXPECTED TO PRECLUDE THUNDERSTORM ACTIVITY. ..HART.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 19:47:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 14:47:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091948 SWODY1 SPC AC 091946 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0146 PM CST SAT DEC 09 2006 VALID 092000Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AS AN UPPER SHORT-WAVE TROUGH MOVES EWD ACROSS THE ROCKIES AND EVENTUALLY INTO THE PLAINS WITHIN LARGER-SCALE UPPER RIDGE...A SECOND/STRONGER TROUGH WILL MOVE ONSHORE OVER THE WRN CONUS THROUGH THE SECOND HALF OF THE PERIOD. THE AIRMASS OVER THE CONUS FROM THE ROCKIES EWD SHOULD REMAIN UNSUPPORTIVE OF DEEP MOIST CONVECTION. HOWEVER...A FEW ONSHORE LIGHTNING STRIKES MAY OCCUR OVER PARTS OF NRN AND CENTRAL CA DURING THE SECOND HALF OF THE PERIOD...AS POSSIBLE AREAS OF MINIMAL INSTABILITY DEVELOP -- PARTICULARLY ALONG THE CA COAST. ..GOSS.. 12/09/2006  From swody1 at goshenarc.org Sun Dec 10 00:54:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 19:54:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100054 SWODY1 SPC AC 100052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 PM CST SAT DEC 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/NRN CA... FRONTAL BAND CONTINUES TO SPREAD ONSHORE NRN/CNTRL CA THIS EVE WITH EMBEDDED TSTMS. 00Z OAK SOUNDING STILL INDICATES A WARM LAYER JUST ABOVE 660 MB. THIS SUGGESTS THAT PRIMARY TSTM PROBABILITIES WITH THE FRONTAL BAND WILL MAINLY BE NORTH OF THE BAY AREA/CNTRL CA THIS EVE. BUT...AS PRIMARY COLD CORE ASSOCD WITH THE UPPER WAVE MOVES INLAND...POTENTIAL INSTABILITY/TSTM PROBABILITIES WILL SPREAD INLAND AND SWD WITH TIME PER LATEST RUC/NAM CROSS-SECTIONS. ..RACY.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 05:21:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 00:21:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100522 SWODY1 SPC AC 100519 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 PM CST SAT DEC 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL CA... THE MID-LEVEL SHORTWAVE TROUGH MOVING ASHORE CNTRL/NRN CA EARLY SUNDAY MORNING WILL QUICKLY TRANSLATE EWD INTO THE INTERMOUNTAIN WEST BY MID-DAY. H5 TEMPERATURES IN THE MID-MINUS 20S ATOP A PLUME OF MODEST PRECIPITABLE WATER VALUES MAY BE SUFFICIENT FOR EARLY DAY TSTMS IN THE BAY AREA AND PARTS OF THE CNTRL VLY. THE TSTM PROBABILITY WILL DECREASE DURING THE AFTN AS WARMING ALOFT/REBOUNDING HEIGHTS OCCUR IN WAKE OF THE WAVE. ...GREAT BASIN/FOUR CORNERS REGION... THE MID-LEVEL WAVE MOVING INTO CNTRL/NRN CA WILL ARRIVE ACROSS THE GREAT BASIN AND FOUR-CORNERS REGION BY SUNDAY AFTN. STEEPENING MID-TROPOSPHERIC LAPSE RATES AND MODEST LARGE SCALE ASCENT MAY BE SUFFICIENT FOR ISOLD LIGHTNING STRIKES FROM CNTRL/SRN UT AND NRN AZ EWD INTO SWRN CO...PRIMARILY BETWEEN 15-03Z. ..RACY.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 12:54:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 07:54:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101254 SWODY1 SPC AC 101252 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 AM CST SUN DEC 10 2006 VALID 101300Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE MID LEVEL SHORTWAVE TROUGH NOW MOVING FROM CENTRAL CA INTO NV WILL CONTINUE EWD OVER THE FOUR CORNERS BY THIS EVENING...REACHING THE HIGH PLAINS EARLY MONDAY. THE APPROACHING WAVE WILL INDUCE LEE CYCLOGENESIS ACROSS ERN CO AND SLY LOW-LEVEL FLOW ACROSS THE SRN PLAINS. A FEW SHALLOW CONVECTIVE SHOWERS ARE EXPECTED ACROSS SE TX WITHIN A MOISTENING WAA REGIME. HOWEVER...LOW-LEVEL TRAJECTORIES AND MID LEVEL LAPSE RATES DO NOT SUPPORT SUFFICIENT DESTABILIZATION FOR THUNDERSTORMS THIS PERIOD. ...CENTRAL CA TODAY AND THE FOUR CORNERS THIS AFTERNOON... ISOLATED LIGHTNING STRIKES HAVE BEEN NOTED IN NLDN DATA ACROSS CENTRAL CA WITH THE INITIAL SHORTWAVE TROUGH. THIS THREAT SHOULD DIMINISH THIS MORNING AS THE WAVE MOVES E OF THE SIERRA NEVADA...THOUGH ADDITIONAL LOW-TOPPED CONVECTION MAY OCCUR THE FIRST HALF OF THE DAY AS A SECOND SHORTWAVE TROUGH MOVES INLAND. THERE WILL ALSO BE SOME THREAT FOR ISOLATED THUNDERSTORMS THIS AFTERNOON INVOF THE FOUR CORNERS WHERE DAYTIME HEATING...ASCENT/COOLING MID LEVEL TEMPERATURES...AND GRADUAL MOISTENING IN ADVANCE OF THE MID LEVEL WAVE SHOULD RESULT IN THE DEVELOPMENT OF WEAK INSTABILITY. ..THOMPSON.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 15:52:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 10:52:54 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101553 SWODY1 SPC AC 101551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0951 AM CST SUN DEC 10 2006 VALID 101630Z - 111200Z ...NO SVR TSTM AREAS FORECAST... STRONG...FAST MOVING UPPER TROUGH CONTINUES TO TRACK EASTWARD ACROSS THE WESTERN STATES THIS MORNING. THE INITIAL VORT LOBE HAS PASSED OVER THE SIERRAS...WITH LARGE SCALE FORCING FOR ASCENT NOW SPREADING EASTWARD ACROSS THE GREAT BASIN. STEEP LAPSE RATES...SUSTAINED LIFT...AND STRONG DAYTIME HEATING ARE EXPECTED TO RESULT IN A MARGINALLY UNSTABLE AIR MASS THIS AFTERNOON AND EVENING FROM SOUTHERN UT/NORTHERN AZ INTO WESTERN CO. ISOLATED LIGHTNING STRIKES MAY OCCUR ACROSS THIS AREA. ELSEWHERE...A GENERALLY DRY AND STABLE AIRMASS IS EXPECTED TO PRECLUDE THUNDERSTORM ACTIVITY. ..HART.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 19:16:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 14:16:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101917 SWODY1 SPC AC 101914 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0114 PM CST SUN DEC 10 2006 VALID 102000Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHOWERS AND ISOLATED THUNDERSTORMS NOW OVER SRN UT/NRN AZ ARE FORECAST TO CONTINUE/SPREAD EWD ACROSS THE FOUR CORNERS REGION THROUGH THE END OF THE PERIOD...AS COLD AIR ALOFT ASSOCIATED WITH UPPER TROUGH TRAVERSING THE AREA IS YIELDING SUFFICIENT INSTABILITY FOR DEEP MOIST CONVECTION. ELSEWHERE...LACK OF CAPE SHOULD PRECLUDE THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD. ..GOSS.. 12/10/2006  From swody1 at goshenarc.org Mon Dec 11 00:44:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 19:44:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110045 SWODY1 SPC AC 110042 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 PM CST SUN DEC 10 2006 VALID 110100Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...FOUR CORNERS REGION... WATER VAPOR IMAGERY CLEARLY SHOWS THE MID-LEVEL SHORTWAVE TROUGH MIGRATING ACROSS THE SWRN DESERTS THIS EVENING. STRONGEST H5-H3 Q-VECTOR CONVERGENCE IS EXPECTED TO MOVE ACROSS THE SRN ROCKIES AND ONTO THE SRN PLAINS LATER TONIGHT. 00Z FGZ/ABQ/GJT OBSERVED AND RUC FORECAST SOUNDINGS SUGGEST THAT THE THERMODYNAMIC ENVIRONMENT WILL BE MARGINALLY SUPPORTIVE FOR ISOLD TSTMS WEST OF THE DIVIDE ACROSS THE FOUR CORNERS REGION THROUGH ABOUT 06Z. FARTHER E...A DRIER AIR MASS WILL LIMIT THE TSTM THREAT DESPITE THE INCREASE IN LARGE SCALE ASCENT. ..RACY.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 05:39:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 00:39:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110540 SWODY1 SPC AC 110537 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 PM CST SUN DEC 10 2006 VALID 111200Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID-MO/MS VLY/MIDWEST SWD TO THE WRN GULF COAST REGION... UPPER TROUGH OVER THE FOUR CORNERS REGION EARLY ON MONDAY WILL AMPLIFY THROUGH THE DAY WITH 120 METER HEIGHT FALLS SPREADING ACROSS THE SRN PLAINS TO THE UPPER MS VLY BY EARLY TUE. AT THE SFC...PRIMARY SFC LOW WILL EVOLVE AND MOVE ENEWD THROUGH KS TO IA BY LATE MON NIGHT. TRAILING THE LOW...A COLD FRONT/DRY LINE WILL MIGRATE EWD THROUGH THE CNTRL/SRN PLAINS. MODEST RETURN FLOW WILL CONTINUE ACROSS THE CNTRL/SRN PLAINS AND MS VLY MON/MON NIGHT IN ADVANCE OF THE UPPER SYSTEM. 00Z MON RAOBS...HOWEVER...SUGGEST THAT LAPSE RATES WILL REMAIN RATHER POOR UNTIL THE UPPER SYSTEM BEGINS TO TRANSLATE EWD. AS A RESULT...DEVELOPING WARM CONVEYOR/SHOWERS FROM ERN TX NWD INTO THE MIDWEST WILL LIKELY BE UNDERPRODUCTIVE WITH RESPECT TO LIGHTNING THROUGH THE DAYLIGHT HOURS. HIGHER TSTM PROBABILITIES WILL DEVELOP DURING THE NIGHT AS STEEPER MID-LEVEL LAPSE RATES ASSOCD WITH THE APPROACHING SYSTEM SPREAD ENEWD. SPORADIC LIGHTNING MAY OCCUR WITH EVOLVING CONVECTIVE BANDS DEVELOPING N-W OF THE PRIMARY SFC LOW BETWEEN 00-03Z ACROSS THE MID-MO VLY. THIS ACTIVITY WILL EVENTUALLY SPREAD NEWD TOWARD PARTS OF IA AND NRN IL OVERNIGHT. A SEPARATE REGION OF HIGHER TSTM PROBABILITIES WILL EXIST GENERALLY AFT 03-06Z FROM ERN TX NEWD INTO THE MIDWEST ALONG THE ADVANCING COLD FRONT. STRONGER STORMS ARE EXPECTED ACROSS THE LWR MS VLY AS ENHANCED ASCENT ASSOCD WITH A SECONDARY JET STREAK ARRIVES OVERNIGHT COINCIDENT WITH IMPROVING LAPSE RATES. ORGANIZED SEVERE TSTMS ARE NOT ANTICIPATED...HOWEVER. ..RACY.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 13:00:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 08:00:07 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111300 SWODY1 SPC AC 111258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 AM CST MON DEC 11 2006 VALID 111300Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...IA SWD TO LA THIS EVENING AND OVERNIGHT... A MID LEVEL SHORTWAVE TROUGH OVER THE CENTRAL/SRN HIGH PLAINS THIS MORNING WILL MOVE EWD OVER NE/KS/OK/N TX TODAY AND REACH IA/MO/AR/NW LA LATE IN THE PERIOD. AT THE SURFACE...AN ASSOCIATED LEE CYCLONE IN WRN KS WILL DEVELOP EWD ACROSS KS DURING THE DAY...AND THEN NEWD ACROSS NW MO INTO CENTRAL IA EARLY TUESDAY. LOW-LEVEL SLY FLOW IN ADVANCE OF THIS SYSTEM IS DRAWING A MODIFYING GULF AIR MASS NWD...WITH BOUNDARY LAYER DEWPOINTS IN THE LOWER 50S INTO ERN OK AND LOWER 60S ALONG THE UPPER TX COAST. THIS PLUME OF MOISTURE WILL SPREAD NEWD ACROSS LA/AR/MO LATER TODAY INTO TONIGHT. REGIONAL SOUNDINGS...HOWEVER...SUGGEST THAT THE STEEPER L0W-MID LEVEL LAPSE RATES ARE CONFINED TO THE MID LEVEL THERMAL TROUGH OVER THE HIGH PLAINS...AND THE GREATER POTENTIAL FOR DESTABILIZATION WILL BE DELAYED UNTIL THIS EVENING WHEN THESE LAPSE RATES OVERSPREAD THE NW PORTION OF THE LOW-LEVEL MOISTURE PLUME FROM NE KS INTO MO/IA. FARTHER S IN THE WARM SECTOR...GREATER BOUNDARY LAYER MOISTURE/VERTICAL SHEAR WILL BE COUNTERED BY POOR MID LEVEL LAPSE RATES. DESTABILIZATION SHOULD BE SUFFICIENT FOR DEEP CONVECTION BY THIS EVENING AND CONTINUING INTO THE OVERNIGHT HOURS. THE THREAT FOR LIGHTNING WILL GRADUALLY INCREASE BY EARLY TONIGHT WITHIN THE BAND OF SHOWERS FROM SE TX INTO AR AS THE MID LEVELS COOL AND CONVECTIVE CLOUD DEPTH DEEPENS. FARTHER N/NW...SOME SMALL HAIL MAY OCCUR IN CONJUNCTION WITH THE COLDEST MID LEVEL TEMPERATURES AND STEEPEST LAPSE RATES OVER NE KS/NRN MO/SRN IA. HOWEVER...THE THREAT FOR SEVERE STORMS WILL BE MINIMAL GIVEN THE VERY MARGINAL INSTABILITY. ..THOMPSON.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 16:21:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 11:21:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111622 SWODY1 SPC AC 111619 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1019 AM CST MON DEC 11 2006 VALID 111630Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MISSISSIPPI VALLEY... MORNING WATER VAPOR LOOPS SHOW THAT DEEP UPPER TROUGH HAS BECOME ESTABLISHED OVER THE SOUTH-CENTRAL UNITED STATES...WITH SERIES OF TRAILING SHORTWAVE TROUGHS MOVING ONTO THE PACIFIC COAST. RATHER STRONG SOUTH-SOUTHWESTERLY LOW LEVEL WINDS EXTEND FROM TX/LA INTO THE MIDWEST. THIS IS PROVIDING RATHER STRONG LOW LEVEL THERMAL/ MOISTURE ADVECTION AND SCATTERED PRECIPITATION. SHOWER ACTIVITY IS EXPECTED TO PERSIST AND SPREAD EASTWARD THROUGH THE DAY. HOWEVER... GENERAL LACK OF SUFFICIENT INSTABILITY WILL LIKELY PRECLUDE MORE THAN ISOLATED LIGHTNING STRIKES WITHIN CONVECTIVE ACTIVITY. GREATER THREAT OF THUNDERSTORMS MAY DEVELOP LATER TONIGHT ACROSS PARTS OF MO/IL/IA AND POSSIBLY NORTHERN AR AS PLUME OF STEEPER MID LEVEL LAPSE RATES OVERSPREADS REGION. CAPE VALUES WILL REMAIN QUITE LOW. HOWEVER...LARGE SCALE ASCENT AND CONTINUED INFLUX OF LOW LEVEL MOISTURE MAY PROVE SUFFICIENT FOR SCATTERED THUNDERSTORMS CAPABLE OF SMALL HAIL. NO ORGANIZED SEVERE STORMS ARE EXPECTED. ...WA/ORE... SHORTWAVE TROUGH JUST OFF THE WA/ORE/CA COAST WILL MOVE INLAND TODAY. STRONG ONSHORE FLOW AND COLD TEMPERATURES ALOFT WILL POSE A RISK OF ISOLATED THUNDERSTORMS ALONG THE COASTAL RANGES FROM WESTERN WA INTO ORE. ..HART.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 19:35:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 14:35:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111936 SWODY1 SPC AC 111934 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0134 PM CST MON DEC 11 2006 VALID 112000Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...CENTRAL STATES... AMPLIFIED MID/UPPER TROUGH CONTINUES TO PROGRESS EAST OF THE ROCKIES INTO THE PLAINS...WITH A 70+ KT SOUTHWESTERLY 500 MB JET STREAK NOSING ACROSS THE SOUTH CENTRAL PLAINS INTO THE MID/LOWER MISSOURI VALLEY REGION. HOWEVER...LEE SURFACE LOW DEVELOPMENT OVER KANSAS REMAINS WEAK...AND LOW-LEVEL MOISTURE RETURN FROM THE GULF OF MEXICO...STILL MODIFYING IN THE WAKE OF SERIES OF SIGNIFICANT COLD INTRUSIONS...IS JUST UNDERWAY. MID/UPPER 50S SURFACE DEW POINTS HAVE REACHED THE ARKLATEX...AND WILL PROBABLY CONTINUE TO GRADUALLY ADVECT NORTHWARD THROUGH THE OZARKS BY LATE TONIGHT. ELEVATED MOISTURE RETURN IN ZONE OF ISENTROPIC ASCENT TO THE NORTH OF THIS REGION IS ALREADY OCCURRING ...WITH WEAK CONVECTIVE DEVELOPMENT EVIDENT IN RADAR/SATELLITE IMAGERY ACROSS PARTS OF NORTHEAST KANSAS/SOUTHEAST NEBRASKA/ NORTHWEST MISSOURI. HOWEVER...CONVECTION IS STILL CAPPED BY A RELATIVELY WARM 850-700 MB LAYER. THIS MAY REMAIN THE CASE AT LEAST ANOTHER FEW HOURS...BUT CLOSER TO 00Z...AND MORE LIKELY THEREAFTER...IT APPEARS STRONGER MID-LEVEL COOLING/LIFT WILL BE SUFFICIENT FOR AN INCREASE IN THUNDERSTORM ACTIVITY ACROSS THE MID/ LOWER MISSOURI VALLEY. SOME HAIL...POSSIBLY GUSTY WINDS...MAY ACCOMPANY STRONGER CELLS...BUT WITH MOST UNSTABLE CAPE EXPECTED AT OR BELOW 500 J/KG...IT APPEARS MOST STORMS SHOULD REMAIN BELOW SEVERE LIMITS. OTHERWISE...A MORE GRADUAL MID-LEVEL COOLING AND CONTINUED INCREASE IN LOW-LEVEL MOISTURE ARE EXPECTED TO EVENTUALLY SUPPORT A FEW THUNDERSTORMS IN BROADER-SCALE LOW-LEVEL WARM ADVECTION REGIME THROUGH MUCH OF THE MISSISSIPPI VALLEY. THIS MAY NOT OCCUR UNTIL LATE THIS EVENING/OVERNIGHT. ...PACIFIC NORTHWEST... COLDER MID-LEVEL AIR MASS...AND COLDER EQUILIBRIUM TEMPERATURES... ASSOCIATED WITH UPPER TROUGH ARE SPREADING TOWARD NORTHWEST WASHINGTON/VANCOUVER ISLAND...WHERE IT APPEARS BEST POTENTIAL FOR AN ISOLATED THUNDERSTORM OR TWO EXISTS LATE TODAY/TONIGHT. ..KERR.. 12/11/2006  From swody1 at goshenarc.org Tue Dec 12 00:57:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 19:57:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120058 SWODY1 SPC AC 120056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST MON DEC 11 2006 VALID 120100Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID MO/MS VLYS SWD TO NE TX/NRN LA... STRONGER LARGE SCALE ASCENT/STEEP MID-TROPOSPHERIC LAPSE RATES ASSOCD WITH A LEAD MID-LEVEL JETLET WILL CONTINUE TO SPREAD NEWD THROUGH THE MID-MO VLY INTO CNTRL/SRN IA THIS EVE. LATEST ACARS SOUNDING FROM KMCI SAMPLED A WARM NOSE AROUND 810 MB...BUT WITH MODEST LAPSE RATES ABOVE. RUC FORECAST SOUNDINGS SUGGEST THAT LAPSE RATES ALOFT WILL CONTINUE TO STEEPEN WITH TIME AS THE PRIMARY UPPER SYSTEM APPROACHES THE REGION AND MUCAPES COULD REACH AS HIGH AS 500-700 J/KG. THIS WAS ALREADY EVIDENCED BY THE 00Z TOP SOUNDING WHERE H85-H5 LAPSE RATES WERE IN EXCESS OF 8 DEG C PER KM AND MUCAPE OF 557 J/KG. AS A RESULT...SPORADIC TSTMS WILL CONTINUE TO EVOLVE FROM EXTREME SERN NEB AND NERN KS NEWD INTO NWRN MO AND CNTRL/SRN IA THIS EVE WITH SOME TENDENCY TO DEVELOP SWD INTO NRN/CNTRL MO TO THE N OF INTERSTATE 70. GIVEN MAGNITUDE OF LAPSE RATES AND FAVORABLE CAPE-BEARING SHEAR...A FEW OF THE STRONGER STORMS MAY PRODUCE HAIL OR PERHAPS GUSTY WINDS. ELSEWHERE...WARM CONVEYOR BELT CONTINUES TO BE WELL-ESTABLISHED FROM THE WRN GULF COAST NEWD INTO THE MIDWEST THIS EVENING. SRN PERIPHERY OF THE EJECTING UPPER SYSTEM WILL BEGIN TO IMPINGE ON THE WRN PARTS OF THIS CONVEYOR LATER THIS EVENING/OVERNIGHT. 00Z LZK RAOB SUGGEST THAT LAPSE RATES WERE RATHER POOR...BUT AS THE COLDER TEMPERATURES ALOFT SPREAD EWD AND Q-VECTOR CONVERGENCE ARRIVES AFTER 06Z...THERE WILL BE AN INCREASING THREAT FOR TSTMS...ESPECIALLY FROM SERN MO SWD INTO CNTRL AR AND NRN LA. STRONGER STORMS MAY CONTAIN SMALL HAIL...BUT NO ORGANIZED SEVERE TSTMS ARE EXPECTED ALONG SRN PARTS OF THE TSTM OTLK. ..RACY.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 05:33:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 00:33:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120534 SWODY1 SPC AC 120532 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST MON DEC 11 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...LWR OH VLY AND MID-SOUTH... COMPLEX UPPER WAVE LOCATED OVER THE PLAINS EARLY ON TUESDAY WILL TRANSLATE NEWD INTO THE GRTLKS AND THE OH/TN VLYS THROUGH TUESDAY NIGHT. THE INITIAL LEAD WAVE MOVING THROUGH THE CORN BELT EARLY IN THE DAY WILL DAMPEN AS THE CORE OF THE UPPER LOW BEGINS TO ROTATE EWD TOWARD THE UPPER GRTLKS DURING THE AFTN. STRONGER LARGE SCALE HEIGHT FALLS WILL OCCUR FROM THE MID-SOUTH INTO THE LWR OH VLY DURING THE DAY. WARM CONVEYOR CONTINUES TO TRANSPORT MOISTURE NEWD FROM THE GULF OF MEXICO INTO THE MIDWEST...BUT LAPSE RATES ALOFT HAVE REMAINED POOR. H7-H5 LAPSE RATES WILL IMPROVE TUE MORNING AND AS STRONGER Q-VECTOR CONVERGENCE ASSOCD WITH THE MAIN IMPULSE LIFTS NEWD...THE BACK EDGE OF THE SHOWERS MAY INTENSIFY INTO TSTMS. MUCAPES ARE FORECAST TO REACH AROUND 500 J/KG ACROSS PORTIONS OF THE LWR OH VLY/MID-SOUTH FROM LATE TUE MORNING INTO THE AFTN. MAGNITUDE OF MID-LEVEL LAPSE RATES AND FAVORABLE SHEAR IN THE CAPE BEARING LAYER MAY CONTRIBUTE TO ISOLD STRONGER STORMS CAPABLE OF PRODUCING HAIL OR GUSTY WINDS. TSTMS PROBABILITIES WILL DECREASE RAPIDLY AFTER 00Z WED ACROSS THE OH/TN VLYS AS THE UPPER SYSTEM BEGINS TO LIFT NEWD BEYOND THE GULF MOISTURE PLUME. ..RACY.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 12:51:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 07:51:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121252 SWODY1 SPC AC 121250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 AM CST TUE DEC 12 2006 VALID 121300Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...MS/OH VALLEY REGION... WATER VAPOR IMAGERY AND PROFILER DATA SHOW A MID LEVEL SHORTWAVE TROUGH OVER NE TX/SE OK THIS MORNING WHICH WILL ROTATE NEWD TO THE OH VALLEY BY TONIGHT. AN ASSOCIATED SURFACE TROUGH/WEAK COLD FRONT WILL MOVE EWD FROM E TX AND WRN AR TO THE MS RIVER BY THIS EVENING...AND CONTINUE EWD INTO THE TN/OH VALLEYS TONIGHT WHILE BECOMING MORE DIFFUSE. A NARROW CORRIDOR OF MOISTURE RETURN /BOUNDARY LAYER DEWPOINTS OF 56-64 F/ IS PRESENT IN ADVANCE OF THE SURFACE TROUGH AND SW OF THE LARGE RIDGE OVER THE ATLANTIC COAST. THIS MOISTURE WILL SPREAD NEWD TO THE LOWER OH VALLEY AND EWD ACROSS MS/WRN TN DURING THE DAY...BUT THE WARM SECTOR WILL REMAIN NARROW. REGIONAL SOUNDINGS SUGGEST THAT THE STEEPER MID LEVEL LAPSE RATES ARE CONFINED TO THE MID LEVEL THERMAL TROUGH...WHICH IS LARGELY W/NW OF THE RICHER LOW-LEVEL MOISTURE. THIS CONFIGURATION IS AND WILL CONTINUE TO LIMIT THE DEGREE OF INSTABILITY ACROSS THE MS AND LOWER OH VALLEYS TODAY. THE MAJORITY OF THE CONVECTION TODAY WILL REMAIN IN A PRE-FRONTAL BAND...FOCUSED BY LARGE SCALE ASCENT/LOW-LEVEL WAA TO THE E AND NE OF THE SURFACE-BASED INSTABILITY. ASCENT ALONG THE SURFACE TROUGH/WEAK COLD FRONT SHOULD BE RELATIVELY SHALLOW/WEAK...AND THUNDERSTORM DEVELOPMENT SHOULD BE ISOLATED AT BEST ALONG THE SURFACE TROUGH LATER TODAY. IF THUNDERSTORMS DEVELOP...MID LEVEL LAPSE RATES NEAR 7.5 C/KM AND 500 MB TEMPERATURES COLDER THAN -20 C COULD SUPPORT A FEW STORMS WITH MARGINALLY SEVERE HAIL DURING THE AFTERNOON/EARLY EVENING FROM NE AR/WRN TN INTO SRN IL/SW INDIANA. FARTHER S ACROSS LA/MS IN THE MOIST SECTOR...THE SEVERE STORM THREAT WILL BE LIMITED BY POOR MID LEVEL LAPSE RATES AND WEAKENING LOW-LEVEL FLOW/SHEAR DURING THE DAY. ..THOMPSON.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 16:21:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 11:21:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121622 SWODY1 SPC AC 121620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST TUE DEC 12 2006 VALID 121630Z - 131200Z ...NO SVR TSTM AREAS FORECAST... DEEP UPPER TROUGH CONTINUES TO MOVE SLOWLY EASTWARD ACROSS THE CENTRAL UNITED STATES THIS MORNING...WITH PRIMARY SURFACE LOW LIFTING NORTHWARD ACROSS MN. MAIN SURFACE COLD FRONT EXTENDS SOUTHWARD FROM LOW ACROSS CENTRAL MO/AR INTO NORTHEAST TX. NUMEROUS SHOWERS/THUNDERSTORMS HAVE BEEN OCCURRING AHEAD OF FRONT...BUT HAVE NOW MOVED SUFFICIENTLY EASTWARD TO ALLOW BREAKS IN THE CLOUDS ALONG FRONT. WATER VAPOR IMAGERY AND MODEL GUIDANCE SUGGEST THAT STEEP LAPSE RATES AND AT LEAST WEAK LARGE SCALE ASCENT WILL OVERSPREAD THE FRONTAL ZONE THIS AFTERNOON. THIS MAY ALLOW ISOLATED SHOWERS AND THUNDERSTORMS TO RE-DEVELOP ALONG THE FRONT OVER CENTRAL IL...SOUTHEAST MO...INTO EASTERN AR. GIVEN SUFFICIENT DAYTIME HEATING...THE STRONGEST STORMS COULD PRODUCE HAIL AND GUSTY WINDS. ..HART.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 19:55:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 14:55:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121956 SWODY1 SPC AC 121954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0154 PM CST TUE DEC 12 2006 VALID 122000Z - 131200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFIED TROUGH...WITH SEVERAL EMBEDDED SMALLER SCALE IMPULSES... IS ALREADY BEGINNING TO LIFT OUT OF THE MISSISSIPPI VALLEY...AS STRONG HIGH-LEVEL JET NOSES TOWARD THE PACIFIC NORTHWEST. LACK OF SIGNIFICANT SURFACE CYCLOGENESIS AND WEAK RETURN FLOW...OFF A SLOWLY MODIFYING BOUNDARY LAYER OVER THE GULF OF MEXICO... CONTINUES TO MINIMIZE CONVECTIVE POTENTIAL. AND...THIS IS GENERALLY EXPECTED TO REMAIN THE CASE THROUGH THE REMAINDER OF THIS FORECAST PERIOD. ...LOWER MISSISSIPPI VALLEY/CENTRAL GULF COAST... THE MOST SIGNIFICANT ONGOING CONVECTION...INCLUDING SCATTERED THUNDERSTORMS...IS SHIFTING EASTWARD THROUGH THE CENTRAL GULF STATES...IN SOUTHERN PORTION OF ELONGATED ZONE OF LOW-LEVEL WARM ADVECTION/ISENTROPIC ASCENT AHEAD OF UPPER TROUGH AXIS. THIS IS WHERE MOISTURE RETURN HAS BEEN MAXIMIZED ALONG PRE-FRONTAL SOUTHERLY LOW-LEVEL JET AXIS...CONTRIBUTING TO WEAK CAPE. MID-LEVEL LAPSE RATES ARE GENERALLY WEAK...HOWEVER...AND LOW-LEVEL FLOW EAST OF THE LOWER MISSISSIPPI VALLEY IS BEGINNING TO WEAKEN AS 70-90 KT MID-LEVEL JET STREAK LIFTS OUT OF THE LOWER MISSISSIPPI VALLEY INTO THE LOWER OHIO VALLEY. THUNDERSTORM ACTIVITY IS EXPECTED TO DIMINISH ACROSS MISSISSIPPI/ALABAMA LATE THIS AFTERNOON AS LARGE-SCALE ASCENT DECREASES. ...MIDDLE MISSISSIPPI/LOWER OHIO VALLEYS... AN IMPULSE ASSOCIATED WITH THE JET STREAK IS LIFTING NORTHEAST OF THE OZARK PLATEAU. STRONGER FORCING WITH THIS FEATURE IS BEGINNING TO OVERSPREAD NARROW LOW-LEVEL THERMAL RIDGE ACROSS EASTERN MISSOURI INTO SOUTHERN/CENTRAL ILLINOIS...WHERE HEATING OF BOUNDARY LAYER WITH LOWER/MID 50S SURFACE DEW POINTS HAS OCCURRED BENEATH DRY SLOT. MIXED LAYER CAPE OF 250-500 J/KG IS WEAK...BUT LAPSE RATES ARE FAIRLY STEEP...AND CONVECTIVE INSTABILITY PRESENT IN SOUNDINGS WILL PROBABLY BE SUPPORTIVE OF A FEW STORMS WHICH MAY PRODUCE HAIL/WIND GUSTS APPROACHING OR BRIEFLY EXCEED SEVERE LIMITS. A BROKEN LINE OF STORMS APPEARS POSSIBLE ALONG/AHEAD OF THE COLD FRONT LATE THIS AFTERNOON AND EARLY EVENING...BEFORE THE FRONT PROGRESSES THROUGH THE REMAINDER OF THE MORE STRONGLY HEATED BOUNDARY LAYER. THEREAFTER...POTENTIAL WILL DIMINISH DEEPER INTO THE LOWER OHIO VALLEY. ...UPPER MISSISSIPPI VALLEY/GREAT LAKES... PRE-FRONTAL DESTABILIZATION HAS BEEN EVEN WEAKER NORTHWARD INTO PARTS OF THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES. BUT...IT MAY STILL BE SUFFICIENT FOR SCATTERED THUNDERSTORM ACTIVITY... PRIMARILY AS MID-LEVEL TROUGH AXIS SHIFTS ACROSS WISCONSIN LATE THIS AFTERNOON INTO THE EVENING HOURS. AS FORCING CONTINUES EASTWARD ACROSS THE GREAT LAKES OVERNIGHT...COOLER LOW-LEVEL ENVIRONMENT WITH WEAKER LOW-LEVEL LAPSE RATES ARE EXPECTED TO RESULT IN DIMINISHING CONVECTIVE POTENTIAL. ..KERR.. 12/12/2006  From swody1 at goshenarc.org Wed Dec 13 00:48:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 19:48:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130048 SWODY1 SPC AC 130046 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0646 PM CST TUE DEC 12 2006 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...MIDWEST/LWR OH VLY... STRONGER LARGE SCALE ASCENT ASSOCD WITH THE UPPER SHORTWAVE TROUGH WAS SPREADING ENEWD INTO INDIANA AND LWR MI THIS EVENING. THIS WAS SUPPORTING A BAND OF TSTMS ALONG A COLD FRONT THAT WILL MOVE ENEWD ACROSS LWR MI...IND AND KY THROUGH THE NIGHT. BUOYANCY IS LIMITED...BUT 00Z DVN/ILX RAOBS SAMPLED VERY STEEP MID-LEVEL LAPSE RATES WITHIN THE CORE OF THE UPPER SYSTEM. THIS COMBINED WITH MODEST LOW-LEVEL LAPSE RATES FROM THE HEATING CYCLE HAS CONTRIBUTED TO NARROW AXIS OF MUCAPES OF A COUPLE HUNDRED J/KG IMMEDIATELY DOWNSTREAM FROM THE FRONT ACROSS SWRN LWR MI TO WRN KY. TSTMS PROBABILITIES WILL CONTINUE THROUGH THIS EVENING AHEAD OF THE FRONT...BUT EWD EXTENT WILL LIKELY BE MODULATED BY LESS FAVORABLE THERMODYNAMIC PROFILES ACROSS THE MID-UPPER OH VLY. IT APPEARS THAT THE INTENSITY OF STORMS HAS PEAKED AND NO WIDESPREAD SVR WEATHER IS ANTICIPATED. ...CNTRL GULF COASTAL REGION... WATER VAPOR SHOWS A SECONDARY JET STREAK MIGRATING ACROSS THE DEEP S THIS EVE WITH RIGHT-ENTRANCE REGION DERIVED LARGE SCALE UVV SUPPORTING CONVECTION ACROSS AL AND COASTAL MS/LA. BETTER QUALITY BOUNDARY LAYER MOISTURE HUGGING THE COAST VCNTY KMOB APPEARS TO BE SUFFICIENT FOR PARCELS TO REACH INTO THE ICE PRODUCING LAYER FOR LIGHTNING. BUT...00Z JAN/LCH/SHV SOUNDINGS AND LATEST KBTR/KLFT ACARS SUGGEST THAT WARMING IN THE H7-H5 LAYER WILL SPREAD EWD LATER THIS EVENING...MAKING THE ENVIRONMENT INCREASINGLY HOSTILE TO SUSTAINING TSTMS. ..RACY.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 05:34:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 00:34:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130534 SWODY1 SPC AC 130532 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST TUE DEC 12 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... TSTM POTENTIAL WILL REMAIN LOW ACROSS THE COUNTRY ON WED. THE UPPER DISTURBANCE CURRENTLY MOVING THROUGH THE OH VLY WILL BEGIN TO LOOSE AMPLITUDE ON WED AS A MORE POWERFUL NRN STREAM EMERGES ACROSS THE PAC NW TO THE NRN ROCKIES. ISOLD LIGHTNING WILL BE LIKELY ACROSS NWRN WA WHERE A STEEP LAPSE RATES ENVIRONMENT SPREADS EWD TO THE NORTH OF A POWERFUL JET. ELSEWHERE...SRN PERIPHERY OF THE EJECTING OH VLY TROUGH MAY INTERACT WITH MODEST BOUNDARY LAYER MOISTURE SITUATED ALONG THE SERN SEABOARD WED AFTN. TSTM POTENTIAL WILL LIKELY STAY OFFSHORE WHERE STRONGER INSTABILITY WILL RESIDE...BUT ONE OR TWO STRIKES CANNOT BE RULED OUT INVOF THE NC OUTER BANKS. HERE...COVERAGE IS EXPECTED TO REMAIN LESS THAN 10 PERCENT CLOSER TO SHORE. ..RACY.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 13:02:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 08:02:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131303 SWODY1 SPC AC 131301 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0701 AM CST WED DEC 13 2006 VALID 131300Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A LARGELY ZONAL FLOW REGIME IS EXPECTED OVER THE CONUS THROUGH TOMORROW...WITH THE PRIMARY JET FROM THE PAC NW TO THE GREAT LAKES. AN INITIAL MID LEVEL SHORTWAVE TROUGH OVER THE APPALACHIANS THIS MORNING WILL WEAKEN AND MOVE NEWD OVER THE MID ATLANTIC/NEW ENGLAND BY EARLY TONIGHT. THIS MID LEVEL WAVE WILL BE ACCOMPANIED BY A DIFFUSE SURFACE TROUGH/WEAK FRONT WHICH WILL BECOME EVEN LESS DEFINED WITH TIME. MEANWHILE...THE LOW LEVELS HAVE WARMED/MOISTENED ALONG AND SE OF A COASTAL TROUGH OFF GA AND THE CAROLINAS. INITIALLY SHALLOW CONVECTION ALONG THIS TROUGH SHOULD DEEPEN DURING THE DAY...WITH THE THREAT FOR THUNDERSTORMS EXPECTED TO INCREASE JUST OFFSHORE. MORE ISOLATED CONVECTION...AND PERHAPS A FEW LIGHTNING STRIKES...WILL BE POSSIBLE JUST INLAND OF THE SE ATLANTIC COAST THROUGH THIS EVENING. THUNDERSTORM COVERAGE SHOULD REMAIN RATHER SPARSE GIVEN MARGINAL INSTABILITY AND RATHER WEAK FORCING FOR ASCENT. A STRONG TROUGH IS MOVING INLAND OVER WA AND BRITISH COLUMBIA...AND THIS SYSTEM WILL PROGRESS QUICKLY EWD TOWARD THE NRN HIGH PLAINS BY EARLY THURSDAY. RELATIVELY STEEP LAPSE RATES AND COLD MID LEVEL TEMPERATURES COULD SUPPORT ISOLATED THUNDERSTORMS THE FIRST HALF OF THE DAY...BEFORE THE THUNDERSTORM THREAT ENDS IN ASSOCIATION WITH SHORTWAVE RIDGING BY THIS EVENING. OTHERWISE...A WEAK MID LEVEL TROUGH FROM NW MEXICO INTO NM WILL MOVE SEWD TOWARD THE LOWER RIO GRANDE VALLEY LATE IN THE PERIOD. GRADUAL MOISTENING/ DESTABILIZATION NEAR THE LOWER TX COAST COULD SUPPORT AN ISOLATED THUNDERSTORM THREAT BY EARLY THURSDAY JUST OFFSHORE. ..THOMPSON.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 16:11:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 11:11:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131610 SWODY1 SPC AC 131608 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1008 AM CST WED DEC 13 2006 VALID 131630Z - 141200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH IS IN PLACE ACROSS MOST OF THE NATION TODAY...WITH WATER VAPOR IMAGERY SHOWING SEVERAL EMBEDDED FEATURES TRACKING ACROSS THE COUNTRY. ONE STRONG UPPER JET AND ASSOCIATED VORT MAX ARE MOVING ASHORE ALONG THE WA COAST THIS MORNING. STRONG ONSHORE FLOW AND COLD TEMPERATURES ALOFT WILL MAINTAIN A RISK OF ISOLATED THUNDERSTORMS OVER THIS REGION THROUGH AFTERNOON. WEAK SURFACE BAROCLINIC ZONE IS MOVING SLOWLY SOUTHEASTWARD ACROSS THE CAROLINAS. SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP AHEAD OF THIS BOUNDARY...ESPECIALLY OVER THE GULF STREAM IMMEDIATELY OFFSHORE. NEVERTHELESS...MODELS SUGGEST WEAK BUT SUFFICIENT CAPE VALUES FOR THE THREAT OF ISOLATED THUNDERSTORMS ALONG THE IMMEDIATE CAROLINA COAST...INTO PARTS OF SOUTHEAST GA AND NORTHEAST FL. NO SEVERE STORMS ARE ANTICIPATED. ..HART.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 19:19:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 14:19:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131920 SWODY1 SPC AC 131918 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0118 PM CST WED DEC 13 2006 VALID 132000Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SOUTH ATLANTIC COAST... SOUTHERN PERIPHERY OF WEAKENING LARGE-SCALE TROUGH HAS SHIFTED EAST OF THE SOUTH CENTRAL APPALACHIANS...AND IS EXPECTED TO PROGRESS OFF SOUTHERN MID ATLANTIC COASTAL AREAS EARLY THIS EVENING. FORCING MAY STILL EVENTUALLY SUPPORT SCATTERED THUNDERSTORMS. BUT...THE BOUNDARY LAYER OVER THE COASTAL WATERS IS STILL IN THE PROCESS OF MODIFYING...AND IT APPEARS MOST LIKELY THAT THIS WILL OCCUR WELL OFFSHORE...PROBABLY NEAR THE GULF STREAM. ...PACIFIC NORTHWEST... INCREASINGLY ANTICYCLONIC FLOW IS DEVELOPING NORTHEASTWARD TOWARD THE NORTHERN PACIFIC COAST...AND RISK OF THUNDERSTORMS ALREADY APPEARS TO BE DIMINISHING. POTENTIAL IS EXPECTED TO BECOME NEGLIGIBLE BY THE 14/00-03Z TIME FRAME...AS LOW-LEVEL ONSHORE FLOW WEAKENS AND TEMPERATURES IN THE LOWER/MID TROPOSPHERE WARM... STABILIZING LAPSE RATES. ..KERR.. 12/13/2006  From swody1 at goshenarc.org Thu Dec 14 00:35:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 19:35:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140035 SWODY1 SPC AC 140032 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 PM CST WED DEC 13 2006 VALID 140100Z - 141200Z ...NO TSTM AREAS FORECAST... ...WA... ISOLATED CG LIGHTNING STRIKES HAVE BEEN OCCURRING ON THE OLYMPIC PENINSULA OVER THE PAST COUPLE OF HOURS. THIS ACTIVITY IS PROBABLY ASSOCIATED WITH INTENSE OROGRAPHIC FORCING AND WEAK DESTABILIZATION IN MOIST ONSHORE FLOW REGIME. SLIGHT RIDGING/WARMING ALOFT IS FORECAST ACROSS THE REGION THE REMAINDER OF TONIGHT AND THIS SHOULD GENERALLY LIMIT TSTMS DESPITE A CONTINUATION OF MOIST ONSHORE FLOW. ...FL... WEAK WARM AIR ADVECTION/ISENTROPIC LIFT WILL PERSIST ACROSS RESIDUAL FRONTAL ZONE OVER NRN FL. EVENING SOUNDINGS EXHIBIT A MOIST AIR MASS SOUTH OF THE FRONT OVER CNTRL SECTIONS OF THE PENINSULA. A VARIETY OF MODEL GUIDANCE SUGGESTS SOME POTENTIAL WILL EXIST FOR WIDELY SCATTERED CONVECTION ACROSS THE REGION TONIGHT. HOWEVER...WEAK LAPSE RATES AND LIMITED FORCING SHOULD KEEP ANY TSTM ACTIVITY QUITE ISOLATED. ..CARBIN.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 05:45:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 00:45:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140546 SWODY1 SPC AC 140543 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1143 PM CST WED DEC 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... FAST-MOVING WAVE TRAIN WILL CONTINUE ACROSS THE NRN STATES THIS PERIOD AS A LEAD IMPULSE...CURRENTLY MOVING ACROSS THE NRN PRAIRIES...SPREADS EWD AND AMPLIFIES OVER THE GREAT LAKES THROUGH EARLY FRIDAY. ANOTHER STRONG STORM SYSTEM...NOW MAKING STEADY EWD PROGRESS ACROSS THE ERN PACIFIC...WILL MAKE IT TO THE NORTHWEST COAST TODAY WITH STRONG MID LEVEL HEIGHT FALLS DEVELOPING INLAND TO THE NRN GREAT BASIN AND NRN ROCKIES THROUGH LATE TONIGHT. SOUTH OF THE FASTER MID LEVEL FLOW...A BROAD UPPER TROUGH AND MID LEVEL SHEAR ZONE IS FORECAST TO EVOLVE ACROSS MEXICO AND THE NWRN GULF. WEAK DISTURBANCES EMANATING FROM THIS TROUGH WILL TRANSLATE EWD OVER THE ERN GULF AND FL TODAY...LIKELY ENHANCING ASCENT NEAR AND SOUTH OF RESIDUAL DEEP-LAYER FRONTAL ZONE. ...FL... LOW LEVEL ELY FETCH OFF THE ATLANTIC WILL MAINTAIN 65-70F DEWPOINTS ACROSS CNTRL AND SRN FL TODAY. DIURNAL HEATING SHOULD CONTRIBUTE TO THE DEVELOPMENT OF INSTABILITY WITH FORECAST SOUNDINGS DEPICTING MUCAPE OF 800-1200 J/KG POSSIBLE. GIVEN WEAK CAP AND POSSIBILITY OF MODEST BACKGROUND ASCENT FROM SRN STREAM IMPULSES...EXPECT AT LEAST SCATTERED TSTM DEVELOPMENT THROUGH THE AFTERNOON. EFFECTIVE BULK SHEAR MAGNITUDES OF AROUND 30KT COULD SUPPORT ISOLATED PERSISTENT MULTICELLULAR STORMS...PERHAPS GENERATING GUSTY WINDS...BUT LAPSE RATES AND LACK OF STRONGER LOW LEVEL FLOW SHOULD NEGATE HIGHER PROBABILITY SEVERE THREAT. ...PAC NW... ONSHORE FLOW AND WARM AIR ADVECTION WILL INTENSIFY THROUGH THE DAY FROM NRN CA ACROSS WRN WA AHEAD OF THE NEXT STRONG SHORT WAVE TROUGH APPROACHING THE COAST. INSTABILITY WILL LIKELY REMAIN TOO MARGINAL TO SUPPORT CG LIGHTNING UNTIL AFTER THE PASSAGE OF THE STRONGER DYNAMIC FORCING ASSOCIATED WITH THE UPPER TROUGH. STRONG OROGRAPHIC FORCING AND LOWERING STATIC STABILITY ASSOCIATED WITH MID LEVEL COLD AIR ADVECTION IN THE WAKE OF THE STRONGER HEIGHT FALLS SHOULD LEAD TO AT LEAST WIDELY SCATTERED TSTM ALONG THE COAST AND INTO THE COAST RANGES THROUGH TONIGHT. ...UPPER MS VALLEY TO GREAT LAKES... A FAST-MOVING POCKET OF STRONG DYNAMIC FORCING AND WEAK DESTABILIZATION ON THE NOSE OF NARROW BUT INTENSE JET STREAK WILL CONTINUE TO SWEEP EAST FROM SD TO MN THROUGH DAYBREAK. THIS FEATURE HAS SPAWNED SPORADIC LIGHTNING WITH A FEW HIGH WIND GUSTS OBSERVED AT THE SURFACE. NAM-WRF HINTS THAT ISOLATED CONVECTION MAY PERSIST AS THIS SYSTEM MOVES EAST AND AMPLIFIES THROUGH THE DAY. HOWEVER...LACK OF GREATER INSTABILITY AND FAST MOVEMENT OF THE IMPULSE SHOULD LIMIT LIGHTNING COVERAGE TO LESS THAN 10 PERCENT ACROSS THE REGION. ..CARBIN.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 13:03:25 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 08:03:25 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141302 SWODY1 SPC AC 141300 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0700 AM CST THU DEC 14 2006 VALID 141300Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MODERATELY AMPLIFIED BUT PROGRESSIVE REGIME WILL PREVAIL ACROSS NOAM THROUGH FRIDAY...WITH DOMINANT NRN STREAM JET. A STRONG IMPULSE IN THE JET OVER THE NE PACIFIC...CROSSING 140W...WILL CONTINUE E OR SLIGHTLY N OF E INTO CANADIAN RCKYS/WRN MT BY 12Z FRIDAY. THE WEAKER SRN BRANCH...LOWER AMPLITUDE DISTURBANCE NOW OVER THE LWR RIO GRANDE SHOULD MOVE MORE SLOWLY INTO THE WRN GULF. ...CNTRL/SRN FL... LOW LEVEL ESE FLOW OFF THE ATLANTIC WILL MAINTAIN 65-70F DEWPOINTS ACROSS CNTRL AND SRN FL TODAY...WHERE MODEST DAYTIME HEATING SHOULD BOOST MUCAPE TO AROUND 1000 J/KG. LARGE SCALE FORCING FOR ASCENT WILL REMAIN WEAK WITH WEAK UPR LEVEL RIDGING DOWNSTREAM FROM RIO GRANDE TROUGH. BUT WITH LIMITED INHIBITION...EVEN WEAK LOW LEVEL CONVERGENCE INVOF OF OLD FRONTAL ZONE MAY SUPPORT CONVECTIVE DEVELOPMENT DEEP ENOUGH TO YIELD THUNDER. 30 KT DEEP WLY SHEAR MAY ALSO SUPPORT A FEW LONGER-LIVED UPDRAFTS...BUT WEAK LAPSE RATES/LOW LEVEL FLOW SHOULD LIMIT THREAT FOR SEVERE. ...WRN WA/ORE... COLD FRONT ASSOCIATED WITH WELL-DEFINED NE PACIFIC FRONTAL WAVE WILL MOVE ACROSS WRN WA AND ORE DURING THE MID TO LATE EVENING. ATTENDANT PRECIP BAND MAY CONTAIN SUFFICIENT VERTICAL DEVELOPMENT TO SUPPORT ISOLATED EMBEDDED THUNDER. A GREATER LIKELIHOOD FOR THUNDER WILL...HOWEVER...LIKELY AWAIT ARRIVAL OF FAST...COOL AND UNSTABLE POST-FRONTAL CYCLONIC FLOW REGIME LATER TONIGHT/EARLY FRIDAY... MAINLY OVER THE WA/ORE CASCADES. ...UPR MS VLY/UPR GRT LKS... MID LEVEL LAPSE RATES SHOULD GRADUALLY DIMINISH ALONG PATH OF FAST-MOVING NRN STREAM IMPULSE CROSSING THE UPR MS VLY THIS MORNING. SOME CONVECTION LIKELY WILL PERSIST WITH FEATURE AS IT MOVES FARTHER E AND AMPLIFIES ACROSS SRN MN/SRN WI/NRN IA/LK MI AND WRN LWR MI LATER TODAY. LIMITED DEGREE OF INSTABILITY SHOULD...HOWEVER...KEEP ANY ASSOCIATED LIGHTNING COVERAGE ISOLATED DESPITE AMPLIFICATION OF UPR SYSTEM. ...S TX... LOW CLOUDS SHOULD LIMIT HEATING/HELP MAINTAIN CAP...THEREBY PRECLUDING WIDESPREAD DEEP CONVECTIVE DEVELOPMENT AS WEAK UPR TROUGH CROSSES REGION LATER TODAY. ..CORFIDI.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 16:04:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 11:04:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141604 SWODY1 SPC AC 141602 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1002 AM CST THU DEC 14 2006 VALID 141630Z - 151200Z ...NO SVR TSTM AREAS FORECAST... STRONG SYSTEMS CONTINUE TO MOVE RAPIDLY EWD ACROSS NRN U.S. AND SRN CANADA. S OF 40N...CONUS UNDER THE INFLUENCE OF A WEAKER SUBTROPICAL WAVE TRAIN. SURFACE RIDGING FROM MID ATLANTIC STATES TO SRN PLAINS CONFINING ANY SIGNIFICANT LOW LEVEL MOISTURE AND INSTABILITY TO FAR S TX AND THE FL PENINSULA. AREA OF GREATEST THUNDERSTORM POTENTIAL THIS FORECAST PERIOD SHOULD BE SRN FL WHERE LOW LEVEL SELYS HAVE IMPORTED A MOIST BUT ONLY MARGINALLY UNSTABLE AIR MASS. WITH APPROACH OF THE WEAK EMBEDDED S/WV TROUGH NOTED IN WV OVER SRN TX...THUNDERSTORM POTENTIAL SHOULD INCREASE THIS AFTERNOON SRN FL. LIMITED HEATING...WEAK LAPSE RATES AND MARGINAL SHEAR PRECLUDES ANY SEVERE THUNDERSTORM THREAT. NEXT IN CURRENT SERIES OF DEEP CYCLONES MOVES ACROSS VANCOUVER ISLAND THIS EVENING BRINGING VERY STRONG WINDS INLAND PAC NW. WEAK INSTABILITY WILL LIMIT ANY THUNDERSTORM ACTIVITY TO COASTAL AREAS...PRIMARILY TONIGHT IN THE POST-FRONTAL ONSHORE FLOW. WHILE THERE COULD BE AN ISOLATED THUNDERSTORM FAR S TX THRU MID AFTERNOON...MOST OF THE ACTIVITY SHOULD REMAIN OVER THE GULF AND TO THE S AS THE MID LEVEL S/WV CURRENTLY CROSSING S TX MOVES ON TO THE E. ..HALES.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 19:30:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 14:30:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141930 SWODY1 SPC AC 141928 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0128 PM CST THU DEC 14 2006 VALID 142000Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...PACIFIC NW... CURRENT WATER VAPOR IMAGERY INDICATES STRONG SHORT WAVE TROUGH APPROACHING VANCOUVER ISLAND AND THE WA COAST WITH A CLUSTER OF TSTMS OBSERVED NEAR 46N/131W AS OF 19Z PER OCEANIC LIGHTNING DATA. THIS FEATURE IS FORECAST TO MOVE ONTO THE COAST TONIGHT WITH LOW-LEVEL ONSHORE FLOW DEVELOPING IN WAKE OF ATTENDANT SURFACE PACIFIC FRONT. DESTABILIZATION ARISING FROM COOLING MID-LEVELS AND MOISTENING IN THE LOW-LEVELS COUPLED WITH FORCING ALONG FRONT AND WINDWARD SIDE OF COASTAL RANGE SHOULD SUPPORT A FEW EMBEDDED TSTMS OVERNIGHT ALONG AND SLIGHTLY INLAND OF THE COAST. ...DEEP S TX... LOW LATITUDE SHORT WAVE TROUGH CURRENTLY W OF BRO WILL CONTINUE EWD INTO THE GULF OF MEXICO TONIGHT. TSTMS ARE ONGOING THIS AFTERNOON ACROSS NRN PORTIONS OF NUEVO LEON/TAMAULIPAS MEXICO WITH ACTIVITY GRADUALLY DEVELOPING NEWD TOWARD THE RIO GRANDE VALLEY AND DEEP S TX. AMBIENT LOW-LEVEL AIR MASS REMAINS MOIST AND WEAKLY UNSTABLE WITH MLCAPES OF AROUND 500 J/KG. EXPECT THE THREAT OF TSTMS TO PERSIST THROUGH THE AFTERNOON...PERHAPS INTO EARLY EVENING BEFORE SHORT WAVE TROUGH AND ASSOCIATED STRONGER FORCING SHIFTS E OF REGION. ...CNTRL/SRN FL PENINSULA... AFTERNOON SURFACE OBSERVATIONS INDICATE WEAK LOW-LEVEL BOUNDARY FROM NEAR MLB SWWD TO SRQ WITH SEVERAL NW-SE ORIENTED CONFLUENCE ZONES PRESENT IN VISIBLE SATELLITE IMAGERY ALONG THE SERN FL COAST. LOW-LEVEL AIR MASS ALONG AND S OF THIS PRIMARY BOUNDARY IS QUITE MOIST WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S...HOWEVER WEAK LAPSE RATES ARE LIMITING OVERALL INSTABILITY. WATER VAPOR IMAGERY INDICATES A COUPLE OF WEAK IMPULSES PRECEDING S TX IMPULSE /SEE PREVIOUS SECTION/...ONE OF WHICH IS NEAR GRAND BAHAMA AND THE OTHER NEAR 24N/84W. WEAK FORCING ASSOCIATED WITH THESE FEATURES IN CONJUNCTION WITH THE MOIST LOW-LEVEL ENVIRONMENT IS EXPECTED TO REMAIN SUPPORTIVE OF ISOLATED/SCATTERED TSTMS ALONG AND S OF FRONTAL ZONE THIS AFTERNOON AND TONIGHT. ..MEAD.. 12/14/2006  From swody1 at goshenarc.org Fri Dec 15 00:59:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 19:59:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150100 SWODY1 SPC AC 150058 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 PM CST THU DEC 14 2006 VALID 150100Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...FL... CONFLUENT LOW LEVEL SLY FLOW ACROSS SRN/CNTRL PARTS OF THE PENINSULA SHOULD CONTINUE TO SUPPORT SHOWERS AND PERHAPS OCNL TSTMS IN MOIST AIR MASS ACROSS FL TONIGHT. WEAK LAPSE RATES ARE PROBABLY LIMITING UPDRAFT STRENGTH AND CHARGE SEPARATION. HOWEVER...PASSAGE OF LOW AMPLITUDE DISTURBANCES ALOFT COULD STILL ENHANCE MESOSCALE FORCING AND STORM FORMATION IN MODESTLY SHEARED DEEP-LAYER FLOW. A COUPLE OF STRONGER STORMS WITH CG LIGHTNING STRIKES STILL APPEAR POSSIBLE THROUGH THE REMAINDER OF THE FORECAST PERIOD. ...NW COAST... ANOTHER POWERFUL CYCLONE WAS WRAPPING-UP NEAR VANCOUVER ISLAND THIS EVENING WITH 100-110KT MID LEVEL JET SPREADING ACROSS WRN WA/ORE. GIVEN POTENTIAL INSTABILITY AND INTENSE DYNAMIC FORCING/COOLING ALOFT...AND PERSISTENT MOIST ONSHORE AND UPSLOPE FLOWS...SPORADIC TSTMS SHOULD EXIST ACROSS THE REGION THROUGH THE NIGHT. ...S TX... A COUPLE OF STORMS HAVE FORMED BENEATH WEAK MID LEVEL TROUGH AXIS ACROSS THE MIDDLE TX COASTAL PLAIN THIS EVENING. DRY AIR IN THE MID LEVELS AND WARM AND MOIST BOUNDARY LAYER ARE CONTRIBUTING TO MUCAPE NEARING 2000 J/KG PER CRP EVENING SOUNDING. WITH LOSS OF DAYTIME HEATING IT IS UNCERTAIN HOW LONG CONVECTION CAN PERSIST. GIVEN THE WEAK BACKGROUND ASCENT ASSOCIATED WITH THE MID LEVEL WAVE AND LACK OF CAP EVIDENT ON THE CRP SOUNDING...EXPECT AT LEAST ANOTHER HOUR OR TWO OF TSTM POTENTIAL ACROSS THE REGION. ..CARBIN.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 05:45:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 00:45:46 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150546 SWODY1 SPC AC 150544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 PM CST THU DEC 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG HEIGHT FALLS ARE FORECAST TO SPREAD FROM THE INTERIOR NORTHWEST ACROSS THE NRN ROCKIES/HIGH PLAINS SWWD TO THE GREAT BASIN AS LARGE SCALE POSITIVE-TILT TROUGH EVOLVES ACROSS THE WEST THIS PERIOD. ANOTHER PROGRESSIVE SHORT WAVE TROUGH AND ASSOCIATED COLD FRONT WILL TRANSLATE EWD FROM THE GREAT LAKES TO OFF THE NEW ENGLAND COAST BY SATURDAY MORNING. BROAD UPPER TROUGH ACROSS TX/NRN MEXICO WILL DRIFT EWD OVER THE GULF TODAY AS RESIDUAL LARGE SCALE BAROCLINIC ZONE BISECTING FL SHIFTS GRADUALLY SOUTH. ...PACIFIC NW COAST... MOIST ONSHORE FLOW IN THE LOW-LEVELS COUPLED WITH VERY COLD MID-LEVEL TEMPERATURES OF -34C TO -38C AT 500 MB WILL AGAIN RESULT IN STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY. WITH STRONGER FORCING PASSING EAST OF THE REGION THROUGH THE DAY AND RIDGING ALOFT BUILDING INTO THE AREA BY TONIGHT...TSTM POTENTIAL SHOULD DIMINISH WITH TIME. ...SRN FL PENINSULA... MOIST AND UNSTABLE CONDITIONS ARE EXPECTED ALONG AND SOUTH OF WEAK LOW-LEVEL BOUNDARY PUSHING SWD THROUGH THE REGION. CONVERGENCE ALONG THIS FRONT...COUPLED WITH LITTLE OR NO CONVECTIVE INHIBITION... SHOULD RESULT IN TSTM ACTIVITY EMBEDDED WITHIN AREA OF SHOWERS. ...PA/NY/WRN NEW ENGLAND... WEAK INSTABILITY /MUCAPE 150-200 J PER KG/ IS FORECAST TO DEVELOP ACROSS PARTS OF THE NORTHEAST GIVEN UNSEASONABLY WARM/MOIST BOUNDARY LAYER AND COLD TEMPERATURES ALOFT. ASCENT ASSOCIATED WITH THE MIGRATORY SHORT WAVE TROUGH AND COLD FRONT SHOULD PROVE SUFFICIENT FOR SCATTERED CONVECTION AND POSSIBLY A FEW LIGHTNING STRIKES THROUGH THE AFTERNOON. SREF GUIDANCE INDICATES MOST LIKELY AREAS TO EXPERIENCE ISOLATED TSTM DEVELOPMENT ARE FROM ERN LAKE ONTARIO...SWD TO NERN PA...AND EWD ACROSS THE HUDSON VALLEY IN THE 19-22Z TIME FRAME. ISOLATED SMALL HAIL ALSO APPEARS POSSIBLE GIVEN POTENTIAL FOR STEEP LAPSE RATES AND LOW FREEZING LEVELS. ..CARBIN.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 13:02:03 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 08:02:03 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151302 SWODY1 SPC AC 151259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST FRI DEC 15 2006 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG BC/WRN MT TROUGH EXPECTED TO MOVE E/NE ACROSS AB/SK AND NRN MT TODAY BEFORE CONTINUING E INTO WRN MB SATURDAY MORNING. MID/UPR LEVEL FLOW OVER MUCH OF THE WRN AND CNTRL U.S WILL...HOWEVER...BACK WITH TIME AS POTENT SYSTEM NOW ALONG 140W AMPLIFIES AND CONTINUES E TOWARD THE CST. IN THE E...STLT LOOPS SUGGEST UPR GRT LKS SYSTEM WILL ALSO AMPLIFY TODAY AS IT CONTINUES E TOWARD THE N ATLANTIC CST. IN THE WEAKER SRN BRANCH...IMPULSE NOW OVER THE FAR WRN GULF EXPECTED TO DRIFT ONLY SLOWLY E THROUGH THE PERIOD. ...PAC NW INTO NRN RCKYS... STLT LOOPS SHOW COMPLEX VORTICITY PATTERN PRESENT ATTM OFF THE WA/ORE CST. ONE LOBE APPEARS TO BE DEVELOPING SE FROM AREA ABOUT 250 NM NW OF PDX...WITH AN UPSTREAM VORT LIKELY MORE CLOSELY ASSOCIATED WITH MAIN AMPLIFYING TROUGH CLOSE TO 43N/140W. DEEP...COLD CYCLONIC ONSHORE FLOW WITH MID-LEVEL TEMPERATURES AOB MINUS 35C WILL MAINTAIN THREAT FOR THUNDER ALONG THE CASCADES AND CSTL RANGES AS LEAD VORT MOVES ASHORE LATER TODAY. FARTHER E...MORE ISOLATED ACTIVITY MAY PERSIST FOR A FEW MORE HOURS INVOF FRONTAL BAND ASSOCIATED WITH BC/MT TROUGH. SHORTWAVE RIDGING DOWNSTREAM FROM AMPLIFYING TROUGH SHOULD REDUCE THUNDER POTENTIAL OVER WRN WA/ORE THIS EVENING. ...SRN FL... MOIST...SLIGHTLY UNSTABLE AND WEAKLY CAPPED ENVIRONMENT SHOULD ONCE AGAIN SUPPORT SHOWERS AND A FEW DIURNALLY-ENHANCED THUNDERSTORMS ALONG AND SOUTH OF WEAK BOUNDARY MOVING S ACROSS REGION. ...NRN PA/UPSTATE NY/WRN NEW ENGLAND... WEAK INSTABILITY /MUCAPE 150-200 J PER KG WITH TOTAL TOTALS AOA 52/ SHOULD DEVELOP OVER THE ERN GRT LKS LATER TODAY AS UPR SYSTEM AMPLIFIES ABOVE SEASONABLY WARM/MOIST BOUNDARY LYR PRESENT OVER REGION. STRENGTHENING ASCENT MAY YIELD SCATTERED CONVECTION SUFFICIENTLY DEEP TO PRODUCE A FEW LIGHTNING STRIKES THIS AFTN AND EVENING. ISOLATED SMALL HAIL ALSO APPEARS POSSIBLE GIVEN POTENTIAL FOR STEEP LAPSE RATES AND LOW FREEZING LEVELS. ..CORFIDI/TAYLOR.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 16:05:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 11:05:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151606 SWODY1 SPC AC 151604 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1004 AM CST FRI DEC 15 2006 VALID 151630Z - 161200Z ...NO SVR TSTM AREAS FORECAST... INTENSE SYSTEM THAT MOVED ONTO PAC NW COAST LAST NIGHT CURRENTLY MOVING ACROSS SRN PRAIRIE PROVINCES OF SWRN CANADA WITH A STRONG COLD FRONT TRAILING SWWD FROM CENTRAL MT TO NWRN NV. ANOTHER VIGOROUS UPPER TROUGH INITIALLY GREAT LAKES ROTATES EWD ACROSS NERN U.S. BY TONIGHT. BOTH OF THE UPPER SYSTEMS NRN TIER OF CONUS WILL BE ACCOMPANIED BY ONLY MARGINAL INSTABILITY. OTHER THAN ISOLATED LIGHTNING STRIKES ACROSS NERN U.S. WITH UPPER TROUGH AND POSSIBLY NEAR FRONTAL BAND MT TO NV...THE ONLY AREA ATTM THAT THERE APPEARS A CHANCE OF MORE THAN A FEW STRIKES WILL BE THE AREA OF COASTAL OR/WA WHERE A CONTINUED BUT WEAKENING ONSHORE FLOW OF MOIST/MARGINALLY UNSTABLE COLD AIR WILL PERSIST THRU THE PERIOD AHEAD OF AMPLIFYING UPPER TROUGH ALONG THE WEST COAST. VERY MOIST AIR REMAINS S FL...HOWEVER INSTABILITY AND SHEAR HAS WEAKENED PAST 24 HOURS. A FEW THUNDERSTORMS ARE LIKELY THIS AFTERNOON/EVENING...WHERE SOME HEATING CAN OCCUR THRU THE EXTENSIVE MID/UPPER LEVEL CLOUDINESS. ..HALES.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 19:41:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 14:41:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151942 SWODY1 SPC AC 151939 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0139 PM CST FRI DEC 15 2006 VALID 152000Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...S FL AND THE KEYS... MESOANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATE ONE LOW LEVEL BOUNDARY ALONG THE FL STRAITS AND A SECONDARY WEAKER CONFLUENCE ZONE FROM NEAR PBI SWWD TOWARD EYW. DESPITE A MOIST LOW-LEVEL AIR MASS...CONSIDERABLE CLOUDS AND WEAK LAPSE RATES HAVE LIMITED DESTABILIZATION WITH MLCAPES AOB 500 J/KG. STILL SOME THREAT OF ISOLATED TSTMS WILL EXIST THIS AFTERNOON AND TONIGHT OWING TO PERSISTENT LOW-LEVEL CONVERGENCE ALONG THESE BOUNDARIES...AND PERHAPS INCREASED LARGER-SCALE FORCING ASSOCIATED WITH WEAK IMPULSE EVIDENT IN WATER VAPOR IMAGERY OVER WRN CUBA. ...HUDSON VALLEY INTO WRN NEW ENGLAND... RADAR AND LIGHTNING DATA INDICATE THAT CONVECTION HAS RECENTLY DEEPENED SUFFICIENTLY TO SUPPORT TSTM DEVELOPMENT. AIR MASS REMAINS DRY...HOWEVER DAYTIME HEATING HAS CONTRIBUTED TO THE DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND RESULTANT WEAK CONDITIONAL INSTABILITY. EXPECT ONGOING CONVECTION TO PERSIST AHEAD OF COLD FRONT INTO WRN NEW ENGLAND THIS EVENING...DRIVEN BY THE MARGINAL INSTABILITY AND STRONG FORCING AHEAD OF MIGRATORY SHORT WAVE TROUGH. ACTIVITY SHOULD TEND TO DISSIPATE LATER THIS EVENING AS LOW-LEVEL LAPSE RATES WEAKEN. ...PACFIC NW COAST... NEXT STRONG SYSTEM NEAR 42N/134W IS FORECAST TO DIG SEWD ACROSS THE ERN PACIFIC TONIGHT WITH LOW-LEVEL ONSHORE FLOW WEAKENING IN RESPONSE TO APPROACH OF ATTENDANT SURFACE CYCLONE. BOTH RUC OBJECTIVE FIELDS AND VISIBLE SATELLITE IMAGERY SUGGEST THAT LAPSE RATES ARE QUITE STEEP...THOUGH LARGE-SCALE FORCING FOR ASCENT WILL REMAIN MARGINAL. SOME POTENTIAL FOR A FEW LIGHTNING STRIKES WILL EXIST THIS AFTERNOON INTO EVENING...HOWEVER THIS THREAT APPEARS TOO MARGINAL TO WARRANT A GENERAL THUNDER AREA. ...NRN ROCKIES INTO GREAT BASIN... SOME POTENTIAL WILL EXIST FOR A FEW LIGHTNING STRIKES WITHIN POST FRONTAL AIR MASS OWING LARGELY TO STRONG MID-LEVEL COOLING AND RESULTANT STEEPENING LAPSE RATES. THIS THREAT IS EXPECTED TO REMAIN QUITE LIMITED AND NO THUNDER AREA WILL BE INCLUDED. ..MEAD.. 12/15/2006  From swody1 at goshenarc.org Sat Dec 16 00:54:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 19:54:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160055 SWODY1 SPC AC 160053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 PM CST FRI DEC 15 2006 VALID 160100Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...FL... MOISTURE REMAINS QUITE HIGH ACROSS SOUTH FL WHERE ILL-DEFINED MID LEVEL DISTURBANCES OF SUBTROPICAL ORIGIN HAVE BEEN PROMOTING AREAS OF CONVECTION FOR THE PAST FEW DAYS. ANOTHER AREA OF SHOWERS AND EMBEDDED TSTMS APPEARS TO BE INCREASING THIS EVENING FROM THE DRY TORTUGAS TO THE FL STRAITS. GIVEN THIS LATEST TREND...AND RECENT GUIDANCE ALSO INDICATING A CONTINUING CHANCE FOR CONVECTIVE QPF ACROSS THE SRN TIP OF FL...A SMALL TSTM AREA WILL BE MAINTAINED. ..CARBIN.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 05:18:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 00:18:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160519 SWODY1 SPC AC 160516 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 PM CST FRI DEC 15 2006 VALID 161200Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVE-TILT LARGE SCALE TROUGH WILL BECOME FIRMLY ESTABLISHED ACROSS THE WRN CONUS THIS PERIOD AS BROAD UPPER RIDGE DEVELOPS ACROSS MUCH OF THE REST NATION EAST OF THE ROCKIES. IMPULSE ASSOCIATED WITH INTENSE THURSDAY/FRIDAY STORM ACROSS THE PACIFIC NORTHWEST WILL CONTINUE TO BREAK AWAY FROM THE LARGER SCALE WRN TROUGH...WITH STRONGEST HEIGHT FALLS SPREADING ACROSS ONTARIO AND WRN QUEBEC. MEANWHILE...ANOTHER POTENT PACIFIC PERTURBATION... CURRENTLY EVIDENT ON WATER VAPOR SATELLITE IMAGERY NEAR 35N 131W...WILL CROSS THE CA COAST THIS MORNING BEFORE MOVING TOWARD THE GREAT BASIN THROUGH TONIGHT. THIS IMPULSE IS FORECAST TO INDUCE CYCLOGENESIS ALONG A DEEP-LAYER BAROCLINIC ZONE SITUATED FROM THE INTERMOUNTAIN WEST TO THE LOWER CO RIVER VALLEY THROUGH EARLY SUNDAY. DESPITE LARGE SCALE HEIGHT RISES FORECAST ACROSS THE NRN GULF AND SRN U.S....A COMPACT SRN STREAM VORT MAX /MOVING EWD ACROSS THE CNTRL GULF OF MEXICO ATTM/ SHOULD PASS OVER SWRN FL THROUGH LATE TODAY. THIS FEATURE MAY ENHANCE DEEP-LAYER ASCENT ALONG A WEAK BAROCLINIC ZONE SITUATED ACROSS THE FL STRAITS. ...NV/UT... A COUPLE OF TSTMS APPEAR POSSIBLE OVER PARTS OF SRN/ERN NV...AND PERHAPS WRN UT...THROUGH THIS EVENING AS LOW STATIC STABILITY ACCOMPANYING UPPER TROUGH ACTS TO ENHANCE LIFT/OROGRAPHIC FORCING NEAR DEEP-LAYER FRONT. MODEST LAPSE RATES AND MOISTENING NEAR THE FRONT SHOULD PROVE ADEQUATE FOR VERY MARGINAL INSTABILITY...BUT PERHAPS ENOUGH TO PROMOTE SPORADIC CG LIGHTNING GIVEN EXPECTED DYNAMICS. ...FL... A MOIST AND WEAKLY UNSTABLE AIR MASS SHOULD REMAIN ALONG A NEARLY STALLED BOUNDARY ACROSS S FL/FL STRAITS. LOW-LEVEL CONVERGENCE MAY STRENGTHEN ALONG THE BOUNDARY WITH APPROACH OF SRN STREAM IMPULSE AND RESULT IN ISOLATED TO SCATTERED TSTMS. WEAK LAPSE RATES AND SHEAR WILL PRECLUDE ANY SEVERE THREAT. ..CARBIN.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 12:19:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 07:19:58 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161220 SWODY1 SPC AC 161218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0618 AM CST SAT DEC 16 2006 VALID 161300Z - 171200Z ...NO SVR TSTM AREAS FORECAST... COLD TROUGH WILL BE DEVELOPING INTO WRN U.S TODAY WITH MUCH OF ERN U.S. UNDER A SLOWLY BUILDING FLAT RIDGE. THE SUBTROPICAL STREAM ACROSS THE GOM AND SRN FL FORECASTED TO SLOWLY WEAKEN AS ONE LAST PERTURBATION TRAVERSES FL PENINSULA TODAY. ANY THUNDERSTORMS THIS FORECAST PERIOD WILL BE CONFINED TO FAR S FL WHERE A VERY MOIST AND WEAKLY UNSTABLE ENVIRONMENT EXISTS. SUFFICIENT LIFT ACROSS STATIONARY SFC BOUNDARY JUST S OF KEYS TO MAINTAIN A LOW THREAT OF EMBEDDED THUNDERSTORMS THRU THE AFTERNOON. ONLY OTHER AREA WHERE A FEW STRIKES COULD OCCUR...MOSTLY TONIGHT... WOULD BE SRN PLATEAU UNDER DEVELOPING COLD TROUGH. THREAT APPEARS TO BE TOO LIMITED TO SUPPORT A 10% COVERAGE. ..HALES.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 15:53:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 10:53:37 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161554 SWODY1 SPC AC 161551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0951 AM CST SAT DEC 16 2006 VALID 161630Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...CA COAST LATE THIS AFTERNOON INTO TONIGHT... WATER VAPOR AND IR IMAGERY SHOW A STRONG MID LEVEL TROUGH APPROACHING 35 N AND 125 W...AND THIS SYSTEM WILL MOVE INLAND OVER CENTRAL/SRN CA TONIGHT. COLD MID LEVEL TEMPERATURES AND STEEP LAPSE RATES ACCOMPANY THE MID LEVEL THERMAL TROUGH...AS EVIDENCED BY THE SWATH OF LOW-TOPPED CONVECTION W OF THE PRIMARY BAROCLINIC BAND JUST OFF THE CA COAST. THOUGH OCEANIC LIGHTNING DATA HAS SHOWN A PRONOUNCED DECREASE IN STRIKES SINCE 10Z...THERE WILL BE SOME THREAT FOR ADDITIONAL CONVECTION ALONG THE IMMEDIATE COAST AS THE TROUGH MOVES INLAND BY TONIGHT. ...S FL THROUGH TONIGHT... A LOW-LATITUDE SHORTWAVE TROUGH IS MOVING EWD FROM THE CENTRAL GULF OF MEXICO TOWARD FL. IN ADVANCE OF THIS TROUGH...A WEAK SURFACE FRONTAL WAVE ACROSS THE SE GULF AND FL STRAITS WILL PROVIDE A FOCUS FOR SOME DEEP CONVECTION THIS PERIOD GIVEN THE MOIST PROFILES AND WEAK INSTABILITY NOTED IN THE 12Z MIAMI AND KEY WEST SOUNDINGS. ..THOMPSON.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 19:30:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 14:30:31 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161931 SWODY1 SPC AC 161929 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0129 PM CST SAT DEC 16 2006 VALID 162000Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...CA COAST... STRONG MID-LEVEL TROUGH CONTINUES TO DIG SEWD TOWARD THE CNTR/SRN CA COAST WITH VISIBLE SATELLITE AND RUC OBJECTIVE FIELDS INDICATING A BROAD REGION OF OCEANIC CELLULAR CONVECTION WITHIN AN ENVIRONMENT OF STEEP LOW TO MID-LEVEL LAPSE RATES. THIS TROUGH IS FORECAST TO MOVE ONTO THE SRN CA COAST TONIGHT WITH STEEP LAPSE RATES MOVING INLAND. IT APPEARS THAT THE GREATEST THREAT OF TSTMS WILL EXIST ALONG THE IMMEDIATE COAST...THOUGH THE POTENTIAL FOR ISOLATED THUNDER WILL EXIST AS FAR E AS THE LOWER CO VALLEY. ...S FL AND THE KEYS... A MOIST LOW-LEVEL AIR MASS EXISTS ACROSS THE REGION THIS AFTERNOON...THOUGH CONSIDERABLE CLOUDINESS HAS LIMITED DESTABILIZATION. TSTMS CONTINUE TO INCREASE UPSTREAM FROM WRN CUBA NWD IN ASSOCIATION WITH LOW LATITUDE IMPULSE TRANSLATING THROUGH THE CNTRL/ERN GULF BASIN. EXPECT THAT THE THREAT OF ISOLATED/SCATTERED TSTMS WILL INCREASE OVERNIGHT AS THIS SYSTEM APPROACHES THE PENINSULA. OTHER STORMS WILL LIKELY PERSIST THROUGH THE AFTERNOON ALONG WEAK BOUNDARY NEAR AND E OF VRB. ..MEAD.. 12/16/2006  From swody1 at goshenarc.org Sun Dec 17 00:26:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 19:26:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170027 SWODY1 SPC AC 170025 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0625 PM CST SAT DEC 16 2006 VALID 170100Z - 171200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH WILL CONTINUE MOVING SLOWLY ACROSS THE WRN QUARTER OF THE CONUS...WHILE BROAD ZONE OF WSWLY FLOW PERSISTS ACROSS MOST OF THE REMAINDER OF THE CONUS. THOUGH A FEW SPORADIC LIGHTNING STRIKES MAY OCCUR NEAR/OFF THE W COAST...AND/OR INVOF THE CENTRAL/SRN FL COASTS...OVERALL LIGHTNING COVERAGE SHOULD REMAIN LOW ENOUGH THROUGH THE END OF THE PERIOD TO PRECLUDE ANY ISSUANCE OF THUNDER LINES. ..GOSS.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 05:12:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 00:12:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170513 SWODY1 SPC AC 170511 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 PM CST SAT DEC 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SPLIT FLOW REGIME ALOFT WILL CONTINUE TO EVOLVE ACROSS THE WRN CONUS. SEVERAL SHORT-WAVE TROUGHS WILL TRAVERSE THE U.S./CANADA BORDER IN THE NRN STREAM...WHILE THE SRN STREAM TROUGH OVER THE WRN CONUS REMAINS QUASI-STATIONARY AND TRENDS TOWARD THE DEVELOPMENT OF A CLOSED LOW OVER SRN CA. MEANWHILE...A WEAK UPPER DISTURBANCE INVOF FL/THE BAHAMAS WILL PERSIST WITHIN LARGER-SCALE RIDGE. THIS DISTURBANCE MAY BE ASSOCIATED WITH A FEW ONSHORE LIGHTNING STRIKES OVER S FL AND THE KEYS -- MAINLY DURING THE FIRST HALF OF THE PERIOD. ELSEWHERE...ASIDE FROM A FEW STRAY STRIKES OVER THE WEST IN CONJUNCTION WITH THE WRN UPPER TROUGH...DEEP/MOIST CONVECTION IS NOT ANTICIPATED. ..GOSS.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 12:31:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 07:31:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171232 SWODY1 SPC AC 171229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0629 AM CST SUN DEC 17 2006 VALID 171300Z - 181200Z ...NO SVR TSTM AREAS FORECAST... UPR RIDGING MOVING INTO PAC NW SUPPORTS THE SPLITTING OF WRN TROUGH. NRN PORTION OF TROUGH SHEARS ENEWD FROM ROCKIES INTO PLAINS WHILE CLOSED LOW DEVELOPS INTO SRN CA BY 12Z MON. WITH VERY LIMITED INSTABILITY ANY CONVECTION ASSOCIATED WITH TROUGH OVER THE W SHOULD BE SHALLOW WITH ONLY ISOLATED LIGHTNING STRIKES EXPECTED. TAIL END OF WEAK TROUGH IN SRN BRANCH WILL MAINTAIN THREAT OF SOME CONVECTION EMBEDDED IN THE VERY MOIST AIR MASS ACROSS SRN FL. ANY LIGHTNING SHOULD END BY EVENING AS UPPER SYSTEM MOVES OFF TO THE SE. ..HALES.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 16:29:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 11:29:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171629 SWODY1 SPC AC 171627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST SUN DEC 17 2006 VALID 171630Z - 181200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SCALE FLOW REGIME OVER THE CONUS WILL CHANGE LITTLE THIS PERIOD AS A MID LEVEL TROUGH OVER NV/CA EVOLVES GRADUALLY INTO A CLOSED LOW WITH LITTLE EWD MOVEMENT. A SERIES OF NRN STREAM WAVES WILL MOVE EWD ALONG THE U.S./CANADIAN BORDER...WITH SURFACE RIDGING/COLD FRONT EXPECTED TO SAG SWD ACROSS THE SRN PLAINS IN RESPONSE TO MID LEVEL CONFLUENT FLOW OVER THE NRN PLAINS. LOW-LEVEL MOISTURE /BOUNDARY LAYER DEWPOINTS IN THE 60S/ HAS SPREAD NWD ACROSS E TX INTO SE OK AND AR...BUT POOR LAPSE RATES AND RATHER WARM MID LEVEL TEMPERATURES WILL LIMIT ANY POTENTIAL FOR DEEP CONVECTION ALONG THE FRONTAL ZONE NEAR I-44. OTHERWISE...A SRN STREAM WAVE IS BEGINNING TO MOVE E OF THE FL PENINSULA...AND THE THREAT FOR ANY ADDITIONAL THUNDERSTORMS SHOULD REMAIN GENERALLY S/SE OF THE SE FL COAST AND KEYS. ..THOMPSON.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 19:41:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 14:41:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171942 SWODY1 SPC AC 171940 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST SUN DEC 17 2006 VALID 172000Z - 181200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS AND DISCUSSION... EVOLVING UPPER LOW OVER THE GREAT BASIN WILL CONTINUE SEWD INTO THE LOWER CO VALLEY TONIGHT...WHILE WAVE TRAIN REMAINS MORE PROGRESSIVE ACROSS CANADA. IN THE LOW-LEVELS...SURFACE HIGH WILL BUILD SEWD FROM THE NRN HIGH PLAINS INTO CNTRL PLAINS WITH COLD FRONT SLOWLY PUSHING SWD THROUGH THE MID MS VALLEY AND SRN PLAINS. A MOIST LOW-LEVEL AIR MASS EXISTS TODAY TO THE S OF COLD FRONT FROM CNTRL/ERN TX INTO THE OZARK PLATEAU. HOWEVER...12Z RAOBS INDICATE THE PRESENCE OF WARM MID-LEVEL TEMPERATURES AND RESULTANT WEAK LAPSE RATES. SOME SHOWER ACTIVITY WILL BE POSSIBLE OVERNIGHT AS SWLY LLJ REINTENSIFIES AND ENHANCES ISENTROPIC ASCENT NEAR AND N OF SURFACE FRONT FROM OK INTO MO/IL. THIS CONVECTION IS EXPECTED TO REMAIN TOO SHALLOW/WARM TO SUPPORT CHARGE SEPARATION. ELSEWHERE...LOW-LEVEL AIR MASS REMAINS MOIST ACROSS S FL...HOWEVER LARGE-SCALE SUBSIDENCE IN WAKE OF SHORT WAVE TROUGH PUSHING E OF THE BAHAMAS SHOULD SUPPRESS ANY CONVECTIVE DEVELOPMENT. FINALLY...SOME THREAT OF AN ISOLATED LIGHTNING STRIKE OR TWO WILL EXIST NEAR AND N OF THE FOUR CORNERS REGION AS HEIGHT FALLS AHEAD OF UPPER TROUGH CONTRIBUTE TO STEEPENING LAPSE RATES. THIS THREAT IS TOO MARGINAL TO WARRANT A GENERAL THUNDER AREA. ..MEAD.. 12/17/2006  From swody1 at goshenarc.org Mon Dec 18 00:38:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 19:38:57 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180039 SWODY1 SPC AC 180037 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0637 PM CST SUN DEC 17 2006 VALID 180100Z - 181200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... WATER VAPOR AND IR SATELLITE IMAGERY SHOWS DEVELOPING MID/UPPER LEVEL LOW OVER THE CA/NV REGION AS GEOPOTENTIAL HEIGHTS RISE OVER THE PACIFIC NORTHWEST. DOMINANT SWLY FLOW ALOFT EXTENDS FROM NRN BAJA REGION INTO THE GREAT LAKES OVER QUASISTATIONARY FRONT THAT EXTENDS FROM NRN VERMONT THROUGH SWRN MO/NERN OK INTO THE SRN HIGH PLAINS OF TX. SURFACE RIDGING OVER THE CAROLINAS EXTENDS WSWWD THROUGH THE WRN GULF INHIBITING LOW LEVEL MOISTURE RETURN. MODELS HINT AT INCREASING SWLY LOW LEVEL JET OVERNIGHT FROM ERN OK INTO SERN MO WHICH MAY ENHANCE ISOLATED SHALLOW CONVECTION/ISENTROPIC LIFT...BUT POOR LAPSE RATES WOULD INDICATE THE LOW POTENTIAL FOR ISOLATED LIGHTNING ACTIVITY. LATEST RAOB DATA SHOWS THAT 500 MB TEMPS NEAR MID LEVEL LOW CIRCULATION OVER CENTRAL CA ARE AROUND -28C. SHORT RANGE ENSEMBLE FORECASTS INDICATE THAT LIFTED INDICES OFF THE CENTRAL CA COAST MAY BE AROUND -2...THUS ISOLATED LIGHTNING ACTIVITY COULD OCCUR BUT THREAT REMAINS TOO MARGINAL THROUGH THE REMAINDER OF THE PERIOD TO WARRANT A GENERAL THUNDER AREA. ..MCCARTHY.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 05:42:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 00:42:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180543 SWODY1 SPC AC 180541 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST SUN DEC 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... CLOSED UPPER LOW IS FORECAST TO DEVELOP/DRIFT EWD ACROSS THE SWRN U.S. WITH TIME...WITH DOWNSTREAM RIDGE FORECAST OVER THE SERN HALF OF THE CONUS. MEANWHILE...MORE PROGRESSIVE FLOW REGIME IS EXPECTED ACROSS CANADA AND THE NRN U.S. WITHIN FASTER NRN BRANCH OF THE WLYS. AT THE SURFACE...MAIN FEATURE WILL BE AN ENE-WSW BAROCLINIC ZONE INITIALLY EXTENDING FROM SRN NEW ENGLAND WSWWD TO W TX. THIS FEATURE WILL CONTINUE MOVING SSEWD WITH TIME AS 1035 MB HIGH DRIFTS SLOWLY SWD ACROSS THE CONUS. THOUGH MOST OF THE COUNTRY WILL REMAIN STABLE WITH RESPECT TO DEEP MOIST CONVECTION...ISOLATED THUNDERSTORMS ARE FORECAST FROM THE FOUR CORNERS INTO W TX IN ASSOCIATION WITH THE EVOLVING UPPER CLOSED LOW. ...PARTS OF AZ AND UT EWD INTO WRN TX... AS UPPER LOW INTENSIFIES ACROSS THE SWRN STATES...STEEPENING MID-LEVEL LAPSE RATES SHOULD RESULT IN SUFFICIENT INSTABILITY FOR SHOWERS AND ISOLATED THUNDERSTORMS -- PARTICULARLY DURING THE SECOND HALF OF THE PERIOD. OVERNIGHT...LOW-LEVEL JET IS FORECAST TO DEVELOP ACROSS W TX AND INTO ERN NM IN RESPONSE TO SLOW EWD MOVEMENT OF THE UPPER FEATURE. RESULTING LOW-LEVEL WARM/MOIST ADVECTION MAY ALLOW A FEW THUNDERSTORMS TO DEVELOP AS FAR E AS THE TX PANHANDLE/S PLAINS/TRANSPECOS REGION THROUGH 19/12Z. ..GOSS.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 12:50:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 07:50:54 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181251 SWODY1 SPC AC 181249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0649 AM CST MON DEC 18 2006 VALID 181300Z - 191200Z ...NO SVR TSTM AREAS FORECAST... MORNING WATER VAPOR LOOPS AND MODEL GUIDANCE INDICATE LARGE POSITIVELY TILTED UPPER TROUGH FROM THE GREAT BASIN INTO SOUTHERN CA. THE PRIMARY VORT MAX OF THIS TROUGH WILL ROTATE EASTWARD TODAY/TONIGHT INTO THE DESERT SOUTHWEST. LARGE SCALE FORCING FOR ASCENT WILL INCREASE FROM PARTS OF UT/AZ EASTWARD INTO WEST TX MAINLY AFTER 00Z...RESULTING IN AN EXPANDING AREA OF SHOWERY PRECIPITATION. FORECAST SOUNDINGS SHOW ONLY WEAK CAPE VALUES /AOB 250 J/KG/ AND MARGINAL LAPSE RATES. THIS WILL LIMIT LIGHTNING POTENTIAL TO THE MOST ORGANIZED/VIGOROUS DEEP CONVECTION. POTENTIAL FOR SEVERE STORMS APPEARS LOW. ..HART.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 16:04:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 11:04:38 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181605 SWODY1 SPC AC 181603 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1003 AM CST MON DEC 18 2006 VALID 181630Z - 191200Z ...NO SVR TSTM AREAS FORECAST... PART OF A BROAD POSITIVE TILT UPPER TROUGH OVER THE WESTERN THIRD OF THE COUNTRY...WATER VAPOR IMAGERY AND 12Z UPPER AIR DIAGNOSTICS FEATURE A CLOSED UPPER LOW CENTERED OVER SOUTHERN CA. THIS FEATURE WILL SLOWLY MIGRATE EASTWARD ACROSS THE LOWER CO RIVER VALLEY/SOUTHWEST DESERTS INTO EARLY TUESDAY...WITH LARGE SCALE FORCING FOR ASCENT INCREASING/SPREADING EASTWARD ACROSS THE FOUR CORNERS AREA INTO THE SOUTHERN PLAINS THROUGH THE PERIOD. WEAK CONVECTIVE INSTABILITY AND MARGINAL LAPSE RATES WILL SUPPORT A POTENTIAL FOR ISOLATED LIGHTNING STRIKES ACROSS PORTIONS OF THE FOUR CORNERS INTO SOUTHWEST/FAR WEST TX...MAINLY LATE THIS AFTERNOON/TONIGHT. FARTHER EAST...PRESENCE OF UPPER RIDGE AND MARGINAL BUOYANCY/SHALLOW NATURE OF THE CONVECTION SHOULD LIMIT CG LIGHTNING POTENTIAL OVER THE REMAINDER OF THE SOUTHERN PLAINS INTO THE ARKLATEX. ..GUYER/THOMPSON.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 20:01:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 15:01:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 182002 SWODY1 SPC AC 182000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0200 PM CST MON DEC 18 2006 VALID 182000Z - 191200Z ...NO SVR TSTM AREAS FORECAST... COLD UPPER LOW THIS AFTERNOON LOCATED VICINITY CA/BAJA CA BORDER IS EXPECTED TO DRIFT SLOWLY EWD INTO SWRN AZ BY 12Z TUE. LARGE SCALE ASCENT AND ASSOCIATED PRECIPITATION WILL BE ON THE INCREASE ERN AZ INTO NM THRU TONIGHT AS 90KT MID LEVEL JET MAX CROSSING NRN BAJA HEADS TOWARD SWRN NM. AVAILABLE INSTABILITY TO SUPPORT CONVECTION E OF UPPER LOW REMAINS LIMITED...BUT WITH CONTINUED HEATING AND STEEPENING OF MID LEVEL LAPSE RATES A FEW THUNDERSTORMS EXPECTED HIGHER TERRAIN ERN AZ/WRN NM. TONIGHT ADDITIONAL ELEVATED WEAK CONVECTION...ISOLATED LIGHTNING...LIKELY WILL DEVELOP INTO ERN NM AND FAR W TX ABOVE THE SHALLOW COLD DOME WITH APPROACH OF THE UPPER JET AND SOME MID LEVEL COOLING. ..HALES.. 12/18/2006  From swody1 at goshenarc.org Tue Dec 19 00:40:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 19:40:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190041 SWODY1 SPC AC 190039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST MON DEC 18 2006 VALID 190100Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH UPPER LOW NOW CENTERED OVER SRN CA/NRN BAJA CA WILL CONTINUE TO PROVIDE MARGINAL INSTABILITY ACROSS THE FOUR CORNERS REGION. AS A RESULT...SHOWERS AND PERHAPS A FEW SPORADIC/EMBEDDED LIGHTNING STRIKES WILL CONTINUE THROUGH THE END OF THE PERIOD ACROSS PARTS OF THE SWRN CONUS. MEANWHILE...INCREASING WARM/MOIST ADVECTION IS FORECAST ACROSS W TX/ERN NM...AS ELY/SELY LOW-LEVEL JET STRENGTHENS AHEAD OF UPPER LOW. THIS MAY YIELD MARGINAL BUT SUFFICIENT CAPE FOR A FEW LIGHTNING STRIKES WITHIN LARGER AREA OF SHALLOWER CONVECTION. ..GOSS.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 05:55:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 00:55:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190555 SWODY1 SPC AC 190553 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1153 PM CST MON DEC 18 2006 VALID 191200Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MAIN UPPER FEATURE OF INTEREST ACROSS THE CONUS THIS PERIOD WILL BE THE SWRN U.S. CLOSED LOW -- INITIALLY FORECAST TO BE CENTERED OVER SRN CA/WRN AZ/NWRN MEXICO. THE LOW IS FORECAST TO PROGRESS EWD THROUGH THE PERIOD...REACHING ERN NM BY 20/12Z. IN RESPONSE TO THIS FEATURE...AN INVERTED SURFACE TROUGH IS EXPECTED TO EVOLVE ACROSS W TX AND WRN OK THROUGH THE END OF THE PERIOD. ...ERN AZ/THE FOUR CORNERS EWD INTO SRN KS/OK/TX... WIDESPREAD SHOWERS AND SCATTERED TO ISOLATED THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD -- INVOF UPPER COLD POOL OVER THE SWRN U.S. AS WELL AS WITHIN WARM ADVECTION REGIME FURTHER E INTO THE SRN HIGH PLAINS. THIS GENERAL SCENARIO WILL CONTINUE/SHIFT SLOWLY EWD WITH TIME...WITH SHOWERS AND SPORADIC LIGHTNING STRIKES ACROSS THE SRN ROCKIES/SWRN U.S. AND MORE WIDESPREAD THUNDERSTORMS SHIFTING ACROSS TX AND OK THROUGH THE END OF THE PERIOD. DEEP-LAYER WIND FIELD WILL INCREASE ACROSS THE SRN PLAINS DURING THE SECOND HALF OF THE PERIOD...AS 80 KT MID-LEVEL JET SPREADS EWD ATOP STRENGTHENING NOCTURNAL LOW-LEVEL JET. HOWEVER...VERY WEAK LAPSE RATES ARE FORECAST ACROSS THE ENTIRE REGION...WHICH WILL GREATLY LIMIT AVAILABLE INSTABILITY. THEREFORE...ANY SEVERE THREAT APPEARS TO BE MINIMAL ATTM. ..GOSS.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 12:50:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 07:50:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191251 SWODY1 SPC AC 191248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0648 AM CST TUE DEC 19 2006 VALID 191300Z - 201200Z ...NO SVR TSTM AREAS FORECAST... LARGE/DEEP UPPER LOW OVER AZ/CA WILL TRACK SLOWLY EASTWARD TODAY INTO NM. MEANWHILE...FORCING FOR UPWARD VERTICAL MOTION WILL OVERSPREAD MUCH OF THE SOUTHERN PLAINS STATES...HELPING TO CREATE A LARGE PRECIPITATION SHIELD ACROSS THE REGION. CLOUD COVER AND WEAK LAPSE RATES WILL SUPPRESS CAPE VALUES TO BELOW 500 J/KG. THIS MAY BE ENOUGH FOR ISOLATED THUNDERSTORMS THROUGHOUT THE FOUR CORNERS REGION INTO PARTS OF TX/OK/KS. STRONG LINEAR FORCING AND INCREASING WIND FIELDS ALOFT MAY SUPPORT A RISK MORE ORGANIZED THUNDERSTORM ACTIVITY OVER TX LATE TONIGHT. HOWEVER...SEVERE THREAT APPEARS TOO LOW TO WARRANT PROBABILITIES AT THIS TIME. ..HART.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 16:29:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 11:29:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191629 SWODY1 SPC AC 191627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST TUE DEC 19 2006 VALID 191630Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SRN ROCKIES AND SRN PLAINS THROUGH TONIGHT... A LARGE CLOSED LOW OVER WRN AZ WILL MOVE EWD INTO NM BY TONIGHT AS A SPEED MAX ROTATES AROUND THE S/SE SIDE OF THE UPPER LOW /OVER NW MEXICO/...AND UPSTREAM HEIGHTS FALL IN ADVANCE OF A SMALL WAVE NEAR 42 N AND 130 W. ONE PRONOUNCED BELT OF ASCENT COINCIDES WITH THE DEEP BAROCLINIC ZONE OVER WRN NM...WHILE TO THE EAST A BROAD REGION OF ASCENT RELATED TO WAA IS EXPECTED TO PERSIST INTO TONIGHT OVER THE SRN PLAINS. REGIONAL 12Z SOUNDINGS SHOW WEAK BUOYANCY /MUCAPE OF 100-400 J/KG/ IN A SWATH FROM THE MIDDLE RIO GRANDE VALLEY NWD OVER THE TX/NM HIGH PLAINS. THIS INSTABILITY...COMBINED WITH THE WAA TODAY AND DIFFERENTIAL CVA DOWNSTREAM FROM THE MID LEVEL LOW BY TONIGHT...WILL SUPPORT A GRADUAL EWD SPREAD OF /PRIMARILY/ ELEVATED THUNDERSTORMS FROM NM/TX PANHANDLE INTO CENTRAL/NW TX...WRN OK...AND SW KS THROUGH TONIGHT. THE PRESENCE OF RATHER POOR LAPSE RATES AND WIDESPREAD CLOUDS WITHIN THE WARM SECTOR ACROSS S CENTRAL TX WILL TEND TO LIMIT ADDITIONAL DESTABILIZATION AND ANY ASSOCIATED SEVERE STORM THREAT THROUGH TONIGHT. ..THOMPSON.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 19:49:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 14:49:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191949 SWODY1 SPC AC 191947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CST TUE DEC 19 2006 VALID 192000Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SRN ROCKIES INTO THE SRN PLAINS... BROAD AREA OF NON-SEVERE THUNDERSTORMS WILL CONTINUE TO EXPAND ACROSS THE REGION AHEAD OF SLOW MOVING UPPER LOW NOW MOVING ACROSS AZ. LEADING AREA OF ELEVATED THUNDERSTORMS OVER THE SRN HIGH PLAINS ATTM APPEARS ASSOCIATED WITH BROAD LOW LEVEL WAA WITHIN MID LEVEL MOISTURE PLUME WELL AHEAD OF APPROACHING SYSTEM. THIS ACTIVITY WILL LIKELY EXPAND NNEWD THIS EVENING...WITH ANOTHER BATCH OF MOIST CONVECTION AND THUNDERSTORMS DEVELOPING NEARER THE MID/UPPER LEVEL SYSTEM WHICH WILL LIKEWISE SHIFT ENEWD OVERNIGHT. FORECAST SOUNDINGS CONTINUE TO INDICATE MARGINAL INSTABILITY WITH ELEVATED PARCELS...SUGGESTING EMBEDDED THUNDERSTORMS WILL PERSIST. ..EVANS.. 12/19/2006  From swody1 at goshenarc.org Wed Dec 20 00:30:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 19:30:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200031 SWODY1 SPC AC 200029 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0629 PM CST TUE DEC 19 2006 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW NOW CENTERED OVER AZ WILL CONTINUE MOVING EWD INTO NM THROUGH THE END OF THE PERIOD. WIDESPREAD PRECIPITATION WITH EMBEDDED THUNDERSTORMS WILL PERSIST...FROM THE UPPER LOW CENTER EWD INTO THE CENTRAL AND SRN PLAINS. THOUGH MINIMAL INSTABILITY WILL PRECLUDE ANY APPRECIABLE SEVERE THREAT...EXPECT AN INCREASE IN THUNDERSTORM COVERAGE FROM SERN NM EWD ACROSS TX/OK AS LOW-LEVEL JET AND ASSOCIATED WARM ADVECTION INCREASE OVERNIGHT. ELSEWHERE...LACK OF INSTABILITY ACROSS THE REMAINDER OF THE CONUS IS FORECAST TO HINDER ANY POTENTIAL FOR DEEP MOIST CONVECTION. ..GOSS.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 05:48:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 00:48:47 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200549 SWODY1 SPC AC 200547 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1147 PM CST TUE DEC 19 2006 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THOUGH A MID-LEVEL SHORT-WAVE TROUGH IN THE NRN STREAM WILL AFFECT THE PAC NW AND A SECOND WILL CROSS THE GREAT LAKES/NEW ENGLAND...MAIN FEATURE WITH RESPECT TO DEEP MOIST CONVECTION WILL BE THE UPPER LOW MOVING INTO THE CENTRAL CONUS. THIS FEATURE...INITIALLY FORECAST OVER NM...IS EXPECTED TO MOVE ENEWD TO SWRN KS/THE TX AND OK PANHANDLES BY 21/12Z. AT THE SURFACE...LOW PRESSURE CENTER IS FORECAST TO LINGER OVER THE WRN KS/WRN OK REGION...WHILE TRAILING FRONT SHIFTS EWD ACROSS TX/OK THROUGH THE DAY...AND INTO THE LOWER MS VALLEY REGION BY THE END OF THE PERIOD. ...SERN TX INTO LA... SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOULD BE ONGOING ACROSS THIS REGION AT THE START OF THE PERIOD...WITHIN WEAK WARM ADVECTION REGIME. THOUGH BOUNDARY-LAYER AIRMASS WILL MOISTEN INTO LA AS SURFACE FLOW VEERS WITH TIME AHEAD OF APPROACHING SURFACE BOUNDARY...WEAK LAPSE RATES WILL CONTINUE TO LIMIT THE POTENTIAL FOR DESTABILIZATION. ADDITIONALLY...STRONGER DEEP-LAYER WIND FIELD IS FORECAST TO REMAIN NW OF THE WRN GULF COAST REGION...WITH MID-LEVEL JET CORE FORECAST TO REMAIN ACROSS N TX/OK THROUGH THE PERIOD. NONETHELESS...STORMS SHOULD BECOME MORE NUMEROUS THROUGH THE SECOND HALF OF THE PERIOD AS SURFACE BOUNDARY APPROACHES. LIMITED INSTABILITY/WEAK LAPSE RATES WILL LIMIT UPDRAFT INTENSITY...AND SO LITTLE HAIL POTENTIAL AND ONLY A MARGINAL WIND THREAT IS INDICATED. ALSO...WITH DEWPOINTS FORECAST IN THE MID 60S ACROSS SERN TX AND INTO MUCH OF LA AND MODERATE SHEAR EXPECTED IN THE 0-1 KM LAYER...AN ISOLATED TORNADO CANNOT BE RULED OUT. HOWEVER...OVERALL SEVERE POTENTIAL SHOULD REMAIN LOW/BELOW SLIGHT RISK THRESHOLDS THROUGH THE PERIOD. ..GOSS.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 12:35:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 07:35:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201235 SWODY1 SPC AC 201233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 AM CST WED DEC 20 2006 VALID 201300Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER MS VALLEY... MORNING SATELLITE LOOPS SHOW A DEEP UPPER LOW OVER NM. THIS SYSTEM WILL MOVE NORTHEASTWARD INTO PARTS OF WESTERN KS AND THE OK PANHANDLE BY EVENING. BAND OF 90-110 KNOT MID LEVEL WINDS WILL PUNCH EASTWARD ACROSS TX...WITH PRIMARY SURFACE COLD FRONT ALSO SURGING EASTWARD INTO EAST TX BY 21/00Z. STRONG SOUTHERLY LOW LEVEL WINDS AHEAD OF FRONT WILL TRANSPORT GULF MOISTURE NORTHWARD INTO EAST TX AND MUCH OF AR/LA/MS WITH DEWPOINTS RISING INTO THE MID 60S ACROSS THIS AREA OVERNIGHT. FORECAST SOUNDINGS SHOW WEAK LAPSE RATES AND ONLY MARGINAL CAPE VALUES. NEVERTHELESS...LARGE SCALE FORCING FOR ASCENT AND AMPLE LOW/MID LEVEL MOISTURE WILL AID IN THE DEVELOPMENT OF WIDESPREAD SHOWERS AND OCCASIONAL THUNDERSTORMS. STRENGTH OF WIND FIELDS SUGGEST A POTENTIAL OF ISOLATED THUNDERSTORM INTENSIFICATION AND A MARGINAL SEVERE THREAT. DAMAGING WINDS OR PERHAPS A TORNADO APPEAR TO BE THE MAIN CONCERNS. ...WESTERN WA... COLD TEMPERATURES ALOFT ASSOCIATED WITH THE NEXT UPPER TROUGH APPROACHING THE PACIFIC NORTHWEST COAST WILL LIKELY RESULT IN ISOLATED LIGHTNING STRIKES LATE TONIGHT OFF THE WA COAST. PRESENT INDICATIONS ARE THAT THREAT WILL NOT MOVE INLAND UNTIL THURSDAY. ..HART.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 16:31:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 11:31:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201632 SWODY1 SPC AC 201630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1030 AM CST WED DEC 20 2006 VALID 201630Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... DEEP MID LEVEL CLOSED LOW OVER NE NM THIS MORNING WILL MOVE SLOWLY ENEWD OVER THE SRN PLAINS THROUGH EARLY THURSDAY. AT THE SURFACE...AN OCCLUDED LOW INVOF NE NM WILL GRADUALLY FILL OVER THE OK PANHANDLE BY THIS EVENING...WHILE A SURFACE COLD FRONT MOVES EWD ACROSS ERN OK/TX. REGIONAL SOUNDINGS SHOW SOME WEAK ELEVATED INSTABILITY AS FAR N AS KS...AS WELL AS RATHER MARGINAL SURFACE-BASED INSTABILITY IN THE WARM SECTOR FARTHER S FROM SE OK INTO SE TX. VERTICAL SHEAR AND FORCING FOR ASCENT WILL REMAIN STRONGER FROM E TX NWD...WHILE THE SOMEWHAT STRONGER INSTABILITY WILL BE CONFINED MORE TO SE TX AND SRN LA BY TONIGHT. GIVEN THE POOR PHASING BETWEEN THE UNSTABLE WARM SECTOR AND THE FORCING/VERTICAL SHEAR...ANY SEVERE STORM THREAT WILL REMAIN RATHER MARGINAL ACROSS SE TX AND SRN LA THROUGH TONIGHT. OTHERWISE...A SHORTWAVE TROUGH NEAR 44 N AND 136 W WILL APPROACH NW WA BY EARLY THURSDAY. OCEANIC LIGHTNING DATA SHOW A FEW STRIKES WITH THIS SYSTEM...BUT ANY THUNDERSTORM THREAT SHOULD REMAIN OFFSHORE THIS FORECAST PERIOD. ..THOMPSON.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 19:44:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 14:44:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201945 SWODY1 SPC AC 201942 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0142 PM CST WED DEC 20 2006 VALID 202000Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...E TX TO LOWER MS VALLEY... COLD FRONT WILL CONTINUE TO SPREAD EWD THIS AFTERNOON THROUGH ERN OK/TX TOWARD THE MS VALLEY...AND SHOULD EXTEND FROM THE MID MS VALLEY SWWD THROUGH LA TO OFF THE TX GULF COAST BY 12Z THURSDAY...AS ASSOCIATED UPPER LOW MOVES SLOWLY TOWARD THE CENTRAL/SRN PLAINS. DESPITE MOISTURE ADVECTION INTO THE LOWER MS VALLEY THIS FORECAST PERIOD...WEAK LAPSE RATES ARE EXPECTED TO MAINTAIN MARGINAL INSTABILITY...AT BEST...FOR TSTM DEVELOPMENT ALONG AND AHEAD OF THE COLD FRONT. ALTHOUGH INSTABILITY IS GREATER SWD ALONG THE TX COASTAL PLAIN...THE LACK OF STRONGER LARGE SCALE FORCING SHOULD CONTINUE TO LIMIT THE POTENTIAL FOR DEEP CONVECTION IN THAT REGION. A WEAK SRN STREAM IMPULSE MOVING NEWD ACROSS THE LOWER MS VALLEY AT THIS TIME IS LIKELY AIDING IN THE RECENT INCREASE IN TSTM ACTIVITY JUST OFF THE LA COAST. THIS ACTIVITY IS LOCATED GENERALLY ALONG AND NORTH OF A SURFACE BOUNDARY WHICH EXTENDED FROM THE UPPER TX COAST EWD INTO THE FAR NRN GULF OF MEXICO. SHORT TERM MODELS SUGGEST THE WRN EXTENT OF THIS BOUNDARY MAY MOVE INLAND ACROSS FAR SE TX AND SW LA...THUS INCREASING THE POTENTIAL FOR SURFACE BASED STORMS LATER TONIGHT. EFFECTIVE BULK SHEAR AND LOW LEVEL SHEAR VALUES WILL BE SUFFICIENT FOR ROTATING TSTMS WITH AN ISOLATED TORNADO THREAT. HOWEVER...WITH ONLY WEAK INSTABILITY AND THE LACK OF STRONGER FORCING ALOFT LATER IN THE FORECAST PERIOD...WILL MAINTAIN LOW SEVERE PROBABILITIES WITH THIS OUTLOOK. ...WRN WA... PACIFIC TROUGH...CURRENTLY LOCATED NEAR 44 N 134 W...WILL APPROACH NW WA AND BRITISH COLUMBIA LATE IN THE FORECAST PERIOD. COLD MID LEVEL TEMPERATURES WITH THIS SYSTEM AND INCREASING ASCENT SHOULD MAINTAIN AREA OF TSTMS WITH TROUGH...BUT ANY TSTM THREAT SHOULD REMAIN OFFSHORE THROUGH 12Z THURSDAY. ..PETERS.. 12/20/2006  From swody1 at goshenarc.org Thu Dec 21 00:36:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 19:36:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210036 SWODY1 SPC AC 210034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST WED DEC 20 2006 VALID 210100Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER/MID MS VALLEY... NEAR SURFACE BASED CONVECTION WILL REMAIN CONFINED TO EXTREME SERN TX AND SRN LA TONIGHT AS MARINE LAYER STRUGGLES TO MOVE VERY FAR INLAND. EVEN SO...PARCEL BUOYANCY WILL PROVE SOMEWHAT LIMITED AS LAPSE RATES ARE MARGINAL AND MOIST. 00Z SOUNDING FROM LCH SUGGESTS CONVECTION IS ROOTED NEAR 950 MB...WHILE MARGINAL LOW LEVEL SHEAR AT SRN EXTENT OF WARM CONVEYOR SEEMS LESS THAN IDEAL FOR MEANINGFUL ORGANIZED SEVERE STORMS. AT THIS TIME IT APPEARS DEEP LAYER SHEAR IS ADEQUATE FOR DEEP ROTATION...BUT OVERALL SEVERE THREAT SHOULD REMAIN QUITE ISOLATED...HENCE LOW PROBABILITIES FOR GUSTY WINDS OR PERHAPS A BRIEF WEAK TORNADO. FARTHER NORTH...WIDESPREAD ELEVATED CONVECTION WITHIN ZONE OF STRONGER FORCING SHOULD CONTINUE THE REST OF THE PERIOD FROM AR INTO MO. THIS ACTIVITY IS LARGELY DRIVEN BY STRONG ASCENT ACTING ON WEAK INSTABILITY WITHIN 700-400MB LAYER. ..DARROW.. 12/21/2006  From swody1 at goshenarc.org Sun Dec 31 16:12:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 31 Dec 2006 11:12:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311616 SWODY1 SPC AC 311614 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1014 AM CST SUN DEC 31 2006 VALID 311630Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SOUTHEAST STATES AND TN VALLEY... SATELLITE IMAGERY SHOWS DEEP UPPER LOW OVER KS/MO LIFTING NORTHEASTWARD INTO THE MIDWEST. BAND OF 90-110 KNOT SOUTHWESTERLY MID LEVEL WINDS WILL ROTATE ACROSS THE LOWER/MID MS VALLEY TODAY...WHILE 40-60 KNOT SOUTHERLY LOW LEVEL JET WILL EXTEND ACROSS THE GULF COAST STATES AND TN VALLEY. RESULTING VERTICAL SHEAR PROFILE WOULD BE VERY FAVORABLE FOR ORGANIZED/ROTATION STORMS IF SUFFICIENT INSTABILITY WERE PRESENT. HOWEVER...SURFACE DEWPOINTS ARE BELOW 60F FROM NORTHERN AL NORTHWARD WHICH SHOULD LIMIT AFTERNOON MLCAPE VALUES TO BELOW 300 J/KG AND PRECLUDE AN ORGANIZED SEVERE THREAT. HIGHER DEWPOINTS VALUES /IN THE MID 60S/ LIE ACROSS PARTS OF AL/FL/GA...WHERE MLCAPE VALUES MAY APPROACH 500 J/KG THIS AFTERNOON. HOWEVER...FORECAST SOUNDINGS SHOW WEAK LOW/MID LEVEL LAPSE RATES AND VEERING LOW LEVEL WINDS WITH TIME. EMBEDDED STORMS IN THIS AREA WILL BE CAPABLE OF GUSTY WINDS OR A BRIEF TORNADO. HOWEVER...OVERALL SEVERE THREAT APPEARS QUITE LIMITED TODAY. ...MID/UPPER MS VALLEY... DRY SLOT IS NOTED ON WATER VAPOR IMAGERY ROTATING AROUND UPPER LOW INTO THE MID MS VALLEY. CLOUDS ARE ERODING IN THIS AREA...WHICH SHOULD RESULT IN A FEW HOURS OF DAYTIME HEATING THIS AFTERNOON ACROSS PARTS OF NORTHERN IL/IND. STEEPENING LAPSE RATES BENEATH MID LEVEL COLD POOL...COMBINED WITH RESIDUAL LOW LEVEL MOISTURE...IS EXPECTED TO PROVIDE AFTERNOON MLCAPE VALUES AROUND 500 J/KG. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE FORECAST IN THIS AREA...LIFTING NORTHWARD INTO PARTS OF WI/MI DURING THE EVENING. THERMODYNAMIC PROFILES ARE QUITE COLD...SUGGESTING THE POTENTIAL FOR SMALL HAIL IN STRONGER CELLS. ..HART.. 12/31/2006  From swody1 at goshenarc.org Sun Dec 31 19:47:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 31 Dec 2006 14:47:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311951 SWODY1 SPC AC 311949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SUN DEC 31 2006 VALID 312000Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SE GA AND NRN FL... AT THE SFC...A COLD FRONT IS LOCATED FROM MIDDLE TN EXTENDING SWD ACROSS CNTRL AL. A LINE OF THUNDERSTORMS EXISTS WELL AHEAD OF THE BOUNDARY IN SW GA AND ACROSS THE ERN FL PANHANDLE. SFC DEWPOINTS AHEAD OF THE LINE RANGE FROM THE MID 60S F TO THE LOWER 70S F AND OBJECTIVE ANALYSIS SHOWS AN AXIS OF WEAK INSTABILITY PRESENT ACROSS THE NRN PENINSULA OF FL INTO SRN AND ERN GA. THE LINE SHOULD REMAIN SOMEWHAT ORGANIZED MOVING EWD INTO THE INSTABILITY AXIS LATE THIS AFTERNOON. IN ADDITION...OBJECTIVE ANALYSIS CURRENTLY SHOWS A SMALL 50 KT MID-LEVEL JET LOCATED BEHIND THE LINE WHICH IS POSSIBLY ASSOCIATED WITH A SUBTLE SHORTWAVE TROUGH. AS THIS FEATURE DRIFTS EWD THIS AFTERNOON...SHEAR PROFILES ALONG THE LINE MAY BE JUST STRONG ENOUGH FOR MARGINALLY SEVERE THUNDERSTORMS CAPABLE OF ISOLATED WIND DAMAGE. ...ERN IL/IND/SW LOWER MI... LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL LOW LIFTING NEWD ACROSS MO TOWARD THE LOWER OH VALLEY. VERY STRONG LARGE-SCALE ASCENT EXISTS IN A BROAD ZONE AHEAD OF THE UPPER-LOW. THIS ALONG WITH STEEP LAPSE RATES WILL PROMOTE THE DEVELOPMENT OF SCATTERED THUNDERSTORMS LATE THIS AFTERNOON FROM THE CHICAGO IL AREA EXTENDING SEWD TO THE VICINITY OF INDIANAPOLIS IN. THE STRONGLY SHEARED ENVIRONMENT ALONG WITH COLD TEMPS ALOFT ASSOCIATED WITH THE UPPER-LOW COULD RESULT IN A FEW STORMS CAPABLE OF PRODUCING HAIL MAINLY NEAR OR JUST AFTER PEAK HEATING. ..BROYLES.. 12/31/2006  From swody1 at goshenarc.org Fri Dec 1 00:53:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 19:53:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010055 SWODY1 SPC AC 010053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 PM CST THU NOV 30 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE SERN U.S. THROUGH THE TN VALLEY INTO SRN PARTS OF THE OH VALLEY... ...KY THROUGH TN VALLEY AND PORTIONS OF THE SERN STATES... ARCTIC FRONT EXTENDS FROM THE LOWER GREAT LAKES SWWD THROUGH OH TO A SURFACE LOW NEAR MEMPHIS. THE FRONT THEN EXTENDS SWD THROUGH WRN MS AND SERN LA. THE LOW WILL DEEPEN FURTHER AND LIFT NEWD TONIGHT AS ASCENT WITHIN DIVERGENT EXIT REGION OF CYCLONICALLY CURVED UPPER JET OVERTAKES THE FRONT. AS THIS OCCURS...THE PORTION OF FRONT S OF THE LOW WILL SHIFT MORE RAPIDLY EWD THROUGH THE TN VALLEY AND SERN STATES. AS THE LOW DEEPENS...THE LOW LEVEL JET AND FRONTOGENETIC FORCING WILL INCREASE THIS EVENING...ESPECIALLY OVER THE TN VALLEY INTO KY. PRE-FRONTAL WARM SECTOR IS CHARACTERIZED BY BOUNDARY LAYER DEWPOINTS FROM THE UPPER 60S NEAR THE COAST TO NEAR 60 IN SRN PARTS OF THE OH VALLEY. HOWEVER...POOR MID LEVEL LAPSE RATES AND LIMITED DAYTIME HEATING HAVE RESULTED IN VERY WEAK INSTABILITY WITH MUCAPE GENERALLY FROM 100 TO 300 J/KG. THE 00Z JAN SOUNDING SHOWS ONLY A SLIVER OF CAPE IN THE 700-500 MB LAYER. A PRE-FRONTAL CONVECTIVE BAND EXTENDS FROM MIDDLE TN SWD THROUGH SERN MS. FARTHER W A MORE STRONGLY FORCED BAND EXTENDS ALONG THE FRONT FROM EXTREME WRN TN SWD THROUGH WRN MS. STRONG LINEAR FORCING MAY CONTINUE TO SUPPORT A LINE OF LOW TOPPED CONVECTION WITH LITTLE LIGHTNING ALONG THE FRONT AS IT MOVES EWD THROUGH THE EVENING AND OVERNIGHT. STRENGTHENING LOW LEVEL WIND PROFILES WITH 60+ KT JUST OFF THE SURFACE WILL EXIST IN VICINITY OF THIS CONVECTION...AND SOME OF THIS MOMENTUM COULD BE TRANSPORTED DOWN TO THE SURFACE WITHIN THE HEAVIER SHOWERS...PROMOTING A THREAT FOR ISOLATED DAMAGING WIND. LARGE LOW LEVEL HODOGRAPHS AND STRONG CLOUD LAYER SHEAR WOULD ALSO LEND SOME SUPPORT FOR LOW TOPPED SUPERCELLS. HOWEVER...THE WEAK INSTABILITY WILL CONTINUE TO SERVE AS AN OVERALL LIMITING FACTOR FOR A MORE ROBUST SEVERE THREAT. ..DIAL.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 05:48:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 00:48:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010550 SWODY1 SPC AC 010548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST THU NOV 30 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS FOR PORTIONS OF MD...PA AND NY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NC THROUGH THE MID ATLANTIC...NERN U.S. AND ERN PORTIONS OF THE OH VALLEY... ...SYNOPSIS... SHORTWAVE TROUGH OVER THE LOWER MS VALLEY THIS EVENING WILL EJECT NEWD INTO THE LOWER GREAT LAKES AND NERN U.S. BY FRIDAY AFTERNOON. ATTENDANT SURFACE CYCLONE CURRENTLY OVER WRN KY WILL OCCLUDE AS IT LIFTS NWD INTO THE GREAT LAKES BY LATE MORNING. HOWEVER...SECONDARY CYCLOGENESIS IS EXPECTED FARTHER EAST ACROSS NY AS STRONG FORCING FOR ASCENT WITHIN DIVERGENT EXIT REGION OF CYCLONIC UPPER JET LIFTS NEWD INTO THIS REGION. ARCTIC FRONT CURRENTLY EXTENDS FROM THE UPPER GREAT LAKES AREA SWWD TO A SURFACE LOW NEAR WRN KY THEN SWD INTO THE CNTRL GULF AREA. NRN PORTION OF THIS BOUNDARY WILL MOVE LITTLE DUE TO ACCELERATING SLY FLOW IN WARM SECTOR ACCOMPANYING CYCLOGENESIS. HOWEVER...SRN PORTION OF THIS BOUNDARY WILL CONTINUE EAST THROUGH THE SERN STATES...MID ATLANTIC AND NERN U.S. BEFORE MOVING OFFSHORE FRIDAY NIGHT. ...MID ATLANTIC THROUGH NERN STATES AND ERN PORTION OF OH VALLEY... LOW LEVEL JET WILL STRENGTHEN TO IN EXCESS OF 70 KT FROM NC INTO THE NERN U.S. AS SECONDARY CYCLONE DEEPENS OVER NY. LOW TO MID 60S BOUNDARY LAYER DEWPOINTS CURRENTLY RESIDE ACROSS VA AND THE CAROLINAS. THE STRENGTHENING SLY LOW LEVEL JET WILL CONTRIBUTE TO NWD ADVECTION OF THIS MOISTURE THROUGH FRIDAY. AS UPPER TROUGH EJECTS NEGATIVELY TILTED INTO THE NERN STATES...A MID LEVEL THERMAL TROUGH WILL SPREAD OVER A PORTION OF THE WARM SECTOR AND CONTRIBUTE TO SLIGHTLY BETTER MID LEVEL LAPSE RATES THAN IN THURSDAYS WARM SECTOR. PRE-FRONTAL MUCAPE AROUND 500 J/KG WILL BE POSSIBLE...ESPECIALLY IF POCKETS OF HEATING CAN DEVELOP. INSTABILITY COULD BE SLIGHTLY HIGHER WITHIN ZONE OF FORCED DEEP LAYER ASCENT ALONG SURFACE FRONT. CONVECTION WILL LIKELY BE ONGOING ALONG THE FRONT OVER PORTIONS OF THE OH VALLEY EARLY FRIDAY. STRENGTHENING LOW-MID LEVEL WIND FIELDS AND INCREASING ISALLOBARIC AND FRONTOGENETIC FORCING SHOULD MAINTAIN A FORCED LINE OF STORMS EWD THROUGH THE NERN STATES. THIS ACTIVITY WILL LIKELY STRENGTHEN AS THE ATMOSPHERE UNDERGOES FURTHER DESTABILIZATION DURING THE AFTERNOON. LOW LEVEL AND CLOUD LAYER SHEAR PROFILES WITH LARGE HODOGRAPHS WILL SUPPORT ORGANIZED STORMS INCLUDING LEWP/BOWS WITHIN THE LINE. A FEW SUPERCELL STRUCTURES WILL ALSO BE POSSIBLE ALONG THE LINE OR IF STORMS MANAGE TO DEVELOP AHEAD OF THE LINE. WITH THE LOW LEVEL JET STRENGTHENING TO 60+ KT JUST OFF THE SURFACE...POTENTIAL WILL EXIST FOR THIS MOMENTUM TO BE TRANSPORTED DOWN TO THE SURFACE AS FRONTAL CONVECTION SPREADS EWD. PRIMARY THREAT WILL BE DAMAGING WIND...BUT AN ISOLATED TORNADO OR TWO MAY ALSO BE POSSIBLE. GREATEST THREAT FOR SWATHS OF WIDESPREAD DAMAGING WIND IS EXPECTED IN MODERATE RISK AREA WITH MORE ISOLATED WIND POTENTIAL IN SLIGHT RISK REGION. ...NC... STRONGEST FORCING WILL LIFT N OF THIS REGION. THIS ALONG WITH MODEST LAPSE RATES AND INSTABILITY MAY SERVE TO LIMIT OVERALL SEVERE THREAT. HOWEVER...GIVEN STRENGTH OF LOW LEVEL WIND FIELDS...WILL MAINTAIN A THREAT FOR ISOLATED WIND DAMAGING WITH ANY CONVECTION DEVELOPING ALONG OR JUST AHEAD OF THE FRONT. ..DIAL.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 12:59:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 07:59:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011301 SWODY1 SPC AC 011259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST FRI DEC 01 2006 VALID 011300Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE MID ATLANTIC STATES AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM NC AND ERN OH INTO CNTRL NEW ENGLAND... ...SYNOPSIS... INTENSE SHORTWAVE TROUGH NOW OVER IL/IND EXPECTED TO CONTINUE ACCELERATING NEWD TODAY/TONIGHT AS IT ASSUMES AN INCREASINGLY NEGATIVE TILT. THE SYSTEM SHOULD BE CENTERED E OF TORONTO BY THIS EVENING AS ASSOCIATED SFC LOW MOVES RAPIDLY ENE FROM WRN OH TO N OF KALB. COLD FRONT TRAILING SSW FROM LOW SHOULD REACH THE NJ CST AND ERN NC BY 00Z SATURDAY. THE FRONT LIKELY WILL BE WELL OFF THE CST BY MIDNIGHT. ...UPR OH VLY/MID ATLANTIC/NERN STATES... LLJ WILL STRENGTHEN TO MORE THAN 70 KTS FROM NC INTO THE NERN U.S. LATER TODAY AS SFC LOW DEEPENS AND TRACKS ENE ACROSS NRN PA/UPSTATE NY. SEASONABLY RICH BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE UPR 50S TO MID 60S/ WILL SWEEP FARTHER NNE INTO THE DELAWARE AND HUDSON VLYS...AND INTO THE SRN HALF OF NEW ENGLAND. ACCELERATION OF NEGATIVE TILT UPR TROUGH WILL ENHANCE LARGE SCALE FORCING FOR ASCENT IN VERY STRONGLY SHEARED ENVIRONMENT ALONG/AHEAD OF SYSTEM COLD FRONT. COUPLED WITH INCREASING MOISTURE AND MODEST DIURNAL HEATING...SETUP MAY SUPPORT DEVELOPMENT AND/OR INTENSIFICATION OF NARROW...FAST-MOVING CONVECTIVE LINES/STORMS. WITH PRE-FRONTAL MUCAPE AROUND 500 J/KG...COMBINATION OF STRONG GRADIENT FLOW WITH CONVECTIVELY-ENHANCED WINDS COULD YIELD SCATTERED SWATHS OF DAMAGING WIND. ISOLATED TORNADOES WILL ALSO BE POSSIBLE...ESPECIALLY INVOF LINE BREAKS...GIVEN INTENSE LOW LEVEL SHEAR /0-1 KM SRH AOA 300 M2/S2/. WIND DAMAGE POTENTIAL SHOULD BE GREATEST ALONG AND JUST S OF MID LEVEL SPEED MAX FROM CNTRL/ERN PA INTO PARTS OF NY/NJ AND WRN/SRN NEW ENGLAND...WITH MORE ISOLATED WIND DAMAGE EXPECTED FARTHER S. ...NC/SRN VA... STRONGEST FORCING WILL LIFT N OF THIS REGION. THIS FACTOR...ALONG WITH MODEST INSTABILITY...SHOULD SERVE TO LIMIT OVERALL SEVERE THREAT. NEVERTHELESS...GIVEN STRENGTH OF LOW LEVEL WIND FIELD...A LOW PROBABILITY WILL EXIST FOR DAMAGING WIND WITH ANY SUSTAINED CONVECTION FORMING ALONG OR JUST AHEAD OF COLD FRONT. ..CORFIDI/KERR.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 16:29:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 11:29:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011631 SWODY1 SPC AC 011629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST FRI DEC 01 2006 VALID 011630Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS INTO PARTS OF THE MID ATLANTIC AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE PIEDMONT INTO THE NORTHEAST... ...PIEDMONT INTO THE MID ATLANTIC AND NORTHEAST... PAIR OF SURFACE LOWS WILL CONTINUE TO DEEPEN AHEAD OF INTENSE MID/UPPER LEVEL LOW NOW SPREADING TOWARDS ONTARIO. LEADING LOW CONTINUES ALONG EFFECTIVE COLD FRONT/WARM FRONT NOW NEAR LAKE ERIE. INTENSE PRESSURE FALLS ARE OCCURRING AHEAD OF THIS LOW...AND MORNING MODELS FORECAST THE LOW TO DEEPEN AND LIFT INTO NERN NY BY THE EARLY EVENING. THIS WILL SURGE LEADING COLD FRONT EWD ACROSS THE APPALACHIANS AND EXTEND FROM ERN NY SSWWD ACROSS WRN NJ AND THE CHESAPEAKE REGION BY 00Z...AND OFF THE COAST BY MIDNIGHT. ACCOMPANYING WARM FRONT...NOW WELL DEFINED ACROSS FAR SWRN NY INTO CENTRAL NEW ENGLAND...WILL LIFT QUICKLY NWD INTO SWRN/CENTRAL NY AND EVENTUALLY ACROSS ALL BUT NRN NEW ENGLAND LATER THIS EVENING. NARROW LINE OF DEEP MOIST CONVECTION HAS STEADILY INCREASED AND BECOME MORE ORGANIZED INTO FAR WRN PA ND NERN WV THIS MORNING. DESPITE THE LIMITED LAPSE RATES AHEAD OF THIS ACTIVITY...INTENSE DEEP ASCENT WILL FORCE A NARROW LINE OF INTENSE CONVECTION/THUNDERSTORMS EWD ACROSS MUCH OF THE CENTRAL APPALACHIANS INTO THE URBAN CORRIDOR FROM PARTS OF CENTRAL/ERN VA INTO THE HUDSON VALLEY/NEW ENGLAND THROUGH THE EARLY EVENING. AS THE AFTERNOON PROGRESSES...CLOUD TO GROUND LIGHTNING WILL LIKELY STEADILY INCREASE...AS WILL THE POTENTIAL FOR DAMAGING WINDS. VWP DATA FROM KCCX AND KPBZ AHEAD OF THE LINE INDICATE EXTREME WINDS /I.E. 50-60 KT SLYS/ JUST OFF THE SURFACE...WITH RESULTANT VERY LARGE HODOGRAPHS. THUS IT APPEARS WIND DAMAGE MAY BECOME QUITE PRONOUNCED/WIDESPREAD INTO THE MID AFTERNOON AND CONTINUE WELL INTO THE EARLY EVENING FROM PORTIONS OF CENTRAL PA/NRN MD INTO SWRN NEW ENGLAND/SERN NY. GIVEN THE MAGNITUDE OF LOW LEVEL SHEAR AND RELATIVELY HIGH BOUNDARY LAYER RH ...ISOLATED TORNADO THREAT WILL ACCOMPANY QUASI-LINEAR OR MORE DISCRETE STORMS. SEVERE THREAT WILL BECOME MORE CONDITIONAL FARTHER SOUTH ALONG THE FRONT /SOUTH OF THE DELMARVA REGION/ DUE TO RELATIVELY WEAKER ASCENT. HOWEVER...VERY IMPRESSIVE LOW LEVEL WIND PROFILES AND VERY WARM/MOIST BOUNDARY LAYER SHOULD SUPPORT A THREAT OF DAMAGING WINDS AND POSSIBLY TORNADOES. ..EVANS/CROSBIE.. 12/01/2006  From swody1 at goshenarc.org Fri Dec 1 19:50:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 14:50:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011952 SWODY1 SPC AC 011949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST FRI DEC 01 2006 VALID 012000Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS CENTRAL AND EASTERN PA...SOUTH CENTRAL AND SOUTHEASTERN NY AND NORTHWEST NJ... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN MID-ATLANTIC REGION INTO CNTRL/SRN NEW ENGLAND... ...MID-ATLANTIC INTO NY STATE AND CNTRL/SRN NEW ENGLAND... STRONG UPPER LOW CONTINUED TO MOVE NEWD THROUGH THE OH VLY AT MID-AFTN AND SHOULD MOVE INTO SERN CANADA TONIGHT. CYCLOGENESIS CONTINUES ACROSS WRN NY STATE AHEAD OF THE LOW. THIS LOW WILL MOVE INTO SRN QUE THIS EVENING. A WEAKER SUB-SYNOPTIC LOW MAY BE FORMING ACROSS CNTRL PA AS THE SRN AXIS OF LARGE SCALE HEIGHT FALLS SPREADS ACROSS THE APPALACHIANS. THIS FEATURE SHOULD MOVE INTO SCNTRL/SERN NY THIS EVENING AND INTO CNTRL NEW ENGLAND OVERNIGHT. A WARM MOIST BOUNDARY LAYER CONTINUED TO SPREAD NWD THROUGH THE REGION AHEAD OF THE UPPER SYSTEM. WARM FRONT SITUATED FROM THE WRN NY CYCLONE EWD INTO SRN NH WILL LIKELY MOVE A LITTLE FARTHER NWD...BUT IT APPEARS THAT EXTREME NRN SECTIONS OF NY-VT-NH AND MOST OF MAINE SHOULD REMAIN IN THE COLD AIR THE LONGEST...MITIGATING WIDESPREAD SVR WEATHER. FARTHER S...A SEGMENTED COLD FRONT EXISTS FROM SWRN NY ACROSS PA INTO THE CAROLINAS. INITIAL BAND OF TSTMS THAT PRODUCED DAMAGING WINDS ACROSS WRN PA HAD WEAKENED...BUT APPEARS TO BE STRENGTHENING AGAIN EAST OF THE MOUNTAINS. SFC ANALYSIS PLACES A LOW-LEVEL THERMAL RIDGE THROUGH ERN PA INTO SCNTRL NY WHERE TEMPERATURES HAVE CLIMBED TO NEAR 70 DEG F RESULTING IN RUC-DERIVED MLCAPES AROUND 500 J/KG. AS THE STRONGEST LARGE SCALE ASCENT SPREADS ACROSS THE REGION...THE STORMS MAY INTENSIFY AND EVOLVE MORE LINEARLY AS THEY TRANSLATE INTO ERN PA AND SCNTRL-SERN NY WITH BOWS/LEWPS. 55 KT 1KM FLOW WILL LIKELY BE BROUGHT TO THE SFC...AUGMENTING POTENTIAL FOR DAMAGING WINDS. FURTHERMORE...ISOLD TORNADOES WILL BE POSSIBLE... ESPECIALLY WITH ANY EMBEDDED SUPERCELL STRUCTURES THAT DEVELOP. FARTHER N...REMNANT BAND OF CONVECTION WILL LIKELY CONTINUE ACROSS CNTRL NY WITH POTENTIAL FOR MORE ISOLD DAMAGING WINDS. OVERNIGHT...PRIMARY LINE OF TSTMS SHOULD MOVE FROM THE NRN MID ATLANTIC REGION/SERN NY EWD ACROSS CNTRL/SRN NEW ENGLAND. SLY FLOW HAS BROUGHT A MARINE ENVIRONMENT NWD INTO MUCH OF SRN NEW ENGLAND. BUT...THE BOUNDARY LAYER SHOULD REMAIN SUFFICIENTLY TURBULENT TO MAINTAIN A SLGT RISK OF DAMAGING WINDS ACROSS THAT REGION OVERNIGHT. ..RACY.. 12/01/2006  From swody1 at goshenarc.org Sat Dec 2 00:40:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Dec 2006 19:40:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020042 SWODY1 SPC AC 020040 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 PM CST FRI DEC 01 2006 VALID 020100Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS NERN U.S.... ...NERN STATES THROUGH SRN NEW ENGLAND... STRONGLY FORCED SQUALL LINE FROM SRN NH SWD THROUGH NJ AND MD WILL CONTINUE RAPIDLY EWD AND OFFSHORE WITHIN THE NEXT FEW HOURS. WITH 80+ KT JUST OFF THE SURFACE...THREAT FOR DAMAGING WIND GUSTS WILL ACCOMPANY THE STRONGER STORMS WITHIN THE LINE. AS STORMS CONTINUE EAST...THEY WILL ENCOUNTER A BOUNDARY LAYER THAT IS MORE STABLE OVER SRN NEW ENGLAND DUE TO THE INFLUX OF COOLER MARINE AIR. AS A RESULT STORMS MAY BECOME A LITTLE LESS EFFICIENT TRANSPORTING STRONGER WINDS DOWN TO THE SURFACE AND UNDERGO GRADUAL WEAKENING. HOWEVER...AT LEAST ISOLATED DAMAGING WIND POTENTIAL IS EXPECTED TO PERSIST UNTIL ACTIVITY MOVES OFFSHORE. LARGE 0-2 KM HODOGRAPHS WILL CONTINUE TO SUPPORT POTENTIAL FOR LOW LEVEL MESOCYCLONES AND ISOLATED TORNADOES WITH ANY SUPERCELLS EMBEDDED WITHIN THE LINE. HOWEVER...TORNADO POTENTIAL SHOULD ALSO GRADUALLY DECREASE AS THE LINES MOVES EAST INTO A MORE STABLE BOUNDARY LAYER. ..DIAL.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 05:33:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 00:33:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020534 SWODY1 SPC AC 020532 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST FRI DEC 01 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE MODIFYING ARCTIC HIGH PRESSURE WILL PREVAIL OVER MUCH OF THE NATION WITH OFFSHORE FLOW OVER THE GULF. THIS WILL RESULT IN MOSTLY STABLE CONDITIONS AND LIMIT THUNDERSTORM POTENTIAL. SOME CONVECTION WILL BE POSSIBLE WITHIN ZONE OF WEAK ISENTROPIC ASCENT IN VICINITY OF STALLED FRONT ACROSS PARTS OF NRN FL AND SRN GA SATURDAY EVENING. HOWEVER...THE THERMODYNAMIC ENVIRONMENT WITH LIMITED INSTABILITY SUGGESTS ANY LIGHTING ACTIVITY SHOULD REMAIN ISOLATED. ..DIAL.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 12:53:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 07:53:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021255 SWODY1 SPC AC 021253 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 AM CST SAT DEC 02 2006 VALID 021300Z - 031200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD...SLOWLY PROGRESSIVE POSITIVE TILT UPR TROUGH WILL PREVAIL ACROSS THE LWR 48 THIS PERIOD. TWO IMPULSES IN WEAK SPLIT OVER THE WRN STATES AND SW CANADA ARE EXPECTED TO PHASE OVER THE CNTRL/SRN PLNS LATER IN THE PERIOD...LEADING TO SLIGHT RIDGING OVER S FL AND THE WRN ATLANTIC. TRAILING FRONT ASSOCIATED WITH SYSTEM THAT EXITED THE NERN U.S. LATE YESTERDAY SHOULD BECOME STATIONARY OVER CNTRL FL LATER TODAY/ TONIGHT. WEAK WARM ADVECTION WILL DEVELOP N OF THIS BOUNDARY ACROSS N FL/GA AND SC EARLY SUNDAY AS PHASING TROUGH AMPLIFIES OVER THE PLNS. WARM LAYER BETWEEN 700 AND 500 MB SUGGESTS THAT ANY ASSOCIATED CONVECTIVE DEVELOPMENT WILL REMAIN TOO SHALLOW FOR CHARGE SEPARATION/THUNDER. ISOLATED STORMS MAY...HOWEVER...OCCUR THROUGHOUT THE PERIOD OVER THE OFFSHORE WATERS INVOF THE FRONT... FROM OFF THE NC/SC CST SW INTO THE GULF OF MEXICO. IN THE NRN STREAM...A LIGHTNING STRIKE OR TWO MAY OCCUR THIS EVENING NEAR THE KEWEENAW PENINSULA OF MI AS VERY COLD AIR ALOFT AND WEAK LOW LEVEL CONVERGENCE FIELD ACCOMPANY SLOW MOVING UPR VORT NOW OVER NRN MN. ..CORFIDI/PETERS.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 15:56:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 10:56:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021557 SWODY1 SPC AC 021555 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0955 AM CST SAT DEC 02 2006 VALID 021630Z - 031200Z ...NO TSTM AREAS FORECAST... AIR MASS WILL REMAIN TOO STABLE FOR DEEP MOIST CONVECTION TODAY ACROSS THE CONUS. SHALLOW MOIST CONVECTION SHOULD OCCUR NEAR STALLED SURFACE FRONT ACROSS NRN FL AND IN THE LEE OF THE GREAT LAKES...PARTICULARLY INTO THE KEWEENAW PEN OF UPPER MI. HOWEVER...LIGHTNING POTENTIAL APPEARS QUITE LOW IN THESE AREAS. ..EVANS.. 12/02/2006  From swody1 at goshenarc.org Sat Dec 2 19:39:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 14:39:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021941 SWODY1 SPC AC 021939 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0139 PM CST SAT DEC 02 2006 VALID 022000Z - 031200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... CP AIR MASS COVERING MOST OF THE CONUS WILL PRECLUDE DEEP MOIST CONVECTION THROUGH TONIGHT. SHALLOW MOIST CONVECTION COULD OCCUR VCNTY A STALLED FRONT ACROSS NRN FL AND POSSIBLY IN THE LEE OF THE GRTLKS. LIGHTNING POTENTIAL...HOWEVER...WILL REMAIN QUITE LOW IN THESE AREAS /LESS THAN 10 PERCENT/. ..RACY/EVANS.. 12/02/2006  From swody1 at goshenarc.org Sun Dec 3 00:54:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Dec 2006 19:54:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030056 SWODY1 SPC AC 030054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0654 PM CST SAT DEC 02 2006 VALID 030100Z - 031200Z ...NO TSTM AREAS FORECAST... A BROAD CNTRL AND ERN U.S. UPPER-LEVEL TROUGH WILL REMAIN IN PLACE TONIGHT AS COLD SFC HIGH PRESSURE MOVES SWD INTO THE PLAINS STATES. THIS WILL REINFORCE NLY FLOW ACROSS THE CONUS WITH LOW-LEVEL MOISTURE MAINLY CONFINED TO THE FL PENINSULA. HOWEVER...LARGE-SCALE ASCENT SHOULD BE INSUFFICIENT ACROSS FL FOR THE DEVELOPMENT OF THUNDERSTORM ACTIVITY TONIGHT. ..BROYLES.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 05:22:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 00:22:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030524 SWODY1 SPC AC 030522 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 PM CST SAT DEC 02 2006 VALID 031200Z - 041200Z ...NO SVR TSTM AREAS FORECAST... A BROAD UPPER-LEVEL TROUGH OVER THE PLAINS STATES WILL DIG SEWD INTO THE MS VALLEY SUNDAY. AT THE SFC...A LOW AND WARM FRONT OFF THE COAST OF THE CAROLINAS WILL MOVE TOWARD THE COAST DURING THE DAY. THUNDERSTORM ACTIVITY ALONG THE WARM FRONT WILL BECOME INCREASINGLY LIKELY BY EVENING DUE TO STRENGTHENING LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY AND A DEVELOPING LOW-LEVEL JET. A FEW THUNDERSTORMS MAY AFFECT PAMLICO SOUND AND THE CAPE HATTERAS NATIONAL SEASHORE BY SUNDAY EVENING. HOWEVER...INSTABILITY IS FORECAST TO REMAIN WEAK AND NO SEVERE THREAT IS ANTICIPATED SUNDAY. ..BROYLES.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 12:51:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 07:51:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031252 SWODY1 SPC AC 031250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 AM CST SUN DEC 03 2006 VALID 031300Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD...POSITIVE TILT TROUGH WILL CONTINUE TO MOVE SLOWLY E ACROSS THE CNTRL AND ERN U.S. THIS PERIOD AS E PACIFIC RIDGE REACHES THE W CST/GRT BASIN. PHASING OF SHORTWAVE IMPULSES NOW OVER THE SRN RCKYS AND UPR MS VLY WILL RESULT IN FURTHER AMPLIFICATION OF TROUGH OVER THE SRN PLNS. THIS IN TURN WILL LEAD TO SFC DEVELOPMENT LATER TODAY/TONIGHT ALONG FRONT STALLED OFF THE SC/NC CST. THE WAVE SHOULD ACCELERATE ENE INTO THE ATLANTIC TO A POSITION WELL OFF THE MARYLAND CST BY 12Z MONDAY. STRENGTHENING 925-850 MB WARM ADVECTION N OF SFC FRONT MAY YIELD SUFFICIENT ELEVATED INSTABILITY TO ALLOW ASSOCIATED CONVECTION/ POSSIBLE THUNDER TO GRAZE THE OUTER BANKS REGION OF NC THIS EVENING/EARLY TONIGHT. FAST EWD MOTION OF SFC WAVE AND LIMITED DEGREE OF MOISTURE/BUOYANCY IN ELEVATED UNSTABLE LAYER SUGGEST THAT COVERAGE OVER LAND SHOULD REMAIN LIMITED. ELSEWHERE...DESTABILIZATION OF FAIRLY SHALLOW /BELOW 700 MB/ MIXED LAYER MAY SUPPORT DEEPENING OF CONVECTION OVER THE UPR GRT LKS LATER TODAY/TONIGHT. OVERALL COOLNESS OF SOUNDINGS AND LIMITED CONVECTIVE DEPTHS SUGGEST THAT ANY THUNDER WILL REMAIN ISOLATED. ..CORFIDI.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 16:23:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 11:23:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031625 SWODY1 SPC AC 031622 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1022 AM CST SUN DEC 03 2006 VALID 031630Z - 041200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD...POSITIVE TILT TROUGH WILL CONTINUE TO MOVE SLOWLY E ACROSS THE CNTRL AND ERN U.S. THIS PERIOD AS E PACIFIC RIDGE REACHES THE W CST/GRT BASIN. PHASING OF SHORTWAVE IMPULSES NOW OVER THE SRN RCKYS AND UPR MS VLY WILL RESULT IN FURTHER AMPLIFICATION OF TROUGH OVER THE SRN PLNS. THIS IN TURN WILL LEAD TO SFC DEVELOPMENT LATER TODAY/TONIGHT ALONG FRONT STALLED OFF THE SC/NC CST. THE WAVE SHOULD ACCELERATE ENE INTO THE ATLANTIC TO A POSITION WELL OFF THE MARYLAND CST BY 12Z MONDAY. STRENGTHENING 925-850 MB WARM ADVECTION N OF SFC FRONT MAY YIELD SUFFICIENT ELEVATED INSTABILITY TO ALLOW ASSOCIATED CONVECTION/POSSIBLE THUNDER TO DEVELOP JUST OFF THE NC COAST THIS EVENING/EARLY TONIGHT. FAST EWD MOTION OF SFC WAVE AND LIMITED DEGREE OF MOISTURE/BUOYANCY IN ELEVATED UNSTABLE LAYER SUGGEST THAT COVERAGE OVER LAND SHOULD REMAIN LIMITED. ..EVANS/CORFIDI.. 12/03/2006  From swody1 at goshenarc.org Sun Dec 3 19:25:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 14:25:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031927 SWODY1 SPC AC 031925 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0125 PM CST SUN DEC 03 2006 VALID 032000Z - 041200Z ...NO TSTM AREAS FORECAST... UPPER TROUGH WILL AMPLIFY TONIGHT AS IT MOVES ACROSS THE ERN STATES. WEAK CYCLOGENESIS WAS OCCURRING OFF THE CAROLINA COAST ALONG AN OLD FRONT. THIS LOW WILL TRACK OFF THE MID-ATLANTIC COAST LATER TONIGHT. MID-LEVEL FRONTOGENESIS WILL INCREASE WITHIN NWRN PARTS OF THE DEVELOPING CYCLONE ACROSS THE OUTER BANKS OF NC TONIGHT RESULTING IN AN INCREASE IN CONVECTION. ISOLD LIGHTNING WILL BE POSSIBLE AS WEAK ELEVATED UPRIGHT AND SLANTWISE CAPE DEVELOP COINCIDENT WITH THE DEFORMATION BAND. COVERAGE OVER LAND AREAS WILL LIKELY BE LESS THAN 10 PERCENT WITH HIGHER TSTM PROBABILITIES IN THE OFFSHORE WATERS. ..RACY.. 12/03/2006  From swody1 at goshenarc.org Mon Dec 4 00:45:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Dec 2006 19:45:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040047 SWODY1 SPC AC 040045 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 PM CST SUN DEC 03 2006 VALID 040100Z - 041200Z ...NO TSTM AREAS FORECAST... A LARGE MS VALLEY UPPER-LEVEL TROUGH WILL MOVE EWD REACHING THE APPALACHIAN MTNS LATE TONIGHT. AT THE SFC...COLD HIGH PRESSURE WILL SETTLE INTO THE SCNTRL UNITED STATES. THIS WILL RESULT IN NLY FLOW ACROSS MUCH OF THE SRN PLAINS AND SERN U.S. WHICH WILL LIMIT LOW-LEVEL MOISTURE EXCEPT ACROSS THE FL PENINSULA. A SFC LOW CURRENTLY EXISTS OFF THE COAST OF WILMINGTON NC AND THIS FEATURE WILL MOVE NWD TO NEAR CAPE HATTERAS TONIGHT. STRONG LOW-LEVEL CONVERGENCE NEAR THE SFC LOW MAY ALLOW THUNDERSTORMS TO INITIATE LATE THIS EVENING. HOWEVER...MOST OF THE LIGHTNING WITH THE CONVECTION SHOULD REMAIN OFFSHORE. ..BROYLES.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 05:16:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 00:16:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040517 SWODY1 SPC AC 040515 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 PM CST SUN DEC 03 2006 VALID 041200Z - 051200Z ...NO TSTM AREAS FORECAST... NORTHWEST FLOW WILL BE IN PLACE MONDAY ACROSS MOST OF THE CONUS AS AN UPPER-LEVEL TROUGH BROADENS AND MOVES ACROSS THE ERN SEABOARD. AT THE SFC...HIGH PRESSURE WILL DOMINATE ACROSS THE SRN U.S. AS ANOTHER COLD FRONT MOVES SWD ACROSS THE NCNTRL U.S. AS A RESULT...NLY FLOW WILL IMPEDE MOISTURE RETURN FROM THE GULF OF MEXICO AND THUNDERSTORMS ARE NOT EXPECTED ACROSS THE CONUS MONDAY OR MONDAY NIGHT. ..BROYLES.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 12:24:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 07:24:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041225 SWODY1 SPC AC 041222 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0622 AM CST MON DEC 04 2006 VALID 041300Z - 051200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD LONG WAVE TROUGH WILL PERSIST OVER THE ERN HALF OF NOAM THIS PERIOD AS LOW AMPLITUDE RIDGE CONTINUES ALONG THE CA CST. SFC WAVE NOW WELL OFF THE MD/DE CST SHOULD FURTHER DEEPEN AS IT CONTINUES RAPIDLY NEWD LATER TODAY AND TUESDAY. FARTHER W...NEXT SIGNIFICANT IMPULSE IN PERSISTENT WNWLY JET IS OVER MN/WI. THIS FEATURE SHOULD REACH PA/NY BY 12Z TUESDAY...WITH MINIMAL ADDITIONAL DEVELOPMENT. ISOLATED TSTMS LIKELY WILL PERSIST INVOF ACCELERATING SFC WAVE/COLD FRONT OVER THE N ATLANTIC CSTL WATERS FOR A FEW MORE HOURS THIS MORNING. LATER IN THE PERIOD...CONVECTION MAY DEEPEN AND YIELD A LIGHTNING STRIKE OR TWO OVER ERN LK HURON AS BOUNDARY LAYER DESTABILIZES IN WAKE OF PASSING UPR DISTURBANCE. ..CORFIDI.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 15:57:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 10:57:38 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041558 SWODY1 SPC AC 041556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0956 AM CST MON DEC 04 2006 VALID 041630Z - 051200Z ...NO TSTM AREAS FORECAST... ..EVANS.. 12/04/2006  From swody1 at goshenarc.org Mon Dec 4 20:00:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 15:00:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042001 SWODY1 SPC AC 041958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST MON DEC 04 2006 VALID 042000Z - 051200Z ...NO TSTM AREAS FORECAST... NO ORGANIZED AREAS OF THUNDERSTORM ACTIVITY ARE ANTICIPATED TODAY. ..HART.. 12/04/2006  From swody1 at goshenarc.org Tue Dec 5 00:39:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Dec 2006 19:39:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050041 SWODY1 SPC AC 050038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0638 PM CST MON DEC 04 2006 VALID 050100Z - 051200Z ...NO TSTM AREAS FORECAST... NORTHWEST FLOW WILL REMAIN IN PLACE ACROSS THE CONUS TONIGHT. AT THE SFC...HIGH PRESSURE WILL DOMINATE IN THE PLAINS AND SERN UNITED STATES KEEPING LOW-LEVEL MOISTURE AT BAY IN THE GULF OF MEXICO. FOR THIS REASON...THUNDERSTORM ACTIVITY IS NOT EXPECTED ACROSS THE CONUS TONIGHT. ..BROYLES.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 05:02:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 00:02:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050504 SWODY1 SPC AC 050502 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1102 PM CST MON DEC 04 2006 VALID 051200Z - 061200Z ...NO TSTM AREAS FORECAST... A BROAD UPPER-TROUGH WILL MOVE OFF THE ERN SEABOARD THIS MORNING AS ANOTHER SHORTWAVE TROUGH DIGS SEWD INTO THE NRN PLAINS TODAY. AT THE SFC...HIGH PRESSURE WILL DOMINATE THE ERN HALF OF THE NATION WITH ANOTHER COLD FRONT MOVING SWD INTO THE PLAINS STATES AND UPPER MIDWEST. ALTHOUGH SLY FLOW WILL RETURN TO THE SRN PLAINS AND MS VALLEY...SIGNIFICANT LOW-LEVEL MOISTURE RETURN WILL BE DELAYED. AS A RESULT...THUNDERSTORMS ARE NOT EXPECTED ACROSS THE CONUS TUESDAY AND TUESDAY NIGHT. ..BROYLES.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 12:21:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 07:21:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051223 SWODY1 SPC AC 051221 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0621 AM CST TUE DEC 05 2006 VALID 051300Z - 061200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... BROAD LONG WAVE TROUGH WILL PERSIST OVER THE ERN TWO THIRDS OF NOAM THIS PERIOD. ONE LOW AMPLITUDE SHORTWAVE DISTURBANCE NOW OVER THE UPR OH VLY WILL EXIT THE NERN STATES LATER TODAY AS UPSTREAM IMPULSE OVER SRN SASKATCHEWAN DROPS SE/ESE ACROSS THE UPR MS VLY/UPR GRT LKS. SFC RIDGING OVER THE GULF OF MEXICO AND DRY LOW LEVEL ENVIRONMENT WILL CONTINUE TO PROHIBIT DEEP CONVECTIVE DEVELOPMENT ACROSS THE NATION THIS PERIOD. MODERATE LAKE-ENHANCED CONVECTIVE BANDS/ CLUSTERS NOW PRESENT E OF LKS ERIE AND ONTARIO SHOULD DIMINISH LATER TODAY AS BOUNDARY LAYER BECOMES MORE SHALLOW IN WAKE OF PASSING UPR TROUGH. ..CORFIDI.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 16:10:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 11:10:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051611 SWODY1 SPC AC 051608 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1008 AM CST TUE DEC 05 2006 VALID 051630Z - 061200Z ...NO TSTM AREAS FORECAST... ..SYNOPSIS/FORECAST... BROAD LONG WAVE TROUGH WILL PERSIST OVER THE ERN TWO THIRDS OF NOAM THIS PERIOD. ONE LOW AMPLITUDE SHORTWAVE DISTURBANCE NOW OVER THE UPR OH VLY WILL EXIT THE NERN STATES LATER TODAY AS UPSTREAM IMPULSE OVER SRN SASKATCHEWAN DROPS SE/ESE ACROSS THE UPR MS VLY/UPR GRT LKS. SFC RIDGING OVER THE GULF OF MEXICO AND DRY LOW LEVEL ENVIRONMENT WILL CONTINUE TO PROHIBIT DEEP CONVECTIVE DEVELOPMENT ACROSS THE NATION THIS PERIOD. MODERATE LAKE-ENHANCED CONVECTIVE BANDS/CLUSTERS NOW PRESENT E OF LKS ERIE AND ONTARIO SHOULD DIMINISH LATER TODAY AS BOUNDARY LAYER BECOMES MORE SHALLOW IN WAKE OF PASSING UPR TROUGH. ..EVANS/CORFIDI.. 12/05/2006  From swody1 at goshenarc.org Tue Dec 5 19:23:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 14:23:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051924 SWODY1 SPC AC 051922 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0122 PM CST TUE DEC 05 2006 VALID 052000Z - 061200Z ...NO TSTM AREAS FORECAST... ..DARROW.. 12/05/2006  From swody1 at goshenarc.org Wed Dec 6 00:57:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Dec 2006 19:57:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060058 SWODY1 SPC AC 060056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST TUE DEC 05 2006 VALID 060100Z - 061200Z ...NO SVR TSTM AREAS FORECAST... A LARGE LOW-AMPLITUDE UPPER-LEVEL TROUGH WILL BE IN PLACE ACROSS THE CNTRL AND ERN U.S. TONIGHT. AT THE SFC...A TROUGH WILL MOVE SEWD ACROSS THE PLAINS STATES AS A SFC HIGH MOVES OFF THE ERN SEABOARD. LOW-LEVEL MOISTURE WILL REMAIN CONFINED TO THE SRN FL PENINSULA. HOWEVER...A LACK OF LARGE-SCALE ASCENT SHOULD KEEP ANY CONVECTION VERY ISOLATED. ELSEWHERE...THUNDERSTORM ACTIVITY IS NOT EXPECTED ACROSS THE CONUS. ..BROYLES.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 05:58:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 00:58:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060600 SWODY1 SPC AC 060557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST TUE DEC 05 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... A BROAD POSITIVELY TILTED UPPER-LEVEL TROUGH WILL AMPLIFY AS A DISTURBANCE MOVES QUICKLY SWD OUT OF CANADA TODAY AND TONIGHT. IN RESPONSE...A COLD FRONT WILL DIVE SWD ACROSS THE PLAINS AND UPPER MIDWEST. ISOLATED CONVECTION MAY DEVELOP THIS EVENING OVER LAKE SUPERIOR DUE TO WARM LAKE WATERS AND COLD AIR ALOFT WITH THE UPPER-TROUGH. IN ADDITION...THUNDERSTORMS WILL BE POSSIBLE OFF THE COAST OF THE ERN SEABOARD AS A SUBTLE LEAD SHORTWAVE TROUGH EJECTS OUT AHEAD OF THE LARGER GREAT LAKES TROUGH. NO THUNDERSTORM ACTIVITY IS EXPECTED TO REACH SEVERE LIMITS TODAY OR TONIGHT. ..BROYLES.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 12:57:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 07:57:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061258 SWODY1 SPC AC 061256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 AM CST WED DEC 06 2006 VALID 061300Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... THE LAST IN A SERIES OF SHORT WAVE DISTURBANCES REINFORCING LONG WAVE TROUGH OVER ERN NOAM WILL AMPLIFY AS IT DROPS SSE FROM SASKATCHEWAN/MANITOBA INTO WI/MI BY 12Z THURSDAY...WHILE PROGRESSIVE W CST RIDGE REACHES THE GRT BASIN/CANADIAN RCKYS. AT LOWER LEVELS...HIGH PRESSURE WILL EXPAND RAPIDLY SWD INTO THE N CNTRL STATES IN WAKE OF AMPLIFYING UPR TROUGH. AHEAD OF ASSOCIATED PRESSURE SURGE/COLD FRONT...A WEAKER COLD FRONT WILL SETTLE SE INTO E TX AND THE NWRN GULF...AND E/SE TOWARD THE ERN SEABOARD. DRY LOW LEVEL CONDITIONS AND SUBSIDENCE INVERSIONS WILL LIMIT DEPTH OF CONVECTIVE DEVELOPMENT OVER MOST OF THE LWR 48. SHOWERS AND POSSIBLE EMBEDDED TSTMS COULD...HOWEVER...DEVELOP LATE IN THE PERIOD JUST OFF THE MIDDLE TX GULF CST...WHERE UPLIFT ALONG WEAK FRONT MAY BE ENHANCED BY JET ENTRANCE REGION ASCENT ASSOCIATED WITH AMPLIFYING NRN STREAM IMPULSE. SCTD TSTMS MAY ALSO FORM LATE IN THE PERIOD OFF THE NC CST...WHERE LOW LEVEL CONVERGENCE/MOISTURE INFLOW WILL INCREASE AHEAD OF APPROACHING COLD FRONT. OVER THE GRT LKS...MID LEVEL COLD ADVECTION COUPLED WITH FAVORABLE OVER-LAKE FETCHES MAY RESULT IN CONVECTION SUFFICIENTLY DEEP/SUSTAINED TO YIELD A FEW LIGHTNING STRIKES DURING THE LAST HALF OF THE PERIOD OVER LKS SUPERIOR AND MICHIGAN. ..CORFIDI.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 15:51:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 10:51:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061552 SWODY1 SPC AC 061551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0951 AM CST WED DEC 06 2006 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... TESTING. THE 1630Z OUTLOOK WILL BE ISSUED SHORTLY. TESTING. ..AFWA.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 16:27:52 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 11:27:52 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061629 SWODY1 SPC AC 061627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST WED DEC 06 2006 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER GREAT LAKES... APPEARS MOST LIKELY AREA FOR CHARGE SEPARATION WITHIN MOIST CONVECTION WILL OCCUR OVER LAKE SUPERIOR AND POSSIBLY ERN LAKE MI LATER TONIGHT. VERY COLD UPPER LOW WILL SHIFT RAPIDLY SEWD ACROSS THE REGION THROUGH LATTER HALF OF THE PERIOD...WITH ACCOMPANYING -20C TO -24C H85 TEMPERATURES OVERSPREADING THE UPPER LAKES IN WAKE OF SURFACE COLD FRONT. GIVEN CURRENT LAKE SST AROUND 4C TO 7C... VERY STEEP LOW LEVEL LAPSE RATES WILL DEVELOP BENEATH INVERSION LAYER AROUND 750 MB. FORECAST SOUNDINGS SUPPORT SOME LIGHTNING POTENTIAL WITH STRENGTHENING LAKE EFFECT SNOW BANDS INTO UPPER MI LATER TODAY AND INTO PORTIONS OF WRN MI LATE TONIGHT. ...ELSEWHERE... MOIST CONVECTION WILL NOT LIKELY BECOME ROBUST ENOUGH FOR LIGHTNING ACTIVITY OVER SRN FL AND FAR ERN NC THIS PERIOD...AS MOST ACTIVITY REMAINS OFFSHORE. ..EVANS.. 12/06/2006  From swody1 at goshenarc.org Wed Dec 6 19:48:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 14:48:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061950 SWODY1 SPC AC 061948 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0148 PM CST WED DEC 06 2006 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER GREAT LAKES... STRONG COLD ADVECTION THROUGH THE LOWER TROPOSPHERE WILL STEEPEN LAPSE RATES SIGNIFICANTLY OVER LAKE SUPERIOR THIS AFTERNOON/EVENING...WITH STRONG COOLING EXPECTED LATER OVER THE REMAINDER OF LAKE MI. CONVECTION WILL GRADUALLY DEVELOP/EXPAND ACROSS LAKE SUPERIOR INTO THE EVENING HOURS AND ISOLATED LIGHTING MAY DEVELOP WITH HEAVIER SNOW BANDS...ESPECIALLY AFTER DARK. ..DARROW.. 12/06/2006  From swody1 at goshenarc.org Thu Dec 7 00:35:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 06 Dec 2006 19:35:30 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070036 SWODY1 SPC AC 070034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST WED DEC 06 2006 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WESTERN GREAT LAKES... ARCTIC COLD FRONT HAS MOVED THROUGH THE U.P AND WI AND WILL SWEEP SEWD ACROSS THE REMAINDER OF THE GREAT LAKES REGION OVERNIGHT. STRONG COLD ADVECTION THROUGHOUT THE LOWER TROPOSPHERE WAS STEEPENING LOW LEVEL LAPSE RATES OVER LAKE SUPERIOR...WITH THESE STEEPER LAPSE RATES EXPECTED TO EXPAND SEWD INTO THE WRN PORTIONS OF LOWER MI BETWEEN 06-12Z. THIS WILL RESULT IN LAKE EFFECT CONVECTION TO GRADUALLY DEEPEN WITH TIME AND INCREASE THE THREAT FOR LIGHTNING...ESPECIALLY AFTER 06Z. ..IMY.. 12/07/2006  From swody1 at goshenarc.org Thu Dec 7 19:26:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 14:26:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071927 SWODY1 SPC AC 071926 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0126 PM CST THU DEC 07 2006 VALID 072000Z - 081200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... MERIDIONAL PATTERN EXISTS ACROSS THE COUNTRY WITH A DEEP TROUGH IN THE EASTERN CONUS AND A RIDGE IN THE WEST. THE EASTERN TROUGH IS FORCING A STRONG SURFACE COLD FRONT THROUGH MOST OF THE COUNTRY EAST OF THE ROCKIES...LEADING TO A COLD AND STABLE BOUNDARY LAYER IN MOST AREAS. ADDITIONALLY...SHORTWAVE ENERGY IS UNDERCUTTING THE RIDGE IN NORTHERN MEXICO WHERE A CLOSED UPPER LOW IS EXPECTED TO FORM LATER TODAY. ...GREAT LAKES... VERY COLD AIR AT ALL LEVELS IS OVERSPREADING THE GREAT LAKES WHERE WATER TEMPERATURES ARE GENERALLY FROM 2 TO 8 DEGREES C...LEADING TO INSTABILITY AND CONVECTIVE SNOW BANDS IN LOCATIONS WHERE THE SURFACE FETCH IS DOWNSTREAM FROM THE LAKE. THE CORE OF THE COLDEST AIR IS ADVECTING OVER TOP LAKE ERIE...AND SOME ISOLATED LIGHTNING IS POSSIBLE OVER THE LAKE AND ON THE SOUTHERN SHORES GIVEN EXPECTED MIXED PHASE CLOUD CONTENT AND CAPES AROUND 250 J/KG. HOWEVER...WITH NORTHWESTERLY SURFACE FLOW THE FETCHES WILL BE LIMITED AND GIVEN THAT NO LIGHTNING HAS BEEN OBSERVED THUS FAR...COVERAGE IS EXPECTED TO BE LESS THAN 10 PERCENT. ...FLORIDA... THE COLD FRONT IS PUSHING SLOWLY SOUTHWARD THROUGH FLORIDA GENERATING SOME SHOWER ACTIVITY. INSTABILITY IS LACKING EXCEPT IN EXTREME SOUTHERN FLORIDA...WHERE FORCING AND MID LEVEL LAPSE RATES ARE WEAK DESPITE AMPLE LOW LEVEL MOISTURE...AND EVEN THAT IS SLOWLY DECREASING AS DRIER AIR FILTERS IN FROM THE NORTH. ISOLATED LIGHTNING IS POSSIBLE IF LOCAL BOUNDARY INTERACTIONS CAN GENERATE ENOUGH FORCING FOR DEEP CONVECTION...BUT WIDESPREAD COVERAGE IS NOT EXPECTED. ...SOUTHERN TEXAS... SHOWER ACTIVITY IS ONGOING ALONG THE FRONT ENHANCED BY THE RIGHT REAR QUADRANT OF A JET STREAK AT THE BASE OF THE TROUGH. SOUNDINGS INDICATE A MOIST ADIABATIC ATMOSPHERE AND LIMITED INSTABILITY...PRECLUDING LIGHTNING. A SHORTWAVE IN THE SUBTROPICAL JET STREAM WILL BEGIN TO IMPACT THE REGION BUT NOT BEFORE THE COLD FRONT HAS CLEARED THE AREA...LEADING TO STABLE CONDITIONS. ..AFWA.. 12/07/2006  From swody1 at goshenarc.org Thu Dec 7 19:46:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 14:46:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071947 SWODY1 SPC AC 071926 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0126 PM CST THU DEC 07 2006 VALID 072000Z - 081200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... MERIDIONAL PATTERN EXISTS ACROSS THE COUNTRY WITH A DEEP TROUGH IN THE EASTERN CONUS AND A RIDGE IN THE WEST. THE EASTERN TROUGH IS FORCING A STRONG SURFACE COLD FRONT THROUGH MOST OF THE COUNTRY EAST OF THE ROCKIES...LEADING TO A COLD AND STABLE BOUNDARY LAYER IN MOST AREAS. ADDITIONALLY...SHORTWAVE ENERGY IS UNDERCUTTING THE RIDGE IN NORTHERN MEXICO WHERE A CLOSED UPPER LOW IS EXPECTED TO FORM LATER TODAY. ...GREAT LAKES... VERY COLD AIR AT ALL LEVELS IS OVERSPREADING THE GREAT LAKES WHERE WATER TEMPERATURES ARE GENERALLY FROM 2 TO 8 DEGREES C...LEADING TO INSTABILITY AND CONVECTIVE SNOW BANDS IN LOCATIONS WHERE THE SURFACE FETCH IS DOWNSTREAM FROM THE LAKE. THE CORE OF THE COLDEST AIR IS ADVECTING OVER TOP LAKE ERIE...AND SOME ISOLATED LIGHTNING IS POSSIBLE OVER THE LAKE AND ON THE SOUTHERN SHORES GIVEN EXPECTED MIXED PHASE CLOUD CONTENT AND CAPES AROUND 250 J/KG. HOWEVER...WITH NORTHWESTERLY SURFACE FLOW THE FETCHES WILL BE LIMITED AND GIVEN THAT NO LIGHTNING HAS BEEN OBSERVED THUS FAR...COVERAGE IS EXPECTED TO BE LESS THAN 10 PERCENT. ...FLORIDA... THE COLD FRONT IS PUSHING SLOWLY SOUTHWARD THROUGH FLORIDA GENERATING SOME SHOWER ACTIVITY. INSTABILITY IS LACKING EXCEPT IN EXTREME SOUTHERN FLORIDA...WHERE FORCING AND MID LEVEL LAPSE RATES ARE WEAK DESPITE AMPLE LOW LEVEL MOISTURE...AND EVEN THAT IS SLOWLY DECREASING AS DRIER AIR FILTERS IN FROM THE NORTH. ISOLATED LIGHTNING IS POSSIBLE IF LOCAL BOUNDARY INTERACTIONS CAN GENERATE ENOUGH FORCING FOR DEEP CONVECTION...BUT WIDESPREAD COVERAGE IS NOT EXPECTED. ...SOUTHERN TEXAS... SHOWER ACTIVITY IS ONGOING ALONG THE FRONT ENHANCED BY THE RIGHT REAR QUADRANT OF A JET STREAK AT THE BASE OF THE TROUGH. SOUNDINGS INDICATE A MOIST ADIABATIC ATMOSPHERE AND LIMITED INSTABILITY...PRECLUDING LIGHTNING. A SHORTWAVE IN THE SUBTROPICAL JET STREAM WILL BEGIN TO IMPACT THE REGION BUT NOT BEFORE THE COLD FRONT HAS CLEARED THE AREA...LEADING TO STABLE CONDITIONS. ..AFWA.. 12/07/2006  From swody1 at goshenarc.org Fri Dec 8 00:38:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 19:38:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080039 SWODY1 SPC AC 080036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0636 PM CST THU DEC 07 2006 VALID 080100Z - 081200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SURFACE HIGH PRESSURE...COVERING MOST THE NATION...IS RESULTING IN AN ENVIRONMENT GENERALLY TOO STABLE FOR THUNDERSTORMS. THOUGH WEAK CONVECTION WAS NOTED WITHIN LAKE EFFECT SNOWBANDS... THIS VERY LOW TOPPED CONVECTION SHOULD GRADUALLY DIMINISH AS COLD UPPER TROUGH SHIFTS EAST OF THE REGION. ELEVATED WEAK CONVECTION WAS ALSO LOCATED ACROSS THE NRN FL PENINSULA..BEHIND SURFACE FRONT. WIDESPREAD PRECIPITATION WAS LOCATED ACROSS SRN TX...AHEAD OF A SHORTWAVE TROUGH IN MEXICO. LIMITED INSTABILITY SHOULD LIMIT VERTICAL CLOUD DEPTH AND LIGHTNING ACROSS BOTH OF THESE AREAS. ..IMY.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 04:47:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 07 Dec 2006 23:47:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080448 SWODY1 SPC AC 080446 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1046 PM CST THU DEC 07 2006 VALID 081200Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... DEEP AND COLD UPPER TROUGH IN THE NORTHEAST WILL MOVE OFFSHORE FRIDAY AFTERNOON...AS A WEAKER TROUGH MOVES ONSHORE ALONG THE PACIFIC COAST. BETWEEN THESE TWO SYSTEMS...A RIDGE ALOFT SHOULD RESULT IN THE COUNTRY TO BE THUNDER FREE. THE ONLY EXCEPTION MIGHT BE NEAR THE CA COAST...AS COLD AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH...SPREADS INLAND. HOWEVER...THE LACK OF INSTABILITY AND MOIST ADIABATIC PROFILES SUGGEST THE THREAT FOR MORE THAN A LIGHTNING STRIKE OR TWO IS TOO LOW TO WARRANT A THUNDER OUTLOOK. ..IMY.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 12:49:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 07:49:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081250 SWODY1 SPC AC 081248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0648 AM CST FRI DEC 08 2006 VALID 081300Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... SOME EWD PROGRESSION OF THE DEEP ERN STATES MID LEVEL TROUGH AND THE RIDGE OVER THE ROCKIES IS EXPECTED THROUGH TOMORROW AS THE FIRST IN A SERIES OF SHORTWAVE TROUGHS APPROACHES THE CA COAST. THUNDERSTORMS ARE NOT EXPECTED ACROSS THE MAJORITY OF THE CONUS AS A RESULT OF STRONG SURFACE RIDGING AND OFFSHORE FLOW ACROSS THE GULF AND ATLANTIC COASTS. THE TROUGH NEAR 130 W WILL REACH CA THIS EVENING...THOUGH THE WAVE SHOULD LOSE SOME AMPLITUDE IS IT ENCROACHES ON THE BROAD RIDGE OVER THE INTERMOUNTAIN WEST. A COUPLE OF LIGHTNING STRIKES HAVE BEEN NOTED IN OCEANIC LIGHTNING DATA...BUT WEAKENING OF THIS SYSTEM WITH TIME SUGGESTS THAT ANY THUNDERSTORM THREAT SHOULD DIMINISH BEFORE REACHING THE CA COAST. OTHERWISE...ANY WEAK MID LEVEL INSTABILITY ASSOCIATED WITH THE LOW OVER NW MEXICO SHOULD REMAIN S OF THE RIO GRANDE. ..THOMPSON.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 16:03:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 11:03:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081602 SWODY1 SPC AC 081559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0959 AM CST FRI DEC 08 2006 VALID 081630Z - 091200Z ...NO TSTM AREAS FORECAST... UPPER RIDGE CURRENTLY OVER THE WESTERN UNITED STATES IS EXPECTED TO MOVE EASTWARD TODAY...ALLOWING HIGH-AMPLITUDE TROUGH OFF THE PACIFIC COAST TO MOVE INLAND. COLD TEMPERATURES ALOFT MAY RESULT IN ISOLATED LIGHTNING STRIKES OFF THE CA COAST TODAY. HOWEVER...THREAT FOR THUNDERSTORMS OVER THE MAINLAND APPEARS LOW. ELSEWHERE...NO ORGANIZED THUNDERSTORM ACTIVITY IS FORECAST TODAY. ..HART.. 12/08/2006  From swody1 at goshenarc.org Fri Dec 8 19:15:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 14:15:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081916 SWODY1 SPC AC 081913 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0113 PM CST FRI DEC 08 2006 VALID 082000Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... AN UPPER RIDGE WILL CONTINUE TO SHIFT SLOWLY EWD ACROSS THE CENTRAL CONUS THROUGH THE REMAINDER OF THIS PERIOD...WHILE ONE SHORT-WAVE TROUGH MOVES ONSHORE ACROSS THE WEST AND A SECOND CONTINUES TO DEPART THE EAST. WITH ANY APPRECIABLE LIGHTNING ACTIVITY THIS PERIOD FORECAST TO REMAIN OFFSHORE AS STABLE AIRMASS PREVAILS ACROSS THE CONUS...WILL MAINTAIN FORECAST FOR LESS THAN 10% THUNDERSTORM COVERAGE. ..GOSS.. 12/08/2006  From swody1 at goshenarc.org Sat Dec 9 00:44:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 19:44:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090045 SWODY1 SPC AC 090043 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0643 PM CST FRI DEC 08 2006 VALID 090100Z - 091200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... SURFACE RIDGE AT THE SURFACE AND ALOFT COVERS A MAJORITY OF THE NATION...RESULTING IN GENERALLY STABLE AND DRY CONDITIONS. THE EXCEPTION INCLUDED PRECIPITATION IN SRN TX AND THE PACIFIC COAST AS SHORTWAVE TROUGHS APPROACHED BOTH REGIONS. HOWEVER...LIMITED INSTABILITY SHOULD PRECLUDE A LIGHTNING THREAT ACROSS BOTH AREAS. ..IMY.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 04:44:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Dec 2006 23:44:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090445 SWODY1 SPC AC 090441 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1041 PM CST FRI DEC 08 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ..SYNOPSIS... SHORTWAVE TROUGH...CURRENTLY LOCATED ABOUT 800 MILES WEST OF SFO...IS MOVING EWD AT 35 KT AND THIS MOTION WOULD BRING THE SYSTEM INTO CA SATURDAY NIGHT. THOUGH INSTABILITY IS FORECAST TO REMAIN MARGINAL...MUCAPES AOB 350 J/KG...STRONG FORCING AND MID LEVEL LAPSE RATES NEAR 7C/KM SHOULD SUPPORT CONVECTION WITH SOME LIGHTNING BETWEEN 21-06Z. THUNDERSTORMS ARE EXPECTED BE MOST NUMEROUS OFFSHORE AND ALONG THE COAST...WHERE THE INSTABILITY WILL BE THE GREATEST. ELSEWHERE...LARGE SURFACE HIGH PRESSURE AND ASSOCIATED STABLE AIRMASS WILL INHIBIT CONVECTION ACROSS THE REMAINDER OF THE CONUS. ..IMY.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 13:00:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 08:00:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091301 SWODY1 SPC AC 091259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST SAT DEC 09 2006 VALID 091300Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE LARGE SCALE PATTERN IS BECOMING MORE ZONAL/PROGRESSIVE WITH TIME...THOUGH A RELATIVELY COLD/DRY CONTINENTAL AIR MASS IN THE LOW LEVELS WILL INHIBIT DEEP CONVECTION OVER THE MAJORITY OF THE CONUS. A WEAKENING SRN STREAM WAVE OVER NE MEXICO WILL MOVE OVER S TX...BUT THUNDERSTORMS ARE NOT EXPECTED GIVEN ONLY MINIMAL MID LEVEL INSTABILITY IN ASSOCIATION WITH THIS WAVE. A MORE SUBSTANTIAL THREAT FOR AT LEAST ISOLATED THUNDERSTORMS IS EXPECTED ACROSS THE NRN/CENTRAL CA COAST AND CENTRAL VALLEYS AS A SHORTWAVE TROUGH CURRENTLY LOCATED NEAR 35 N AND 130 W MOVES EWD TO THE CA COAST BY 00Z. SATELLITE IMAGERY AND OCEANIC LIGHTNING DATA SHOW EMBEDDED CONVECTION AND ISOLATED THUNDERSTORMS WITHIN THE INITIAL BAROCLINIC BAND AND NEAR THE COLD CORE. THESE AREAS OF CONVECTION WILL LIKELY PERSIST AND SPREAD INLAND THIS EVENING INTO TONIGHT ..THOMPSON.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 16:19:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 11:19:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091620 SWODY1 SPC AC 091618 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1018 AM CST SAT DEC 09 2006 VALID 091630Z - 101200Z ...NO SVR TSTM AREAS FORECAST... SATELLITE IMAGERY AND MODEL GUIDANCE SHOW NEXT IN A SERIES OF STRONG SHORTWAVE TROUGHS APPROACHING THE PACIFIC COAST. THIS FEATURE IS FORECAST TO MOVE ASHORE TONIGHT...PROVIDING STRONG ASCENT AND WIDESPREAD PRECIPITATION TO NORTHERN/CENTRAL CA AND PARTS OF SOUTHERN ORE. COLD TEMPERATURES ALOFT AND RELATIVELY STEEP MID LEVEL LAPSE RATES ARE EXPECTED TO RESULT IN POCKETS OF MARGINAL INSTABILITY OVERNIGHT. COMBINATION OF LARGE SCALE FORCING FOR ASCENT AND OROGRAPHIC FORCING WILL AID IN THE THREAT OF ISOLATED THUNDERSTORMS ACROSS THE REGION. NO SEVERE THUNDERSTORMS ARE ANTICIPATED. ELSEWHERE ACROSS THE NATION...RELATIVELY DRY/STABLE CONDITIONS ARE EXPECTED TO PRECLUDE THUNDERSTORM ACTIVITY. ..HART.. 12/09/2006  From swody1 at goshenarc.org Sat Dec 9 19:47:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 14:47:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091948 SWODY1 SPC AC 091946 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0146 PM CST SAT DEC 09 2006 VALID 092000Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AS AN UPPER SHORT-WAVE TROUGH MOVES EWD ACROSS THE ROCKIES AND EVENTUALLY INTO THE PLAINS WITHIN LARGER-SCALE UPPER RIDGE...A SECOND/STRONGER TROUGH WILL MOVE ONSHORE OVER THE WRN CONUS THROUGH THE SECOND HALF OF THE PERIOD. THE AIRMASS OVER THE CONUS FROM THE ROCKIES EWD SHOULD REMAIN UNSUPPORTIVE OF DEEP MOIST CONVECTION. HOWEVER...A FEW ONSHORE LIGHTNING STRIKES MAY OCCUR OVER PARTS OF NRN AND CENTRAL CA DURING THE SECOND HALF OF THE PERIOD...AS POSSIBLE AREAS OF MINIMAL INSTABILITY DEVELOP -- PARTICULARLY ALONG THE CA COAST. ..GOSS.. 12/09/2006  From swody1 at goshenarc.org Sun Dec 10 00:54:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Dec 2006 19:54:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100054 SWODY1 SPC AC 100052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 PM CST SAT DEC 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/NRN CA... FRONTAL BAND CONTINUES TO SPREAD ONSHORE NRN/CNTRL CA THIS EVE WITH EMBEDDED TSTMS. 00Z OAK SOUNDING STILL INDICATES A WARM LAYER JUST ABOVE 660 MB. THIS SUGGESTS THAT PRIMARY TSTM PROBABILITIES WITH THE FRONTAL BAND WILL MAINLY BE NORTH OF THE BAY AREA/CNTRL CA THIS EVE. BUT...AS PRIMARY COLD CORE ASSOCD WITH THE UPPER WAVE MOVES INLAND...POTENTIAL INSTABILITY/TSTM PROBABILITIES WILL SPREAD INLAND AND SWD WITH TIME PER LATEST RUC/NAM CROSS-SECTIONS. ..RACY.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 05:21:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 00:21:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100522 SWODY1 SPC AC 100519 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 PM CST SAT DEC 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL CA... THE MID-LEVEL SHORTWAVE TROUGH MOVING ASHORE CNTRL/NRN CA EARLY SUNDAY MORNING WILL QUICKLY TRANSLATE EWD INTO THE INTERMOUNTAIN WEST BY MID-DAY. H5 TEMPERATURES IN THE MID-MINUS 20S ATOP A PLUME OF MODEST PRECIPITABLE WATER VALUES MAY BE SUFFICIENT FOR EARLY DAY TSTMS IN THE BAY AREA AND PARTS OF THE CNTRL VLY. THE TSTM PROBABILITY WILL DECREASE DURING THE AFTN AS WARMING ALOFT/REBOUNDING HEIGHTS OCCUR IN WAKE OF THE WAVE. ...GREAT BASIN/FOUR CORNERS REGION... THE MID-LEVEL WAVE MOVING INTO CNTRL/NRN CA WILL ARRIVE ACROSS THE GREAT BASIN AND FOUR-CORNERS REGION BY SUNDAY AFTN. STEEPENING MID-TROPOSPHERIC LAPSE RATES AND MODEST LARGE SCALE ASCENT MAY BE SUFFICIENT FOR ISOLD LIGHTNING STRIKES FROM CNTRL/SRN UT AND NRN AZ EWD INTO SWRN CO...PRIMARILY BETWEEN 15-03Z. ..RACY.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 12:54:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 07:54:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101254 SWODY1 SPC AC 101252 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 AM CST SUN DEC 10 2006 VALID 101300Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE MID LEVEL SHORTWAVE TROUGH NOW MOVING FROM CENTRAL CA INTO NV WILL CONTINUE EWD OVER THE FOUR CORNERS BY THIS EVENING...REACHING THE HIGH PLAINS EARLY MONDAY. THE APPROACHING WAVE WILL INDUCE LEE CYCLOGENESIS ACROSS ERN CO AND SLY LOW-LEVEL FLOW ACROSS THE SRN PLAINS. A FEW SHALLOW CONVECTIVE SHOWERS ARE EXPECTED ACROSS SE TX WITHIN A MOISTENING WAA REGIME. HOWEVER...LOW-LEVEL TRAJECTORIES AND MID LEVEL LAPSE RATES DO NOT SUPPORT SUFFICIENT DESTABILIZATION FOR THUNDERSTORMS THIS PERIOD. ...CENTRAL CA TODAY AND THE FOUR CORNERS THIS AFTERNOON... ISOLATED LIGHTNING STRIKES HAVE BEEN NOTED IN NLDN DATA ACROSS CENTRAL CA WITH THE INITIAL SHORTWAVE TROUGH. THIS THREAT SHOULD DIMINISH THIS MORNING AS THE WAVE MOVES E OF THE SIERRA NEVADA...THOUGH ADDITIONAL LOW-TOPPED CONVECTION MAY OCCUR THE FIRST HALF OF THE DAY AS A SECOND SHORTWAVE TROUGH MOVES INLAND. THERE WILL ALSO BE SOME THREAT FOR ISOLATED THUNDERSTORMS THIS AFTERNOON INVOF THE FOUR CORNERS WHERE DAYTIME HEATING...ASCENT/COOLING MID LEVEL TEMPERATURES...AND GRADUAL MOISTENING IN ADVANCE OF THE MID LEVEL WAVE SHOULD RESULT IN THE DEVELOPMENT OF WEAK INSTABILITY. ..THOMPSON.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 15:52:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 10:52:54 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101553 SWODY1 SPC AC 101551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0951 AM CST SUN DEC 10 2006 VALID 101630Z - 111200Z ...NO SVR TSTM AREAS FORECAST... STRONG...FAST MOVING UPPER TROUGH CONTINUES TO TRACK EASTWARD ACROSS THE WESTERN STATES THIS MORNING. THE INITIAL VORT LOBE HAS PASSED OVER THE SIERRAS...WITH LARGE SCALE FORCING FOR ASCENT NOW SPREADING EASTWARD ACROSS THE GREAT BASIN. STEEP LAPSE RATES...SUSTAINED LIFT...AND STRONG DAYTIME HEATING ARE EXPECTED TO RESULT IN A MARGINALLY UNSTABLE AIR MASS THIS AFTERNOON AND EVENING FROM SOUTHERN UT/NORTHERN AZ INTO WESTERN CO. ISOLATED LIGHTNING STRIKES MAY OCCUR ACROSS THIS AREA. ELSEWHERE...A GENERALLY DRY AND STABLE AIRMASS IS EXPECTED TO PRECLUDE THUNDERSTORM ACTIVITY. ..HART.. 12/10/2006  From swody1 at goshenarc.org Sun Dec 10 19:16:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 14:16:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101917 SWODY1 SPC AC 101914 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0114 PM CST SUN DEC 10 2006 VALID 102000Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHOWERS AND ISOLATED THUNDERSTORMS NOW OVER SRN UT/NRN AZ ARE FORECAST TO CONTINUE/SPREAD EWD ACROSS THE FOUR CORNERS REGION THROUGH THE END OF THE PERIOD...AS COLD AIR ALOFT ASSOCIATED WITH UPPER TROUGH TRAVERSING THE AREA IS YIELDING SUFFICIENT INSTABILITY FOR DEEP MOIST CONVECTION. ELSEWHERE...LACK OF CAPE SHOULD PRECLUDE THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD. ..GOSS.. 12/10/2006  From swody1 at goshenarc.org Mon Dec 11 00:44:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Dec 2006 19:44:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110045 SWODY1 SPC AC 110042 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 PM CST SUN DEC 10 2006 VALID 110100Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...FOUR CORNERS REGION... WATER VAPOR IMAGERY CLEARLY SHOWS THE MID-LEVEL SHORTWAVE TROUGH MIGRATING ACROSS THE SWRN DESERTS THIS EVENING. STRONGEST H5-H3 Q-VECTOR CONVERGENCE IS EXPECTED TO MOVE ACROSS THE SRN ROCKIES AND ONTO THE SRN PLAINS LATER TONIGHT. 00Z FGZ/ABQ/GJT OBSERVED AND RUC FORECAST SOUNDINGS SUGGEST THAT THE THERMODYNAMIC ENVIRONMENT WILL BE MARGINALLY SUPPORTIVE FOR ISOLD TSTMS WEST OF THE DIVIDE ACROSS THE FOUR CORNERS REGION THROUGH ABOUT 06Z. FARTHER E...A DRIER AIR MASS WILL LIMIT THE TSTM THREAT DESPITE THE INCREASE IN LARGE SCALE ASCENT. ..RACY.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 05:39:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 00:39:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110540 SWODY1 SPC AC 110537 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 PM CST SUN DEC 10 2006 VALID 111200Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID-MO/MS VLY/MIDWEST SWD TO THE WRN GULF COAST REGION... UPPER TROUGH OVER THE FOUR CORNERS REGION EARLY ON MONDAY WILL AMPLIFY THROUGH THE DAY WITH 120 METER HEIGHT FALLS SPREADING ACROSS THE SRN PLAINS TO THE UPPER MS VLY BY EARLY TUE. AT THE SFC...PRIMARY SFC LOW WILL EVOLVE AND MOVE ENEWD THROUGH KS TO IA BY LATE MON NIGHT. TRAILING THE LOW...A COLD FRONT/DRY LINE WILL MIGRATE EWD THROUGH THE CNTRL/SRN PLAINS. MODEST RETURN FLOW WILL CONTINUE ACROSS THE CNTRL/SRN PLAINS AND MS VLY MON/MON NIGHT IN ADVANCE OF THE UPPER SYSTEM. 00Z MON RAOBS...HOWEVER...SUGGEST THAT LAPSE RATES WILL REMAIN RATHER POOR UNTIL THE UPPER SYSTEM BEGINS TO TRANSLATE EWD. AS A RESULT...DEVELOPING WARM CONVEYOR/SHOWERS FROM ERN TX NWD INTO THE MIDWEST WILL LIKELY BE UNDERPRODUCTIVE WITH RESPECT TO LIGHTNING THROUGH THE DAYLIGHT HOURS. HIGHER TSTM PROBABILITIES WILL DEVELOP DURING THE NIGHT AS STEEPER MID-LEVEL LAPSE RATES ASSOCD WITH THE APPROACHING SYSTEM SPREAD ENEWD. SPORADIC LIGHTNING MAY OCCUR WITH EVOLVING CONVECTIVE BANDS DEVELOPING N-W OF THE PRIMARY SFC LOW BETWEEN 00-03Z ACROSS THE MID-MO VLY. THIS ACTIVITY WILL EVENTUALLY SPREAD NEWD TOWARD PARTS OF IA AND NRN IL OVERNIGHT. A SEPARATE REGION OF HIGHER TSTM PROBABILITIES WILL EXIST GENERALLY AFT 03-06Z FROM ERN TX NEWD INTO THE MIDWEST ALONG THE ADVANCING COLD FRONT. STRONGER STORMS ARE EXPECTED ACROSS THE LWR MS VLY AS ENHANCED ASCENT ASSOCD WITH A SECONDARY JET STREAK ARRIVES OVERNIGHT COINCIDENT WITH IMPROVING LAPSE RATES. ORGANIZED SEVERE TSTMS ARE NOT ANTICIPATED...HOWEVER. ..RACY.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 13:00:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 08:00:07 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111300 SWODY1 SPC AC 111258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 AM CST MON DEC 11 2006 VALID 111300Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...IA SWD TO LA THIS EVENING AND OVERNIGHT... A MID LEVEL SHORTWAVE TROUGH OVER THE CENTRAL/SRN HIGH PLAINS THIS MORNING WILL MOVE EWD OVER NE/KS/OK/N TX TODAY AND REACH IA/MO/AR/NW LA LATE IN THE PERIOD. AT THE SURFACE...AN ASSOCIATED LEE CYCLONE IN WRN KS WILL DEVELOP EWD ACROSS KS DURING THE DAY...AND THEN NEWD ACROSS NW MO INTO CENTRAL IA EARLY TUESDAY. LOW-LEVEL SLY FLOW IN ADVANCE OF THIS SYSTEM IS DRAWING A MODIFYING GULF AIR MASS NWD...WITH BOUNDARY LAYER DEWPOINTS IN THE LOWER 50S INTO ERN OK AND LOWER 60S ALONG THE UPPER TX COAST. THIS PLUME OF MOISTURE WILL SPREAD NEWD ACROSS LA/AR/MO LATER TODAY INTO TONIGHT. REGIONAL SOUNDINGS...HOWEVER...SUGGEST THAT THE STEEPER L0W-MID LEVEL LAPSE RATES ARE CONFINED TO THE MID LEVEL THERMAL TROUGH OVER THE HIGH PLAINS...AND THE GREATER POTENTIAL FOR DESTABILIZATION WILL BE DELAYED UNTIL THIS EVENING WHEN THESE LAPSE RATES OVERSPREAD THE NW PORTION OF THE LOW-LEVEL MOISTURE PLUME FROM NE KS INTO MO/IA. FARTHER S IN THE WARM SECTOR...GREATER BOUNDARY LAYER MOISTURE/VERTICAL SHEAR WILL BE COUNTERED BY POOR MID LEVEL LAPSE RATES. DESTABILIZATION SHOULD BE SUFFICIENT FOR DEEP CONVECTION BY THIS EVENING AND CONTINUING INTO THE OVERNIGHT HOURS. THE THREAT FOR LIGHTNING WILL GRADUALLY INCREASE BY EARLY TONIGHT WITHIN THE BAND OF SHOWERS FROM SE TX INTO AR AS THE MID LEVELS COOL AND CONVECTIVE CLOUD DEPTH DEEPENS. FARTHER N/NW...SOME SMALL HAIL MAY OCCUR IN CONJUNCTION WITH THE COLDEST MID LEVEL TEMPERATURES AND STEEPEST LAPSE RATES OVER NE KS/NRN MO/SRN IA. HOWEVER...THE THREAT FOR SEVERE STORMS WILL BE MINIMAL GIVEN THE VERY MARGINAL INSTABILITY. ..THOMPSON.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 16:21:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 11:21:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111622 SWODY1 SPC AC 111619 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1019 AM CST MON DEC 11 2006 VALID 111630Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MISSISSIPPI VALLEY... MORNING WATER VAPOR LOOPS SHOW THAT DEEP UPPER TROUGH HAS BECOME ESTABLISHED OVER THE SOUTH-CENTRAL UNITED STATES...WITH SERIES OF TRAILING SHORTWAVE TROUGHS MOVING ONTO THE PACIFIC COAST. RATHER STRONG SOUTH-SOUTHWESTERLY LOW LEVEL WINDS EXTEND FROM TX/LA INTO THE MIDWEST. THIS IS PROVIDING RATHER STRONG LOW LEVEL THERMAL/ MOISTURE ADVECTION AND SCATTERED PRECIPITATION. SHOWER ACTIVITY IS EXPECTED TO PERSIST AND SPREAD EASTWARD THROUGH THE DAY. HOWEVER... GENERAL LACK OF SUFFICIENT INSTABILITY WILL LIKELY PRECLUDE MORE THAN ISOLATED LIGHTNING STRIKES WITHIN CONVECTIVE ACTIVITY. GREATER THREAT OF THUNDERSTORMS MAY DEVELOP LATER TONIGHT ACROSS PARTS OF MO/IL/IA AND POSSIBLY NORTHERN AR AS PLUME OF STEEPER MID LEVEL LAPSE RATES OVERSPREADS REGION. CAPE VALUES WILL REMAIN QUITE LOW. HOWEVER...LARGE SCALE ASCENT AND CONTINUED INFLUX OF LOW LEVEL MOISTURE MAY PROVE SUFFICIENT FOR SCATTERED THUNDERSTORMS CAPABLE OF SMALL HAIL. NO ORGANIZED SEVERE STORMS ARE EXPECTED. ...WA/ORE... SHORTWAVE TROUGH JUST OFF THE WA/ORE/CA COAST WILL MOVE INLAND TODAY. STRONG ONSHORE FLOW AND COLD TEMPERATURES ALOFT WILL POSE A RISK OF ISOLATED THUNDERSTORMS ALONG THE COASTAL RANGES FROM WESTERN WA INTO ORE. ..HART.. 12/11/2006  From swody1 at goshenarc.org Mon Dec 11 19:35:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 14:35:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111936 SWODY1 SPC AC 111934 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0134 PM CST MON DEC 11 2006 VALID 112000Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...CENTRAL STATES... AMPLIFIED MID/UPPER TROUGH CONTINUES TO PROGRESS EAST OF THE ROCKIES INTO THE PLAINS...WITH A 70+ KT SOUTHWESTERLY 500 MB JET STREAK NOSING ACROSS THE SOUTH CENTRAL PLAINS INTO THE MID/LOWER MISSOURI VALLEY REGION. HOWEVER...LEE SURFACE LOW DEVELOPMENT OVER KANSAS REMAINS WEAK...AND LOW-LEVEL MOISTURE RETURN FROM THE GULF OF MEXICO...STILL MODIFYING IN THE WAKE OF SERIES OF SIGNIFICANT COLD INTRUSIONS...IS JUST UNDERWAY. MID/UPPER 50S SURFACE DEW POINTS HAVE REACHED THE ARKLATEX...AND WILL PROBABLY CONTINUE TO GRADUALLY ADVECT NORTHWARD THROUGH THE OZARKS BY LATE TONIGHT. ELEVATED MOISTURE RETURN IN ZONE OF ISENTROPIC ASCENT TO THE NORTH OF THIS REGION IS ALREADY OCCURRING ...WITH WEAK CONVECTIVE DEVELOPMENT EVIDENT IN RADAR/SATELLITE IMAGERY ACROSS PARTS OF NORTHEAST KANSAS/SOUTHEAST NEBRASKA/ NORTHWEST MISSOURI. HOWEVER...CONVECTION IS STILL CAPPED BY A RELATIVELY WARM 850-700 MB LAYER. THIS MAY REMAIN THE CASE AT LEAST ANOTHER FEW HOURS...BUT CLOSER TO 00Z...AND MORE LIKELY THEREAFTER...IT APPEARS STRONGER MID-LEVEL COOLING/LIFT WILL BE SUFFICIENT FOR AN INCREASE IN THUNDERSTORM ACTIVITY ACROSS THE MID/ LOWER MISSOURI VALLEY. SOME HAIL...POSSIBLY GUSTY WINDS...MAY ACCOMPANY STRONGER CELLS...BUT WITH MOST UNSTABLE CAPE EXPECTED AT OR BELOW 500 J/KG...IT APPEARS MOST STORMS SHOULD REMAIN BELOW SEVERE LIMITS. OTHERWISE...A MORE GRADUAL MID-LEVEL COOLING AND CONTINUED INCREASE IN LOW-LEVEL MOISTURE ARE EXPECTED TO EVENTUALLY SUPPORT A FEW THUNDERSTORMS IN BROADER-SCALE LOW-LEVEL WARM ADVECTION REGIME THROUGH MUCH OF THE MISSISSIPPI VALLEY. THIS MAY NOT OCCUR UNTIL LATE THIS EVENING/OVERNIGHT. ...PACIFIC NORTHWEST... COLDER MID-LEVEL AIR MASS...AND COLDER EQUILIBRIUM TEMPERATURES... ASSOCIATED WITH UPPER TROUGH ARE SPREADING TOWARD NORTHWEST WASHINGTON/VANCOUVER ISLAND...WHERE IT APPEARS BEST POTENTIAL FOR AN ISOLATED THUNDERSTORM OR TWO EXISTS LATE TODAY/TONIGHT. ..KERR.. 12/11/2006  From swody1 at goshenarc.org Tue Dec 12 00:57:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Dec 2006 19:57:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120058 SWODY1 SPC AC 120056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST MON DEC 11 2006 VALID 120100Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID MO/MS VLYS SWD TO NE TX/NRN LA... STRONGER LARGE SCALE ASCENT/STEEP MID-TROPOSPHERIC LAPSE RATES ASSOCD WITH A LEAD MID-LEVEL JETLET WILL CONTINUE TO SPREAD NEWD THROUGH THE MID-MO VLY INTO CNTRL/SRN IA THIS EVE. LATEST ACARS SOUNDING FROM KMCI SAMPLED A WARM NOSE AROUND 810 MB...BUT WITH MODEST LAPSE RATES ABOVE. RUC FORECAST SOUNDINGS SUGGEST THAT LAPSE RATES ALOFT WILL CONTINUE TO STEEPEN WITH TIME AS THE PRIMARY UPPER SYSTEM APPROACHES THE REGION AND MUCAPES COULD REACH AS HIGH AS 500-700 J/KG. THIS WAS ALREADY EVIDENCED BY THE 00Z TOP SOUNDING WHERE H85-H5 LAPSE RATES WERE IN EXCESS OF 8 DEG C PER KM AND MUCAPE OF 557 J/KG. AS A RESULT...SPORADIC TSTMS WILL CONTINUE TO EVOLVE FROM EXTREME SERN NEB AND NERN KS NEWD INTO NWRN MO AND CNTRL/SRN IA THIS EVE WITH SOME TENDENCY TO DEVELOP SWD INTO NRN/CNTRL MO TO THE N OF INTERSTATE 70. GIVEN MAGNITUDE OF LAPSE RATES AND FAVORABLE CAPE-BEARING SHEAR...A FEW OF THE STRONGER STORMS MAY PRODUCE HAIL OR PERHAPS GUSTY WINDS. ELSEWHERE...WARM CONVEYOR BELT CONTINUES TO BE WELL-ESTABLISHED FROM THE WRN GULF COAST NEWD INTO THE MIDWEST THIS EVENING. SRN PERIPHERY OF THE EJECTING UPPER SYSTEM WILL BEGIN TO IMPINGE ON THE WRN PARTS OF THIS CONVEYOR LATER THIS EVENING/OVERNIGHT. 00Z LZK RAOB SUGGEST THAT LAPSE RATES WERE RATHER POOR...BUT AS THE COLDER TEMPERATURES ALOFT SPREAD EWD AND Q-VECTOR CONVERGENCE ARRIVES AFTER 06Z...THERE WILL BE AN INCREASING THREAT FOR TSTMS...ESPECIALLY FROM SERN MO SWD INTO CNTRL AR AND NRN LA. STRONGER STORMS MAY CONTAIN SMALL HAIL...BUT NO ORGANIZED SEVERE TSTMS ARE EXPECTED ALONG SRN PARTS OF THE TSTM OTLK. ..RACY.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 05:33:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 00:33:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120534 SWODY1 SPC AC 120532 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST MON DEC 11 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...LWR OH VLY AND MID-SOUTH... COMPLEX UPPER WAVE LOCATED OVER THE PLAINS EARLY ON TUESDAY WILL TRANSLATE NEWD INTO THE GRTLKS AND THE OH/TN VLYS THROUGH TUESDAY NIGHT. THE INITIAL LEAD WAVE MOVING THROUGH THE CORN BELT EARLY IN THE DAY WILL DAMPEN AS THE CORE OF THE UPPER LOW BEGINS TO ROTATE EWD TOWARD THE UPPER GRTLKS DURING THE AFTN. STRONGER LARGE SCALE HEIGHT FALLS WILL OCCUR FROM THE MID-SOUTH INTO THE LWR OH VLY DURING THE DAY. WARM CONVEYOR CONTINUES TO TRANSPORT MOISTURE NEWD FROM THE GULF OF MEXICO INTO THE MIDWEST...BUT LAPSE RATES ALOFT HAVE REMAINED POOR. H7-H5 LAPSE RATES WILL IMPROVE TUE MORNING AND AS STRONGER Q-VECTOR CONVERGENCE ASSOCD WITH THE MAIN IMPULSE LIFTS NEWD...THE BACK EDGE OF THE SHOWERS MAY INTENSIFY INTO TSTMS. MUCAPES ARE FORECAST TO REACH AROUND 500 J/KG ACROSS PORTIONS OF THE LWR OH VLY/MID-SOUTH FROM LATE TUE MORNING INTO THE AFTN. MAGNITUDE OF MID-LEVEL LAPSE RATES AND FAVORABLE SHEAR IN THE CAPE BEARING LAYER MAY CONTRIBUTE TO ISOLD STRONGER STORMS CAPABLE OF PRODUCING HAIL OR GUSTY WINDS. TSTMS PROBABILITIES WILL DECREASE RAPIDLY AFTER 00Z WED ACROSS THE OH/TN VLYS AS THE UPPER SYSTEM BEGINS TO LIFT NEWD BEYOND THE GULF MOISTURE PLUME. ..RACY.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 12:51:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 07:51:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121252 SWODY1 SPC AC 121250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 AM CST TUE DEC 12 2006 VALID 121300Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...MS/OH VALLEY REGION... WATER VAPOR IMAGERY AND PROFILER DATA SHOW A MID LEVEL SHORTWAVE TROUGH OVER NE TX/SE OK THIS MORNING WHICH WILL ROTATE NEWD TO THE OH VALLEY BY TONIGHT. AN ASSOCIATED SURFACE TROUGH/WEAK COLD FRONT WILL MOVE EWD FROM E TX AND WRN AR TO THE MS RIVER BY THIS EVENING...AND CONTINUE EWD INTO THE TN/OH VALLEYS TONIGHT WHILE BECOMING MORE DIFFUSE. A NARROW CORRIDOR OF MOISTURE RETURN /BOUNDARY LAYER DEWPOINTS OF 56-64 F/ IS PRESENT IN ADVANCE OF THE SURFACE TROUGH AND SW OF THE LARGE RIDGE OVER THE ATLANTIC COAST. THIS MOISTURE WILL SPREAD NEWD TO THE LOWER OH VALLEY AND EWD ACROSS MS/WRN TN DURING THE DAY...BUT THE WARM SECTOR WILL REMAIN NARROW. REGIONAL SOUNDINGS SUGGEST THAT THE STEEPER MID LEVEL LAPSE RATES ARE CONFINED TO THE MID LEVEL THERMAL TROUGH...WHICH IS LARGELY W/NW OF THE RICHER LOW-LEVEL MOISTURE. THIS CONFIGURATION IS AND WILL CONTINUE TO LIMIT THE DEGREE OF INSTABILITY ACROSS THE MS AND LOWER OH VALLEYS TODAY. THE MAJORITY OF THE CONVECTION TODAY WILL REMAIN IN A PRE-FRONTAL BAND...FOCUSED BY LARGE SCALE ASCENT/LOW-LEVEL WAA TO THE E AND NE OF THE SURFACE-BASED INSTABILITY. ASCENT ALONG THE SURFACE TROUGH/WEAK COLD FRONT SHOULD BE RELATIVELY SHALLOW/WEAK...AND THUNDERSTORM DEVELOPMENT SHOULD BE ISOLATED AT BEST ALONG THE SURFACE TROUGH LATER TODAY. IF THUNDERSTORMS DEVELOP...MID LEVEL LAPSE RATES NEAR 7.5 C/KM AND 500 MB TEMPERATURES COLDER THAN -20 C COULD SUPPORT A FEW STORMS WITH MARGINALLY SEVERE HAIL DURING THE AFTERNOON/EARLY EVENING FROM NE AR/WRN TN INTO SRN IL/SW INDIANA. FARTHER S ACROSS LA/MS IN THE MOIST SECTOR...THE SEVERE STORM THREAT WILL BE LIMITED BY POOR MID LEVEL LAPSE RATES AND WEAKENING LOW-LEVEL FLOW/SHEAR DURING THE DAY. ..THOMPSON.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 16:21:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 11:21:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121622 SWODY1 SPC AC 121620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST TUE DEC 12 2006 VALID 121630Z - 131200Z ...NO SVR TSTM AREAS FORECAST... DEEP UPPER TROUGH CONTINUES TO MOVE SLOWLY EASTWARD ACROSS THE CENTRAL UNITED STATES THIS MORNING...WITH PRIMARY SURFACE LOW LIFTING NORTHWARD ACROSS MN. MAIN SURFACE COLD FRONT EXTENDS SOUTHWARD FROM LOW ACROSS CENTRAL MO/AR INTO NORTHEAST TX. NUMEROUS SHOWERS/THUNDERSTORMS HAVE BEEN OCCURRING AHEAD OF FRONT...BUT HAVE NOW MOVED SUFFICIENTLY EASTWARD TO ALLOW BREAKS IN THE CLOUDS ALONG FRONT. WATER VAPOR IMAGERY AND MODEL GUIDANCE SUGGEST THAT STEEP LAPSE RATES AND AT LEAST WEAK LARGE SCALE ASCENT WILL OVERSPREAD THE FRONTAL ZONE THIS AFTERNOON. THIS MAY ALLOW ISOLATED SHOWERS AND THUNDERSTORMS TO RE-DEVELOP ALONG THE FRONT OVER CENTRAL IL...SOUTHEAST MO...INTO EASTERN AR. GIVEN SUFFICIENT DAYTIME HEATING...THE STRONGEST STORMS COULD PRODUCE HAIL AND GUSTY WINDS. ..HART.. 12/12/2006  From swody1 at goshenarc.org Tue Dec 12 19:55:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 14:55:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121956 SWODY1 SPC AC 121954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0154 PM CST TUE DEC 12 2006 VALID 122000Z - 131200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFIED TROUGH...WITH SEVERAL EMBEDDED SMALLER SCALE IMPULSES... IS ALREADY BEGINNING TO LIFT OUT OF THE MISSISSIPPI VALLEY...AS STRONG HIGH-LEVEL JET NOSES TOWARD THE PACIFIC NORTHWEST. LACK OF SIGNIFICANT SURFACE CYCLOGENESIS AND WEAK RETURN FLOW...OFF A SLOWLY MODIFYING BOUNDARY LAYER OVER THE GULF OF MEXICO... CONTINUES TO MINIMIZE CONVECTIVE POTENTIAL. AND...THIS IS GENERALLY EXPECTED TO REMAIN THE CASE THROUGH THE REMAINDER OF THIS FORECAST PERIOD. ...LOWER MISSISSIPPI VALLEY/CENTRAL GULF COAST... THE MOST SIGNIFICANT ONGOING CONVECTION...INCLUDING SCATTERED THUNDERSTORMS...IS SHIFTING EASTWARD THROUGH THE CENTRAL GULF STATES...IN SOUTHERN PORTION OF ELONGATED ZONE OF LOW-LEVEL WARM ADVECTION/ISENTROPIC ASCENT AHEAD OF UPPER TROUGH AXIS. THIS IS WHERE MOISTURE RETURN HAS BEEN MAXIMIZED ALONG PRE-FRONTAL SOUTHERLY LOW-LEVEL JET AXIS...CONTRIBUTING TO WEAK CAPE. MID-LEVEL LAPSE RATES ARE GENERALLY WEAK...HOWEVER...AND LOW-LEVEL FLOW EAST OF THE LOWER MISSISSIPPI VALLEY IS BEGINNING TO WEAKEN AS 70-90 KT MID-LEVEL JET STREAK LIFTS OUT OF THE LOWER MISSISSIPPI VALLEY INTO THE LOWER OHIO VALLEY. THUNDERSTORM ACTIVITY IS EXPECTED TO DIMINISH ACROSS MISSISSIPPI/ALABAMA LATE THIS AFTERNOON AS LARGE-SCALE ASCENT DECREASES. ...MIDDLE MISSISSIPPI/LOWER OHIO VALLEYS... AN IMPULSE ASSOCIATED WITH THE JET STREAK IS LIFTING NORTHEAST OF THE OZARK PLATEAU. STRONGER FORCING WITH THIS FEATURE IS BEGINNING TO OVERSPREAD NARROW LOW-LEVEL THERMAL RIDGE ACROSS EASTERN MISSOURI INTO SOUTHERN/CENTRAL ILLINOIS...WHERE HEATING OF BOUNDARY LAYER WITH LOWER/MID 50S SURFACE DEW POINTS HAS OCCURRED BENEATH DRY SLOT. MIXED LAYER CAPE OF 250-500 J/KG IS WEAK...BUT LAPSE RATES ARE FAIRLY STEEP...AND CONVECTIVE INSTABILITY PRESENT IN SOUNDINGS WILL PROBABLY BE SUPPORTIVE OF A FEW STORMS WHICH MAY PRODUCE HAIL/WIND GUSTS APPROACHING OR BRIEFLY EXCEED SEVERE LIMITS. A BROKEN LINE OF STORMS APPEARS POSSIBLE ALONG/AHEAD OF THE COLD FRONT LATE THIS AFTERNOON AND EARLY EVENING...BEFORE THE FRONT PROGRESSES THROUGH THE REMAINDER OF THE MORE STRONGLY HEATED BOUNDARY LAYER. THEREAFTER...POTENTIAL WILL DIMINISH DEEPER INTO THE LOWER OHIO VALLEY. ...UPPER MISSISSIPPI VALLEY/GREAT LAKES... PRE-FRONTAL DESTABILIZATION HAS BEEN EVEN WEAKER NORTHWARD INTO PARTS OF THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES. BUT...IT MAY STILL BE SUFFICIENT FOR SCATTERED THUNDERSTORM ACTIVITY... PRIMARILY AS MID-LEVEL TROUGH AXIS SHIFTS ACROSS WISCONSIN LATE THIS AFTERNOON INTO THE EVENING HOURS. AS FORCING CONTINUES EASTWARD ACROSS THE GREAT LAKES OVERNIGHT...COOLER LOW-LEVEL ENVIRONMENT WITH WEAKER LOW-LEVEL LAPSE RATES ARE EXPECTED TO RESULT IN DIMINISHING CONVECTIVE POTENTIAL. ..KERR.. 12/12/2006  From swody1 at goshenarc.org Wed Dec 13 00:48:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Dec 2006 19:48:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130048 SWODY1 SPC AC 130046 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0646 PM CST TUE DEC 12 2006 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...MIDWEST/LWR OH VLY... STRONGER LARGE SCALE ASCENT ASSOCD WITH THE UPPER SHORTWAVE TROUGH WAS SPREADING ENEWD INTO INDIANA AND LWR MI THIS EVENING. THIS WAS SUPPORTING A BAND OF TSTMS ALONG A COLD FRONT THAT WILL MOVE ENEWD ACROSS LWR MI...IND AND KY THROUGH THE NIGHT. BUOYANCY IS LIMITED...BUT 00Z DVN/ILX RAOBS SAMPLED VERY STEEP MID-LEVEL LAPSE RATES WITHIN THE CORE OF THE UPPER SYSTEM. THIS COMBINED WITH MODEST LOW-LEVEL LAPSE RATES FROM THE HEATING CYCLE HAS CONTRIBUTED TO NARROW AXIS OF MUCAPES OF A COUPLE HUNDRED J/KG IMMEDIATELY DOWNSTREAM FROM THE FRONT ACROSS SWRN LWR MI TO WRN KY. TSTMS PROBABILITIES WILL CONTINUE THROUGH THIS EVENING AHEAD OF THE FRONT...BUT EWD EXTENT WILL LIKELY BE MODULATED BY LESS FAVORABLE THERMODYNAMIC PROFILES ACROSS THE MID-UPPER OH VLY. IT APPEARS THAT THE INTENSITY OF STORMS HAS PEAKED AND NO WIDESPREAD SVR WEATHER IS ANTICIPATED. ...CNTRL GULF COASTAL REGION... WATER VAPOR SHOWS A SECONDARY JET STREAK MIGRATING ACROSS THE DEEP S THIS EVE WITH RIGHT-ENTRANCE REGION DERIVED LARGE SCALE UVV SUPPORTING CONVECTION ACROSS AL AND COASTAL MS/LA. BETTER QUALITY BOUNDARY LAYER MOISTURE HUGGING THE COAST VCNTY KMOB APPEARS TO BE SUFFICIENT FOR PARCELS TO REACH INTO THE ICE PRODUCING LAYER FOR LIGHTNING. BUT...00Z JAN/LCH/SHV SOUNDINGS AND LATEST KBTR/KLFT ACARS SUGGEST THAT WARMING IN THE H7-H5 LAYER WILL SPREAD EWD LATER THIS EVENING...MAKING THE ENVIRONMENT INCREASINGLY HOSTILE TO SUSTAINING TSTMS. ..RACY.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 05:34:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 00:34:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130534 SWODY1 SPC AC 130532 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST TUE DEC 12 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... TSTM POTENTIAL WILL REMAIN LOW ACROSS THE COUNTRY ON WED. THE UPPER DISTURBANCE CURRENTLY MOVING THROUGH THE OH VLY WILL BEGIN TO LOOSE AMPLITUDE ON WED AS A MORE POWERFUL NRN STREAM EMERGES ACROSS THE PAC NW TO THE NRN ROCKIES. ISOLD LIGHTNING WILL BE LIKELY ACROSS NWRN WA WHERE A STEEP LAPSE RATES ENVIRONMENT SPREADS EWD TO THE NORTH OF A POWERFUL JET. ELSEWHERE...SRN PERIPHERY OF THE EJECTING OH VLY TROUGH MAY INTERACT WITH MODEST BOUNDARY LAYER MOISTURE SITUATED ALONG THE SERN SEABOARD WED AFTN. TSTM POTENTIAL WILL LIKELY STAY OFFSHORE WHERE STRONGER INSTABILITY WILL RESIDE...BUT ONE OR TWO STRIKES CANNOT BE RULED OUT INVOF THE NC OUTER BANKS. HERE...COVERAGE IS EXPECTED TO REMAIN LESS THAN 10 PERCENT CLOSER TO SHORE. ..RACY.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 13:02:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 08:02:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131303 SWODY1 SPC AC 131301 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0701 AM CST WED DEC 13 2006 VALID 131300Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A LARGELY ZONAL FLOW REGIME IS EXPECTED OVER THE CONUS THROUGH TOMORROW...WITH THE PRIMARY JET FROM THE PAC NW TO THE GREAT LAKES. AN INITIAL MID LEVEL SHORTWAVE TROUGH OVER THE APPALACHIANS THIS MORNING WILL WEAKEN AND MOVE NEWD OVER THE MID ATLANTIC/NEW ENGLAND BY EARLY TONIGHT. THIS MID LEVEL WAVE WILL BE ACCOMPANIED BY A DIFFUSE SURFACE TROUGH/WEAK FRONT WHICH WILL BECOME EVEN LESS DEFINED WITH TIME. MEANWHILE...THE LOW LEVELS HAVE WARMED/MOISTENED ALONG AND SE OF A COASTAL TROUGH OFF GA AND THE CAROLINAS. INITIALLY SHALLOW CONVECTION ALONG THIS TROUGH SHOULD DEEPEN DURING THE DAY...WITH THE THREAT FOR THUNDERSTORMS EXPECTED TO INCREASE JUST OFFSHORE. MORE ISOLATED CONVECTION...AND PERHAPS A FEW LIGHTNING STRIKES...WILL BE POSSIBLE JUST INLAND OF THE SE ATLANTIC COAST THROUGH THIS EVENING. THUNDERSTORM COVERAGE SHOULD REMAIN RATHER SPARSE GIVEN MARGINAL INSTABILITY AND RATHER WEAK FORCING FOR ASCENT. A STRONG TROUGH IS MOVING INLAND OVER WA AND BRITISH COLUMBIA...AND THIS SYSTEM WILL PROGRESS QUICKLY EWD TOWARD THE NRN HIGH PLAINS BY EARLY THURSDAY. RELATIVELY STEEP LAPSE RATES AND COLD MID LEVEL TEMPERATURES COULD SUPPORT ISOLATED THUNDERSTORMS THE FIRST HALF OF THE DAY...BEFORE THE THUNDERSTORM THREAT ENDS IN ASSOCIATION WITH SHORTWAVE RIDGING BY THIS EVENING. OTHERWISE...A WEAK MID LEVEL TROUGH FROM NW MEXICO INTO NM WILL MOVE SEWD TOWARD THE LOWER RIO GRANDE VALLEY LATE IN THE PERIOD. GRADUAL MOISTENING/ DESTABILIZATION NEAR THE LOWER TX COAST COULD SUPPORT AN ISOLATED THUNDERSTORM THREAT BY EARLY THURSDAY JUST OFFSHORE. ..THOMPSON.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 16:11:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 11:11:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131610 SWODY1 SPC AC 131608 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1008 AM CST WED DEC 13 2006 VALID 131630Z - 141200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH IS IN PLACE ACROSS MOST OF THE NATION TODAY...WITH WATER VAPOR IMAGERY SHOWING SEVERAL EMBEDDED FEATURES TRACKING ACROSS THE COUNTRY. ONE STRONG UPPER JET AND ASSOCIATED VORT MAX ARE MOVING ASHORE ALONG THE WA COAST THIS MORNING. STRONG ONSHORE FLOW AND COLD TEMPERATURES ALOFT WILL MAINTAIN A RISK OF ISOLATED THUNDERSTORMS OVER THIS REGION THROUGH AFTERNOON. WEAK SURFACE BAROCLINIC ZONE IS MOVING SLOWLY SOUTHEASTWARD ACROSS THE CAROLINAS. SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP AHEAD OF THIS BOUNDARY...ESPECIALLY OVER THE GULF STREAM IMMEDIATELY OFFSHORE. NEVERTHELESS...MODELS SUGGEST WEAK BUT SUFFICIENT CAPE VALUES FOR THE THREAT OF ISOLATED THUNDERSTORMS ALONG THE IMMEDIATE CAROLINA COAST...INTO PARTS OF SOUTHEAST GA AND NORTHEAST FL. NO SEVERE STORMS ARE ANTICIPATED. ..HART.. 12/13/2006  From swody1 at goshenarc.org Wed Dec 13 19:19:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 14:19:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131920 SWODY1 SPC AC 131918 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0118 PM CST WED DEC 13 2006 VALID 132000Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SOUTH ATLANTIC COAST... SOUTHERN PERIPHERY OF WEAKENING LARGE-SCALE TROUGH HAS SHIFTED EAST OF THE SOUTH CENTRAL APPALACHIANS...AND IS EXPECTED TO PROGRESS OFF SOUTHERN MID ATLANTIC COASTAL AREAS EARLY THIS EVENING. FORCING MAY STILL EVENTUALLY SUPPORT SCATTERED THUNDERSTORMS. BUT...THE BOUNDARY LAYER OVER THE COASTAL WATERS IS STILL IN THE PROCESS OF MODIFYING...AND IT APPEARS MOST LIKELY THAT THIS WILL OCCUR WELL OFFSHORE...PROBABLY NEAR THE GULF STREAM. ...PACIFIC NORTHWEST... INCREASINGLY ANTICYCLONIC FLOW IS DEVELOPING NORTHEASTWARD TOWARD THE NORTHERN PACIFIC COAST...AND RISK OF THUNDERSTORMS ALREADY APPEARS TO BE DIMINISHING. POTENTIAL IS EXPECTED TO BECOME NEGLIGIBLE BY THE 14/00-03Z TIME FRAME...AS LOW-LEVEL ONSHORE FLOW WEAKENS AND TEMPERATURES IN THE LOWER/MID TROPOSPHERE WARM... STABILIZING LAPSE RATES. ..KERR.. 12/13/2006  From swody1 at goshenarc.org Thu Dec 14 00:35:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Dec 2006 19:35:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140035 SWODY1 SPC AC 140032 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 PM CST WED DEC 13 2006 VALID 140100Z - 141200Z ...NO TSTM AREAS FORECAST... ...WA... ISOLATED CG LIGHTNING STRIKES HAVE BEEN OCCURRING ON THE OLYMPIC PENINSULA OVER THE PAST COUPLE OF HOURS. THIS ACTIVITY IS PROBABLY ASSOCIATED WITH INTENSE OROGRAPHIC FORCING AND WEAK DESTABILIZATION IN MOIST ONSHORE FLOW REGIME. SLIGHT RIDGING/WARMING ALOFT IS FORECAST ACROSS THE REGION THE REMAINDER OF TONIGHT AND THIS SHOULD GENERALLY LIMIT TSTMS DESPITE A CONTINUATION OF MOIST ONSHORE FLOW. ...FL... WEAK WARM AIR ADVECTION/ISENTROPIC LIFT WILL PERSIST ACROSS RESIDUAL FRONTAL ZONE OVER NRN FL. EVENING SOUNDINGS EXHIBIT A MOIST AIR MASS SOUTH OF THE FRONT OVER CNTRL SECTIONS OF THE PENINSULA. A VARIETY OF MODEL GUIDANCE SUGGESTS SOME POTENTIAL WILL EXIST FOR WIDELY SCATTERED CONVECTION ACROSS THE REGION TONIGHT. HOWEVER...WEAK LAPSE RATES AND LIMITED FORCING SHOULD KEEP ANY TSTM ACTIVITY QUITE ISOLATED. ..CARBIN.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 05:45:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 00:45:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140546 SWODY1 SPC AC 140543 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1143 PM CST WED DEC 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... FAST-MOVING WAVE TRAIN WILL CONTINUE ACROSS THE NRN STATES THIS PERIOD AS A LEAD IMPULSE...CURRENTLY MOVING ACROSS THE NRN PRAIRIES...SPREADS EWD AND AMPLIFIES OVER THE GREAT LAKES THROUGH EARLY FRIDAY. ANOTHER STRONG STORM SYSTEM...NOW MAKING STEADY EWD PROGRESS ACROSS THE ERN PACIFIC...WILL MAKE IT TO THE NORTHWEST COAST TODAY WITH STRONG MID LEVEL HEIGHT FALLS DEVELOPING INLAND TO THE NRN GREAT BASIN AND NRN ROCKIES THROUGH LATE TONIGHT. SOUTH OF THE FASTER MID LEVEL FLOW...A BROAD UPPER TROUGH AND MID LEVEL SHEAR ZONE IS FORECAST TO EVOLVE ACROSS MEXICO AND THE NWRN GULF. WEAK DISTURBANCES EMANATING FROM THIS TROUGH WILL TRANSLATE EWD OVER THE ERN GULF AND FL TODAY...LIKELY ENHANCING ASCENT NEAR AND SOUTH OF RESIDUAL DEEP-LAYER FRONTAL ZONE. ...FL... LOW LEVEL ELY FETCH OFF THE ATLANTIC WILL MAINTAIN 65-70F DEWPOINTS ACROSS CNTRL AND SRN FL TODAY. DIURNAL HEATING SHOULD CONTRIBUTE TO THE DEVELOPMENT OF INSTABILITY WITH FORECAST SOUNDINGS DEPICTING MUCAPE OF 800-1200 J/KG POSSIBLE. GIVEN WEAK CAP AND POSSIBILITY OF MODEST BACKGROUND ASCENT FROM SRN STREAM IMPULSES...EXPECT AT LEAST SCATTERED TSTM DEVELOPMENT THROUGH THE AFTERNOON. EFFECTIVE BULK SHEAR MAGNITUDES OF AROUND 30KT COULD SUPPORT ISOLATED PERSISTENT MULTICELLULAR STORMS...PERHAPS GENERATING GUSTY WINDS...BUT LAPSE RATES AND LACK OF STRONGER LOW LEVEL FLOW SHOULD NEGATE HIGHER PROBABILITY SEVERE THREAT. ...PAC NW... ONSHORE FLOW AND WARM AIR ADVECTION WILL INTENSIFY THROUGH THE DAY FROM NRN CA ACROSS WRN WA AHEAD OF THE NEXT STRONG SHORT WAVE TROUGH APPROACHING THE COAST. INSTABILITY WILL LIKELY REMAIN TOO MARGINAL TO SUPPORT CG LIGHTNING UNTIL AFTER THE PASSAGE OF THE STRONGER DYNAMIC FORCING ASSOCIATED WITH THE UPPER TROUGH. STRONG OROGRAPHIC FORCING AND LOWERING STATIC STABILITY ASSOCIATED WITH MID LEVEL COLD AIR ADVECTION IN THE WAKE OF THE STRONGER HEIGHT FALLS SHOULD LEAD TO AT LEAST WIDELY SCATTERED TSTM ALONG THE COAST AND INTO THE COAST RANGES THROUGH TONIGHT. ...UPPER MS VALLEY TO GREAT LAKES... A FAST-MOVING POCKET OF STRONG DYNAMIC FORCING AND WEAK DESTABILIZATION ON THE NOSE OF NARROW BUT INTENSE JET STREAK WILL CONTINUE TO SWEEP EAST FROM SD TO MN THROUGH DAYBREAK. THIS FEATURE HAS SPAWNED SPORADIC LIGHTNING WITH A FEW HIGH WIND GUSTS OBSERVED AT THE SURFACE. NAM-WRF HINTS THAT ISOLATED CONVECTION MAY PERSIST AS THIS SYSTEM MOVES EAST AND AMPLIFIES THROUGH THE DAY. HOWEVER...LACK OF GREATER INSTABILITY AND FAST MOVEMENT OF THE IMPULSE SHOULD LIMIT LIGHTNING COVERAGE TO LESS THAN 10 PERCENT ACROSS THE REGION. ..CARBIN.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 13:03:25 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 08:03:25 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141302 SWODY1 SPC AC 141300 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0700 AM CST THU DEC 14 2006 VALID 141300Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MODERATELY AMPLIFIED BUT PROGRESSIVE REGIME WILL PREVAIL ACROSS NOAM THROUGH FRIDAY...WITH DOMINANT NRN STREAM JET. A STRONG IMPULSE IN THE JET OVER THE NE PACIFIC...CROSSING 140W...WILL CONTINUE E OR SLIGHTLY N OF E INTO CANADIAN RCKYS/WRN MT BY 12Z FRIDAY. THE WEAKER SRN BRANCH...LOWER AMPLITUDE DISTURBANCE NOW OVER THE LWR RIO GRANDE SHOULD MOVE MORE SLOWLY INTO THE WRN GULF. ...CNTRL/SRN FL... LOW LEVEL ESE FLOW OFF THE ATLANTIC WILL MAINTAIN 65-70F DEWPOINTS ACROSS CNTRL AND SRN FL TODAY...WHERE MODEST DAYTIME HEATING SHOULD BOOST MUCAPE TO AROUND 1000 J/KG. LARGE SCALE FORCING FOR ASCENT WILL REMAIN WEAK WITH WEAK UPR LEVEL RIDGING DOWNSTREAM FROM RIO GRANDE TROUGH. BUT WITH LIMITED INHIBITION...EVEN WEAK LOW LEVEL CONVERGENCE INVOF OF OLD FRONTAL ZONE MAY SUPPORT CONVECTIVE DEVELOPMENT DEEP ENOUGH TO YIELD THUNDER. 30 KT DEEP WLY SHEAR MAY ALSO SUPPORT A FEW LONGER-LIVED UPDRAFTS...BUT WEAK LAPSE RATES/LOW LEVEL FLOW SHOULD LIMIT THREAT FOR SEVERE. ...WRN WA/ORE... COLD FRONT ASSOCIATED WITH WELL-DEFINED NE PACIFIC FRONTAL WAVE WILL MOVE ACROSS WRN WA AND ORE DURING THE MID TO LATE EVENING. ATTENDANT PRECIP BAND MAY CONTAIN SUFFICIENT VERTICAL DEVELOPMENT TO SUPPORT ISOLATED EMBEDDED THUNDER. A GREATER LIKELIHOOD FOR THUNDER WILL...HOWEVER...LIKELY AWAIT ARRIVAL OF FAST...COOL AND UNSTABLE POST-FRONTAL CYCLONIC FLOW REGIME LATER TONIGHT/EARLY FRIDAY... MAINLY OVER THE WA/ORE CASCADES. ...UPR MS VLY/UPR GRT LKS... MID LEVEL LAPSE RATES SHOULD GRADUALLY DIMINISH ALONG PATH OF FAST-MOVING NRN STREAM IMPULSE CROSSING THE UPR MS VLY THIS MORNING. SOME CONVECTION LIKELY WILL PERSIST WITH FEATURE AS IT MOVES FARTHER E AND AMPLIFIES ACROSS SRN MN/SRN WI/NRN IA/LK MI AND WRN LWR MI LATER TODAY. LIMITED DEGREE OF INSTABILITY SHOULD...HOWEVER...KEEP ANY ASSOCIATED LIGHTNING COVERAGE ISOLATED DESPITE AMPLIFICATION OF UPR SYSTEM. ...S TX... LOW CLOUDS SHOULD LIMIT HEATING/HELP MAINTAIN CAP...THEREBY PRECLUDING WIDESPREAD DEEP CONVECTIVE DEVELOPMENT AS WEAK UPR TROUGH CROSSES REGION LATER TODAY. ..CORFIDI.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 16:04:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 11:04:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141604 SWODY1 SPC AC 141602 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1002 AM CST THU DEC 14 2006 VALID 141630Z - 151200Z ...NO SVR TSTM AREAS FORECAST... STRONG SYSTEMS CONTINUE TO MOVE RAPIDLY EWD ACROSS NRN U.S. AND SRN CANADA. S OF 40N...CONUS UNDER THE INFLUENCE OF A WEAKER SUBTROPICAL WAVE TRAIN. SURFACE RIDGING FROM MID ATLANTIC STATES TO SRN PLAINS CONFINING ANY SIGNIFICANT LOW LEVEL MOISTURE AND INSTABILITY TO FAR S TX AND THE FL PENINSULA. AREA OF GREATEST THUNDERSTORM POTENTIAL THIS FORECAST PERIOD SHOULD BE SRN FL WHERE LOW LEVEL SELYS HAVE IMPORTED A MOIST BUT ONLY MARGINALLY UNSTABLE AIR MASS. WITH APPROACH OF THE WEAK EMBEDDED S/WV TROUGH NOTED IN WV OVER SRN TX...THUNDERSTORM POTENTIAL SHOULD INCREASE THIS AFTERNOON SRN FL. LIMITED HEATING...WEAK LAPSE RATES AND MARGINAL SHEAR PRECLUDES ANY SEVERE THUNDERSTORM THREAT. NEXT IN CURRENT SERIES OF DEEP CYCLONES MOVES ACROSS VANCOUVER ISLAND THIS EVENING BRINGING VERY STRONG WINDS INLAND PAC NW. WEAK INSTABILITY WILL LIMIT ANY THUNDERSTORM ACTIVITY TO COASTAL AREAS...PRIMARILY TONIGHT IN THE POST-FRONTAL ONSHORE FLOW. WHILE THERE COULD BE AN ISOLATED THUNDERSTORM FAR S TX THRU MID AFTERNOON...MOST OF THE ACTIVITY SHOULD REMAIN OVER THE GULF AND TO THE S AS THE MID LEVEL S/WV CURRENTLY CROSSING S TX MOVES ON TO THE E. ..HALES.. 12/14/2006  From swody1 at goshenarc.org Thu Dec 14 19:30:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 14:30:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141930 SWODY1 SPC AC 141928 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0128 PM CST THU DEC 14 2006 VALID 142000Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...PACIFIC NW... CURRENT WATER VAPOR IMAGERY INDICATES STRONG SHORT WAVE TROUGH APPROACHING VANCOUVER ISLAND AND THE WA COAST WITH A CLUSTER OF TSTMS OBSERVED NEAR 46N/131W AS OF 19Z PER OCEANIC LIGHTNING DATA. THIS FEATURE IS FORECAST TO MOVE ONTO THE COAST TONIGHT WITH LOW-LEVEL ONSHORE FLOW DEVELOPING IN WAKE OF ATTENDANT SURFACE PACIFIC FRONT. DESTABILIZATION ARISING FROM COOLING MID-LEVELS AND MOISTENING IN THE LOW-LEVELS COUPLED WITH FORCING ALONG FRONT AND WINDWARD SIDE OF COASTAL RANGE SHOULD SUPPORT A FEW EMBEDDED TSTMS OVERNIGHT ALONG AND SLIGHTLY INLAND OF THE COAST. ...DEEP S TX... LOW LATITUDE SHORT WAVE TROUGH CURRENTLY W OF BRO WILL CONTINUE EWD INTO THE GULF OF MEXICO TONIGHT. TSTMS ARE ONGOING THIS AFTERNOON ACROSS NRN PORTIONS OF NUEVO LEON/TAMAULIPAS MEXICO WITH ACTIVITY GRADUALLY DEVELOPING NEWD TOWARD THE RIO GRANDE VALLEY AND DEEP S TX. AMBIENT LOW-LEVEL AIR MASS REMAINS MOIST AND WEAKLY UNSTABLE WITH MLCAPES OF AROUND 500 J/KG. EXPECT THE THREAT OF TSTMS TO PERSIST THROUGH THE AFTERNOON...PERHAPS INTO EARLY EVENING BEFORE SHORT WAVE TROUGH AND ASSOCIATED STRONGER FORCING SHIFTS E OF REGION. ...CNTRL/SRN FL PENINSULA... AFTERNOON SURFACE OBSERVATIONS INDICATE WEAK LOW-LEVEL BOUNDARY FROM NEAR MLB SWWD TO SRQ WITH SEVERAL NW-SE ORIENTED CONFLUENCE ZONES PRESENT IN VISIBLE SATELLITE IMAGERY ALONG THE SERN FL COAST. LOW-LEVEL AIR MASS ALONG AND S OF THIS PRIMARY BOUNDARY IS QUITE MOIST WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S...HOWEVER WEAK LAPSE RATES ARE LIMITING OVERALL INSTABILITY. WATER VAPOR IMAGERY INDICATES A COUPLE OF WEAK IMPULSES PRECEDING S TX IMPULSE /SEE PREVIOUS SECTION/...ONE OF WHICH IS NEAR GRAND BAHAMA AND THE OTHER NEAR 24N/84W. WEAK FORCING ASSOCIATED WITH THESE FEATURES IN CONJUNCTION WITH THE MOIST LOW-LEVEL ENVIRONMENT IS EXPECTED TO REMAIN SUPPORTIVE OF ISOLATED/SCATTERED TSTMS ALONG AND S OF FRONTAL ZONE THIS AFTERNOON AND TONIGHT. ..MEAD.. 12/14/2006  From swody1 at goshenarc.org Fri Dec 15 00:59:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 14 Dec 2006 19:59:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150100 SWODY1 SPC AC 150058 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 PM CST THU DEC 14 2006 VALID 150100Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...FL... CONFLUENT LOW LEVEL SLY FLOW ACROSS SRN/CNTRL PARTS OF THE PENINSULA SHOULD CONTINUE TO SUPPORT SHOWERS AND PERHAPS OCNL TSTMS IN MOIST AIR MASS ACROSS FL TONIGHT. WEAK LAPSE RATES ARE PROBABLY LIMITING UPDRAFT STRENGTH AND CHARGE SEPARATION. HOWEVER...PASSAGE OF LOW AMPLITUDE DISTURBANCES ALOFT COULD STILL ENHANCE MESOSCALE FORCING AND STORM FORMATION IN MODESTLY SHEARED DEEP-LAYER FLOW. A COUPLE OF STRONGER STORMS WITH CG LIGHTNING STRIKES STILL APPEAR POSSIBLE THROUGH THE REMAINDER OF THE FORECAST PERIOD. ...NW COAST... ANOTHER POWERFUL CYCLONE WAS WRAPPING-UP NEAR VANCOUVER ISLAND THIS EVENING WITH 100-110KT MID LEVEL JET SPREADING ACROSS WRN WA/ORE. GIVEN POTENTIAL INSTABILITY AND INTENSE DYNAMIC FORCING/COOLING ALOFT...AND PERSISTENT MOIST ONSHORE AND UPSLOPE FLOWS...SPORADIC TSTMS SHOULD EXIST ACROSS THE REGION THROUGH THE NIGHT. ...S TX... A COUPLE OF STORMS HAVE FORMED BENEATH WEAK MID LEVEL TROUGH AXIS ACROSS THE MIDDLE TX COASTAL PLAIN THIS EVENING. DRY AIR IN THE MID LEVELS AND WARM AND MOIST BOUNDARY LAYER ARE CONTRIBUTING TO MUCAPE NEARING 2000 J/KG PER CRP EVENING SOUNDING. WITH LOSS OF DAYTIME HEATING IT IS UNCERTAIN HOW LONG CONVECTION CAN PERSIST. GIVEN THE WEAK BACKGROUND ASCENT ASSOCIATED WITH THE MID LEVEL WAVE AND LACK OF CAP EVIDENT ON THE CRP SOUNDING...EXPECT AT LEAST ANOTHER HOUR OR TWO OF TSTM POTENTIAL ACROSS THE REGION. ..CARBIN.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 05:45:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 00:45:46 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150546 SWODY1 SPC AC 150544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 PM CST THU DEC 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG HEIGHT FALLS ARE FORECAST TO SPREAD FROM THE INTERIOR NORTHWEST ACROSS THE NRN ROCKIES/HIGH PLAINS SWWD TO THE GREAT BASIN AS LARGE SCALE POSITIVE-TILT TROUGH EVOLVES ACROSS THE WEST THIS PERIOD. ANOTHER PROGRESSIVE SHORT WAVE TROUGH AND ASSOCIATED COLD FRONT WILL TRANSLATE EWD FROM THE GREAT LAKES TO OFF THE NEW ENGLAND COAST BY SATURDAY MORNING. BROAD UPPER TROUGH ACROSS TX/NRN MEXICO WILL DRIFT EWD OVER THE GULF TODAY AS RESIDUAL LARGE SCALE BAROCLINIC ZONE BISECTING FL SHIFTS GRADUALLY SOUTH. ...PACIFIC NW COAST... MOIST ONSHORE FLOW IN THE LOW-LEVELS COUPLED WITH VERY COLD MID-LEVEL TEMPERATURES OF -34C TO -38C AT 500 MB WILL AGAIN RESULT IN STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY. WITH STRONGER FORCING PASSING EAST OF THE REGION THROUGH THE DAY AND RIDGING ALOFT BUILDING INTO THE AREA BY TONIGHT...TSTM POTENTIAL SHOULD DIMINISH WITH TIME. ...SRN FL PENINSULA... MOIST AND UNSTABLE CONDITIONS ARE EXPECTED ALONG AND SOUTH OF WEAK LOW-LEVEL BOUNDARY PUSHING SWD THROUGH THE REGION. CONVERGENCE ALONG THIS FRONT...COUPLED WITH LITTLE OR NO CONVECTIVE INHIBITION... SHOULD RESULT IN TSTM ACTIVITY EMBEDDED WITHIN AREA OF SHOWERS. ...PA/NY/WRN NEW ENGLAND... WEAK INSTABILITY /MUCAPE 150-200 J PER KG/ IS FORECAST TO DEVELOP ACROSS PARTS OF THE NORTHEAST GIVEN UNSEASONABLY WARM/MOIST BOUNDARY LAYER AND COLD TEMPERATURES ALOFT. ASCENT ASSOCIATED WITH THE MIGRATORY SHORT WAVE TROUGH AND COLD FRONT SHOULD PROVE SUFFICIENT FOR SCATTERED CONVECTION AND POSSIBLY A FEW LIGHTNING STRIKES THROUGH THE AFTERNOON. SREF GUIDANCE INDICATES MOST LIKELY AREAS TO EXPERIENCE ISOLATED TSTM DEVELOPMENT ARE FROM ERN LAKE ONTARIO...SWD TO NERN PA...AND EWD ACROSS THE HUDSON VALLEY IN THE 19-22Z TIME FRAME. ISOLATED SMALL HAIL ALSO APPEARS POSSIBLE GIVEN POTENTIAL FOR STEEP LAPSE RATES AND LOW FREEZING LEVELS. ..CARBIN.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 13:02:03 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 08:02:03 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151302 SWODY1 SPC AC 151259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST FRI DEC 15 2006 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG BC/WRN MT TROUGH EXPECTED TO MOVE E/NE ACROSS AB/SK AND NRN MT TODAY BEFORE CONTINUING E INTO WRN MB SATURDAY MORNING. MID/UPR LEVEL FLOW OVER MUCH OF THE WRN AND CNTRL U.S WILL...HOWEVER...BACK WITH TIME AS POTENT SYSTEM NOW ALONG 140W AMPLIFIES AND CONTINUES E TOWARD THE CST. IN THE E...STLT LOOPS SUGGEST UPR GRT LKS SYSTEM WILL ALSO AMPLIFY TODAY AS IT CONTINUES E TOWARD THE N ATLANTIC CST. IN THE WEAKER SRN BRANCH...IMPULSE NOW OVER THE FAR WRN GULF EXPECTED TO DRIFT ONLY SLOWLY E THROUGH THE PERIOD. ...PAC NW INTO NRN RCKYS... STLT LOOPS SHOW COMPLEX VORTICITY PATTERN PRESENT ATTM OFF THE WA/ORE CST. ONE LOBE APPEARS TO BE DEVELOPING SE FROM AREA ABOUT 250 NM NW OF PDX...WITH AN UPSTREAM VORT LIKELY MORE CLOSELY ASSOCIATED WITH MAIN AMPLIFYING TROUGH CLOSE TO 43N/140W. DEEP...COLD CYCLONIC ONSHORE FLOW WITH MID-LEVEL TEMPERATURES AOB MINUS 35C WILL MAINTAIN THREAT FOR THUNDER ALONG THE CASCADES AND CSTL RANGES AS LEAD VORT MOVES ASHORE LATER TODAY. FARTHER E...MORE ISOLATED ACTIVITY MAY PERSIST FOR A FEW MORE HOURS INVOF FRONTAL BAND ASSOCIATED WITH BC/MT TROUGH. SHORTWAVE RIDGING DOWNSTREAM FROM AMPLIFYING TROUGH SHOULD REDUCE THUNDER POTENTIAL OVER WRN WA/ORE THIS EVENING. ...SRN FL... MOIST...SLIGHTLY UNSTABLE AND WEAKLY CAPPED ENVIRONMENT SHOULD ONCE AGAIN SUPPORT SHOWERS AND A FEW DIURNALLY-ENHANCED THUNDERSTORMS ALONG AND SOUTH OF WEAK BOUNDARY MOVING S ACROSS REGION. ...NRN PA/UPSTATE NY/WRN NEW ENGLAND... WEAK INSTABILITY /MUCAPE 150-200 J PER KG WITH TOTAL TOTALS AOA 52/ SHOULD DEVELOP OVER THE ERN GRT LKS LATER TODAY AS UPR SYSTEM AMPLIFIES ABOVE SEASONABLY WARM/MOIST BOUNDARY LYR PRESENT OVER REGION. STRENGTHENING ASCENT MAY YIELD SCATTERED CONVECTION SUFFICIENTLY DEEP TO PRODUCE A FEW LIGHTNING STRIKES THIS AFTN AND EVENING. ISOLATED SMALL HAIL ALSO APPEARS POSSIBLE GIVEN POTENTIAL FOR STEEP LAPSE RATES AND LOW FREEZING LEVELS. ..CORFIDI/TAYLOR.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 16:05:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 11:05:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151606 SWODY1 SPC AC 151604 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1004 AM CST FRI DEC 15 2006 VALID 151630Z - 161200Z ...NO SVR TSTM AREAS FORECAST... INTENSE SYSTEM THAT MOVED ONTO PAC NW COAST LAST NIGHT CURRENTLY MOVING ACROSS SRN PRAIRIE PROVINCES OF SWRN CANADA WITH A STRONG COLD FRONT TRAILING SWWD FROM CENTRAL MT TO NWRN NV. ANOTHER VIGOROUS UPPER TROUGH INITIALLY GREAT LAKES ROTATES EWD ACROSS NERN U.S. BY TONIGHT. BOTH OF THE UPPER SYSTEMS NRN TIER OF CONUS WILL BE ACCOMPANIED BY ONLY MARGINAL INSTABILITY. OTHER THAN ISOLATED LIGHTNING STRIKES ACROSS NERN U.S. WITH UPPER TROUGH AND POSSIBLY NEAR FRONTAL BAND MT TO NV...THE ONLY AREA ATTM THAT THERE APPEARS A CHANCE OF MORE THAN A FEW STRIKES WILL BE THE AREA OF COASTAL OR/WA WHERE A CONTINUED BUT WEAKENING ONSHORE FLOW OF MOIST/MARGINALLY UNSTABLE COLD AIR WILL PERSIST THRU THE PERIOD AHEAD OF AMPLIFYING UPPER TROUGH ALONG THE WEST COAST. VERY MOIST AIR REMAINS S FL...HOWEVER INSTABILITY AND SHEAR HAS WEAKENED PAST 24 HOURS. A FEW THUNDERSTORMS ARE LIKELY THIS AFTERNOON/EVENING...WHERE SOME HEATING CAN OCCUR THRU THE EXTENSIVE MID/UPPER LEVEL CLOUDINESS. ..HALES.. 12/15/2006  From swody1 at goshenarc.org Fri Dec 15 19:41:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 14:41:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151942 SWODY1 SPC AC 151939 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0139 PM CST FRI DEC 15 2006 VALID 152000Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...S FL AND THE KEYS... MESOANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATE ONE LOW LEVEL BOUNDARY ALONG THE FL STRAITS AND A SECONDARY WEAKER CONFLUENCE ZONE FROM NEAR PBI SWWD TOWARD EYW. DESPITE A MOIST LOW-LEVEL AIR MASS...CONSIDERABLE CLOUDS AND WEAK LAPSE RATES HAVE LIMITED DESTABILIZATION WITH MLCAPES AOB 500 J/KG. STILL SOME THREAT OF ISOLATED TSTMS WILL EXIST THIS AFTERNOON AND TONIGHT OWING TO PERSISTENT LOW-LEVEL CONVERGENCE ALONG THESE BOUNDARIES...AND PERHAPS INCREASED LARGER-SCALE FORCING ASSOCIATED WITH WEAK IMPULSE EVIDENT IN WATER VAPOR IMAGERY OVER WRN CUBA. ...HUDSON VALLEY INTO WRN NEW ENGLAND... RADAR AND LIGHTNING DATA INDICATE THAT CONVECTION HAS RECENTLY DEEPENED SUFFICIENTLY TO SUPPORT TSTM DEVELOPMENT. AIR MASS REMAINS DRY...HOWEVER DAYTIME HEATING HAS CONTRIBUTED TO THE DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND RESULTANT WEAK CONDITIONAL INSTABILITY. EXPECT ONGOING CONVECTION TO PERSIST AHEAD OF COLD FRONT INTO WRN NEW ENGLAND THIS EVENING...DRIVEN BY THE MARGINAL INSTABILITY AND STRONG FORCING AHEAD OF MIGRATORY SHORT WAVE TROUGH. ACTIVITY SHOULD TEND TO DISSIPATE LATER THIS EVENING AS LOW-LEVEL LAPSE RATES WEAKEN. ...PACFIC NW COAST... NEXT STRONG SYSTEM NEAR 42N/134W IS FORECAST TO DIG SEWD ACROSS THE ERN PACIFIC TONIGHT WITH LOW-LEVEL ONSHORE FLOW WEAKENING IN RESPONSE TO APPROACH OF ATTENDANT SURFACE CYCLONE. BOTH RUC OBJECTIVE FIELDS AND VISIBLE SATELLITE IMAGERY SUGGEST THAT LAPSE RATES ARE QUITE STEEP...THOUGH LARGE-SCALE FORCING FOR ASCENT WILL REMAIN MARGINAL. SOME POTENTIAL FOR A FEW LIGHTNING STRIKES WILL EXIST THIS AFTERNOON INTO EVENING...HOWEVER THIS THREAT APPEARS TOO MARGINAL TO WARRANT A GENERAL THUNDER AREA. ...NRN ROCKIES INTO GREAT BASIN... SOME POTENTIAL WILL EXIST FOR A FEW LIGHTNING STRIKES WITHIN POST FRONTAL AIR MASS OWING LARGELY TO STRONG MID-LEVEL COOLING AND RESULTANT STEEPENING LAPSE RATES. THIS THREAT IS EXPECTED TO REMAIN QUITE LIMITED AND NO THUNDER AREA WILL BE INCLUDED. ..MEAD.. 12/15/2006  From swody1 at goshenarc.org Sat Dec 16 00:54:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 15 Dec 2006 19:54:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160055 SWODY1 SPC AC 160053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 PM CST FRI DEC 15 2006 VALID 160100Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...FL... MOISTURE REMAINS QUITE HIGH ACROSS SOUTH FL WHERE ILL-DEFINED MID LEVEL DISTURBANCES OF SUBTROPICAL ORIGIN HAVE BEEN PROMOTING AREAS OF CONVECTION FOR THE PAST FEW DAYS. ANOTHER AREA OF SHOWERS AND EMBEDDED TSTMS APPEARS TO BE INCREASING THIS EVENING FROM THE DRY TORTUGAS TO THE FL STRAITS. GIVEN THIS LATEST TREND...AND RECENT GUIDANCE ALSO INDICATING A CONTINUING CHANCE FOR CONVECTIVE QPF ACROSS THE SRN TIP OF FL...A SMALL TSTM AREA WILL BE MAINTAINED. ..CARBIN.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 05:18:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 00:18:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160519 SWODY1 SPC AC 160516 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 PM CST FRI DEC 15 2006 VALID 161200Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVE-TILT LARGE SCALE TROUGH WILL BECOME FIRMLY ESTABLISHED ACROSS THE WRN CONUS THIS PERIOD AS BROAD UPPER RIDGE DEVELOPS ACROSS MUCH OF THE REST NATION EAST OF THE ROCKIES. IMPULSE ASSOCIATED WITH INTENSE THURSDAY/FRIDAY STORM ACROSS THE PACIFIC NORTHWEST WILL CONTINUE TO BREAK AWAY FROM THE LARGER SCALE WRN TROUGH...WITH STRONGEST HEIGHT FALLS SPREADING ACROSS ONTARIO AND WRN QUEBEC. MEANWHILE...ANOTHER POTENT PACIFIC PERTURBATION... CURRENTLY EVIDENT ON WATER VAPOR SATELLITE IMAGERY NEAR 35N 131W...WILL CROSS THE CA COAST THIS MORNING BEFORE MOVING TOWARD THE GREAT BASIN THROUGH TONIGHT. THIS IMPULSE IS FORECAST TO INDUCE CYCLOGENESIS ALONG A DEEP-LAYER BAROCLINIC ZONE SITUATED FROM THE INTERMOUNTAIN WEST TO THE LOWER CO RIVER VALLEY THROUGH EARLY SUNDAY. DESPITE LARGE SCALE HEIGHT RISES FORECAST ACROSS THE NRN GULF AND SRN U.S....A COMPACT SRN STREAM VORT MAX /MOVING EWD ACROSS THE CNTRL GULF OF MEXICO ATTM/ SHOULD PASS OVER SWRN FL THROUGH LATE TODAY. THIS FEATURE MAY ENHANCE DEEP-LAYER ASCENT ALONG A WEAK BAROCLINIC ZONE SITUATED ACROSS THE FL STRAITS. ...NV/UT... A COUPLE OF TSTMS APPEAR POSSIBLE OVER PARTS OF SRN/ERN NV...AND PERHAPS WRN UT...THROUGH THIS EVENING AS LOW STATIC STABILITY ACCOMPANYING UPPER TROUGH ACTS TO ENHANCE LIFT/OROGRAPHIC FORCING NEAR DEEP-LAYER FRONT. MODEST LAPSE RATES AND MOISTENING NEAR THE FRONT SHOULD PROVE ADEQUATE FOR VERY MARGINAL INSTABILITY...BUT PERHAPS ENOUGH TO PROMOTE SPORADIC CG LIGHTNING GIVEN EXPECTED DYNAMICS. ...FL... A MOIST AND WEAKLY UNSTABLE AIR MASS SHOULD REMAIN ALONG A NEARLY STALLED BOUNDARY ACROSS S FL/FL STRAITS. LOW-LEVEL CONVERGENCE MAY STRENGTHEN ALONG THE BOUNDARY WITH APPROACH OF SRN STREAM IMPULSE AND RESULT IN ISOLATED TO SCATTERED TSTMS. WEAK LAPSE RATES AND SHEAR WILL PRECLUDE ANY SEVERE THREAT. ..CARBIN.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 12:19:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 07:19:58 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161220 SWODY1 SPC AC 161218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0618 AM CST SAT DEC 16 2006 VALID 161300Z - 171200Z ...NO SVR TSTM AREAS FORECAST... COLD TROUGH WILL BE DEVELOPING INTO WRN U.S TODAY WITH MUCH OF ERN U.S. UNDER A SLOWLY BUILDING FLAT RIDGE. THE SUBTROPICAL STREAM ACROSS THE GOM AND SRN FL FORECASTED TO SLOWLY WEAKEN AS ONE LAST PERTURBATION TRAVERSES FL PENINSULA TODAY. ANY THUNDERSTORMS THIS FORECAST PERIOD WILL BE CONFINED TO FAR S FL WHERE A VERY MOIST AND WEAKLY UNSTABLE ENVIRONMENT EXISTS. SUFFICIENT LIFT ACROSS STATIONARY SFC BOUNDARY JUST S OF KEYS TO MAINTAIN A LOW THREAT OF EMBEDDED THUNDERSTORMS THRU THE AFTERNOON. ONLY OTHER AREA WHERE A FEW STRIKES COULD OCCUR...MOSTLY TONIGHT... WOULD BE SRN PLATEAU UNDER DEVELOPING COLD TROUGH. THREAT APPEARS TO BE TOO LIMITED TO SUPPORT A 10% COVERAGE. ..HALES.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 15:53:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 10:53:37 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161554 SWODY1 SPC AC 161551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0951 AM CST SAT DEC 16 2006 VALID 161630Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...CA COAST LATE THIS AFTERNOON INTO TONIGHT... WATER VAPOR AND IR IMAGERY SHOW A STRONG MID LEVEL TROUGH APPROACHING 35 N AND 125 W...AND THIS SYSTEM WILL MOVE INLAND OVER CENTRAL/SRN CA TONIGHT. COLD MID LEVEL TEMPERATURES AND STEEP LAPSE RATES ACCOMPANY THE MID LEVEL THERMAL TROUGH...AS EVIDENCED BY THE SWATH OF LOW-TOPPED CONVECTION W OF THE PRIMARY BAROCLINIC BAND JUST OFF THE CA COAST. THOUGH OCEANIC LIGHTNING DATA HAS SHOWN A PRONOUNCED DECREASE IN STRIKES SINCE 10Z...THERE WILL BE SOME THREAT FOR ADDITIONAL CONVECTION ALONG THE IMMEDIATE COAST AS THE TROUGH MOVES INLAND BY TONIGHT. ...S FL THROUGH TONIGHT... A LOW-LATITUDE SHORTWAVE TROUGH IS MOVING EWD FROM THE CENTRAL GULF OF MEXICO TOWARD FL. IN ADVANCE OF THIS TROUGH...A WEAK SURFACE FRONTAL WAVE ACROSS THE SE GULF AND FL STRAITS WILL PROVIDE A FOCUS FOR SOME DEEP CONVECTION THIS PERIOD GIVEN THE MOIST PROFILES AND WEAK INSTABILITY NOTED IN THE 12Z MIAMI AND KEY WEST SOUNDINGS. ..THOMPSON.. 12/16/2006  From swody1 at goshenarc.org Sat Dec 16 19:30:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 14:30:31 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161931 SWODY1 SPC AC 161929 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0129 PM CST SAT DEC 16 2006 VALID 162000Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...CA COAST... STRONG MID-LEVEL TROUGH CONTINUES TO DIG SEWD TOWARD THE CNTR/SRN CA COAST WITH VISIBLE SATELLITE AND RUC OBJECTIVE FIELDS INDICATING A BROAD REGION OF OCEANIC CELLULAR CONVECTION WITHIN AN ENVIRONMENT OF STEEP LOW TO MID-LEVEL LAPSE RATES. THIS TROUGH IS FORECAST TO MOVE ONTO THE SRN CA COAST TONIGHT WITH STEEP LAPSE RATES MOVING INLAND. IT APPEARS THAT THE GREATEST THREAT OF TSTMS WILL EXIST ALONG THE IMMEDIATE COAST...THOUGH THE POTENTIAL FOR ISOLATED THUNDER WILL EXIST AS FAR E AS THE LOWER CO VALLEY. ...S FL AND THE KEYS... A MOIST LOW-LEVEL AIR MASS EXISTS ACROSS THE REGION THIS AFTERNOON...THOUGH CONSIDERABLE CLOUDINESS HAS LIMITED DESTABILIZATION. TSTMS CONTINUE TO INCREASE UPSTREAM FROM WRN CUBA NWD IN ASSOCIATION WITH LOW LATITUDE IMPULSE TRANSLATING THROUGH THE CNTRL/ERN GULF BASIN. EXPECT THAT THE THREAT OF ISOLATED/SCATTERED TSTMS WILL INCREASE OVERNIGHT AS THIS SYSTEM APPROACHES THE PENINSULA. OTHER STORMS WILL LIKELY PERSIST THROUGH THE AFTERNOON ALONG WEAK BOUNDARY NEAR AND E OF VRB. ..MEAD.. 12/16/2006  From swody1 at goshenarc.org Sun Dec 17 00:26:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 16 Dec 2006 19:26:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170027 SWODY1 SPC AC 170025 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0625 PM CST SAT DEC 16 2006 VALID 170100Z - 171200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH WILL CONTINUE MOVING SLOWLY ACROSS THE WRN QUARTER OF THE CONUS...WHILE BROAD ZONE OF WSWLY FLOW PERSISTS ACROSS MOST OF THE REMAINDER OF THE CONUS. THOUGH A FEW SPORADIC LIGHTNING STRIKES MAY OCCUR NEAR/OFF THE W COAST...AND/OR INVOF THE CENTRAL/SRN FL COASTS...OVERALL LIGHTNING COVERAGE SHOULD REMAIN LOW ENOUGH THROUGH THE END OF THE PERIOD TO PRECLUDE ANY ISSUANCE OF THUNDER LINES. ..GOSS.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 05:12:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 00:12:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170513 SWODY1 SPC AC 170511 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 PM CST SAT DEC 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SPLIT FLOW REGIME ALOFT WILL CONTINUE TO EVOLVE ACROSS THE WRN CONUS. SEVERAL SHORT-WAVE TROUGHS WILL TRAVERSE THE U.S./CANADA BORDER IN THE NRN STREAM...WHILE THE SRN STREAM TROUGH OVER THE WRN CONUS REMAINS QUASI-STATIONARY AND TRENDS TOWARD THE DEVELOPMENT OF A CLOSED LOW OVER SRN CA. MEANWHILE...A WEAK UPPER DISTURBANCE INVOF FL/THE BAHAMAS WILL PERSIST WITHIN LARGER-SCALE RIDGE. THIS DISTURBANCE MAY BE ASSOCIATED WITH A FEW ONSHORE LIGHTNING STRIKES OVER S FL AND THE KEYS -- MAINLY DURING THE FIRST HALF OF THE PERIOD. ELSEWHERE...ASIDE FROM A FEW STRAY STRIKES OVER THE WEST IN CONJUNCTION WITH THE WRN UPPER TROUGH...DEEP/MOIST CONVECTION IS NOT ANTICIPATED. ..GOSS.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 12:31:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 07:31:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171232 SWODY1 SPC AC 171229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0629 AM CST SUN DEC 17 2006 VALID 171300Z - 181200Z ...NO SVR TSTM AREAS FORECAST... UPR RIDGING MOVING INTO PAC NW SUPPORTS THE SPLITTING OF WRN TROUGH. NRN PORTION OF TROUGH SHEARS ENEWD FROM ROCKIES INTO PLAINS WHILE CLOSED LOW DEVELOPS INTO SRN CA BY 12Z MON. WITH VERY LIMITED INSTABILITY ANY CONVECTION ASSOCIATED WITH TROUGH OVER THE W SHOULD BE SHALLOW WITH ONLY ISOLATED LIGHTNING STRIKES EXPECTED. TAIL END OF WEAK TROUGH IN SRN BRANCH WILL MAINTAIN THREAT OF SOME CONVECTION EMBEDDED IN THE VERY MOIST AIR MASS ACROSS SRN FL. ANY LIGHTNING SHOULD END BY EVENING AS UPPER SYSTEM MOVES OFF TO THE SE. ..HALES.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 16:29:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 11:29:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171629 SWODY1 SPC AC 171627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST SUN DEC 17 2006 VALID 171630Z - 181200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SCALE FLOW REGIME OVER THE CONUS WILL CHANGE LITTLE THIS PERIOD AS A MID LEVEL TROUGH OVER NV/CA EVOLVES GRADUALLY INTO A CLOSED LOW WITH LITTLE EWD MOVEMENT. A SERIES OF NRN STREAM WAVES WILL MOVE EWD ALONG THE U.S./CANADIAN BORDER...WITH SURFACE RIDGING/COLD FRONT EXPECTED TO SAG SWD ACROSS THE SRN PLAINS IN RESPONSE TO MID LEVEL CONFLUENT FLOW OVER THE NRN PLAINS. LOW-LEVEL MOISTURE /BOUNDARY LAYER DEWPOINTS IN THE 60S/ HAS SPREAD NWD ACROSS E TX INTO SE OK AND AR...BUT POOR LAPSE RATES AND RATHER WARM MID LEVEL TEMPERATURES WILL LIMIT ANY POTENTIAL FOR DEEP CONVECTION ALONG THE FRONTAL ZONE NEAR I-44. OTHERWISE...A SRN STREAM WAVE IS BEGINNING TO MOVE E OF THE FL PENINSULA...AND THE THREAT FOR ANY ADDITIONAL THUNDERSTORMS SHOULD REMAIN GENERALLY S/SE OF THE SE FL COAST AND KEYS. ..THOMPSON.. 12/17/2006  From swody1 at goshenarc.org Sun Dec 17 19:41:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 14:41:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171942 SWODY1 SPC AC 171940 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST SUN DEC 17 2006 VALID 172000Z - 181200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS AND DISCUSSION... EVOLVING UPPER LOW OVER THE GREAT BASIN WILL CONTINUE SEWD INTO THE LOWER CO VALLEY TONIGHT...WHILE WAVE TRAIN REMAINS MORE PROGRESSIVE ACROSS CANADA. IN THE LOW-LEVELS...SURFACE HIGH WILL BUILD SEWD FROM THE NRN HIGH PLAINS INTO CNTRL PLAINS WITH COLD FRONT SLOWLY PUSHING SWD THROUGH THE MID MS VALLEY AND SRN PLAINS. A MOIST LOW-LEVEL AIR MASS EXISTS TODAY TO THE S OF COLD FRONT FROM CNTRL/ERN TX INTO THE OZARK PLATEAU. HOWEVER...12Z RAOBS INDICATE THE PRESENCE OF WARM MID-LEVEL TEMPERATURES AND RESULTANT WEAK LAPSE RATES. SOME SHOWER ACTIVITY WILL BE POSSIBLE OVERNIGHT AS SWLY LLJ REINTENSIFIES AND ENHANCES ISENTROPIC ASCENT NEAR AND N OF SURFACE FRONT FROM OK INTO MO/IL. THIS CONVECTION IS EXPECTED TO REMAIN TOO SHALLOW/WARM TO SUPPORT CHARGE SEPARATION. ELSEWHERE...LOW-LEVEL AIR MASS REMAINS MOIST ACROSS S FL...HOWEVER LARGE-SCALE SUBSIDENCE IN WAKE OF SHORT WAVE TROUGH PUSHING E OF THE BAHAMAS SHOULD SUPPRESS ANY CONVECTIVE DEVELOPMENT. FINALLY...SOME THREAT OF AN ISOLATED LIGHTNING STRIKE OR TWO WILL EXIST NEAR AND N OF THE FOUR CORNERS REGION AS HEIGHT FALLS AHEAD OF UPPER TROUGH CONTRIBUTE TO STEEPENING LAPSE RATES. THIS THREAT IS TOO MARGINAL TO WARRANT A GENERAL THUNDER AREA. ..MEAD.. 12/17/2006  From swody1 at goshenarc.org Mon Dec 18 00:38:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 17 Dec 2006 19:38:57 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180039 SWODY1 SPC AC 180037 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0637 PM CST SUN DEC 17 2006 VALID 180100Z - 181200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... WATER VAPOR AND IR SATELLITE IMAGERY SHOWS DEVELOPING MID/UPPER LEVEL LOW OVER THE CA/NV REGION AS GEOPOTENTIAL HEIGHTS RISE OVER THE PACIFIC NORTHWEST. DOMINANT SWLY FLOW ALOFT EXTENDS FROM NRN BAJA REGION INTO THE GREAT LAKES OVER QUASISTATIONARY FRONT THAT EXTENDS FROM NRN VERMONT THROUGH SWRN MO/NERN OK INTO THE SRN HIGH PLAINS OF TX. SURFACE RIDGING OVER THE CAROLINAS EXTENDS WSWWD THROUGH THE WRN GULF INHIBITING LOW LEVEL MOISTURE RETURN. MODELS HINT AT INCREASING SWLY LOW LEVEL JET OVERNIGHT FROM ERN OK INTO SERN MO WHICH MAY ENHANCE ISOLATED SHALLOW CONVECTION/ISENTROPIC LIFT...BUT POOR LAPSE RATES WOULD INDICATE THE LOW POTENTIAL FOR ISOLATED LIGHTNING ACTIVITY. LATEST RAOB DATA SHOWS THAT 500 MB TEMPS NEAR MID LEVEL LOW CIRCULATION OVER CENTRAL CA ARE AROUND -28C. SHORT RANGE ENSEMBLE FORECASTS INDICATE THAT LIFTED INDICES OFF THE CENTRAL CA COAST MAY BE AROUND -2...THUS ISOLATED LIGHTNING ACTIVITY COULD OCCUR BUT THREAT REMAINS TOO MARGINAL THROUGH THE REMAINDER OF THE PERIOD TO WARRANT A GENERAL THUNDER AREA. ..MCCARTHY.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 05:42:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 00:42:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180543 SWODY1 SPC AC 180541 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST SUN DEC 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... CLOSED UPPER LOW IS FORECAST TO DEVELOP/DRIFT EWD ACROSS THE SWRN U.S. WITH TIME...WITH DOWNSTREAM RIDGE FORECAST OVER THE SERN HALF OF THE CONUS. MEANWHILE...MORE PROGRESSIVE FLOW REGIME IS EXPECTED ACROSS CANADA AND THE NRN U.S. WITHIN FASTER NRN BRANCH OF THE WLYS. AT THE SURFACE...MAIN FEATURE WILL BE AN ENE-WSW BAROCLINIC ZONE INITIALLY EXTENDING FROM SRN NEW ENGLAND WSWWD TO W TX. THIS FEATURE WILL CONTINUE MOVING SSEWD WITH TIME AS 1035 MB HIGH DRIFTS SLOWLY SWD ACROSS THE CONUS. THOUGH MOST OF THE COUNTRY WILL REMAIN STABLE WITH RESPECT TO DEEP MOIST CONVECTION...ISOLATED THUNDERSTORMS ARE FORECAST FROM THE FOUR CORNERS INTO W TX IN ASSOCIATION WITH THE EVOLVING UPPER CLOSED LOW. ...PARTS OF AZ AND UT EWD INTO WRN TX... AS UPPER LOW INTENSIFIES ACROSS THE SWRN STATES...STEEPENING MID-LEVEL LAPSE RATES SHOULD RESULT IN SUFFICIENT INSTABILITY FOR SHOWERS AND ISOLATED THUNDERSTORMS -- PARTICULARLY DURING THE SECOND HALF OF THE PERIOD. OVERNIGHT...LOW-LEVEL JET IS FORECAST TO DEVELOP ACROSS W TX AND INTO ERN NM IN RESPONSE TO SLOW EWD MOVEMENT OF THE UPPER FEATURE. RESULTING LOW-LEVEL WARM/MOIST ADVECTION MAY ALLOW A FEW THUNDERSTORMS TO DEVELOP AS FAR E AS THE TX PANHANDLE/S PLAINS/TRANSPECOS REGION THROUGH 19/12Z. ..GOSS.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 12:50:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 07:50:54 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181251 SWODY1 SPC AC 181249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0649 AM CST MON DEC 18 2006 VALID 181300Z - 191200Z ...NO SVR TSTM AREAS FORECAST... MORNING WATER VAPOR LOOPS AND MODEL GUIDANCE INDICATE LARGE POSITIVELY TILTED UPPER TROUGH FROM THE GREAT BASIN INTO SOUTHERN CA. THE PRIMARY VORT MAX OF THIS TROUGH WILL ROTATE EASTWARD TODAY/TONIGHT INTO THE DESERT SOUTHWEST. LARGE SCALE FORCING FOR ASCENT WILL INCREASE FROM PARTS OF UT/AZ EASTWARD INTO WEST TX MAINLY AFTER 00Z...RESULTING IN AN EXPANDING AREA OF SHOWERY PRECIPITATION. FORECAST SOUNDINGS SHOW ONLY WEAK CAPE VALUES /AOB 250 J/KG/ AND MARGINAL LAPSE RATES. THIS WILL LIMIT LIGHTNING POTENTIAL TO THE MOST ORGANIZED/VIGOROUS DEEP CONVECTION. POTENTIAL FOR SEVERE STORMS APPEARS LOW. ..HART.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 16:04:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 11:04:38 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181605 SWODY1 SPC AC 181603 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1003 AM CST MON DEC 18 2006 VALID 181630Z - 191200Z ...NO SVR TSTM AREAS FORECAST... PART OF A BROAD POSITIVE TILT UPPER TROUGH OVER THE WESTERN THIRD OF THE COUNTRY...WATER VAPOR IMAGERY AND 12Z UPPER AIR DIAGNOSTICS FEATURE A CLOSED UPPER LOW CENTERED OVER SOUTHERN CA. THIS FEATURE WILL SLOWLY MIGRATE EASTWARD ACROSS THE LOWER CO RIVER VALLEY/SOUTHWEST DESERTS INTO EARLY TUESDAY...WITH LARGE SCALE FORCING FOR ASCENT INCREASING/SPREADING EASTWARD ACROSS THE FOUR CORNERS AREA INTO THE SOUTHERN PLAINS THROUGH THE PERIOD. WEAK CONVECTIVE INSTABILITY AND MARGINAL LAPSE RATES WILL SUPPORT A POTENTIAL FOR ISOLATED LIGHTNING STRIKES ACROSS PORTIONS OF THE FOUR CORNERS INTO SOUTHWEST/FAR WEST TX...MAINLY LATE THIS AFTERNOON/TONIGHT. FARTHER EAST...PRESENCE OF UPPER RIDGE AND MARGINAL BUOYANCY/SHALLOW NATURE OF THE CONVECTION SHOULD LIMIT CG LIGHTNING POTENTIAL OVER THE REMAINDER OF THE SOUTHERN PLAINS INTO THE ARKLATEX. ..GUYER/THOMPSON.. 12/18/2006  From swody1 at goshenarc.org Mon Dec 18 20:01:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 15:01:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 182002 SWODY1 SPC AC 182000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0200 PM CST MON DEC 18 2006 VALID 182000Z - 191200Z ...NO SVR TSTM AREAS FORECAST... COLD UPPER LOW THIS AFTERNOON LOCATED VICINITY CA/BAJA CA BORDER IS EXPECTED TO DRIFT SLOWLY EWD INTO SWRN AZ BY 12Z TUE. LARGE SCALE ASCENT AND ASSOCIATED PRECIPITATION WILL BE ON THE INCREASE ERN AZ INTO NM THRU TONIGHT AS 90KT MID LEVEL JET MAX CROSSING NRN BAJA HEADS TOWARD SWRN NM. AVAILABLE INSTABILITY TO SUPPORT CONVECTION E OF UPPER LOW REMAINS LIMITED...BUT WITH CONTINUED HEATING AND STEEPENING OF MID LEVEL LAPSE RATES A FEW THUNDERSTORMS EXPECTED HIGHER TERRAIN ERN AZ/WRN NM. TONIGHT ADDITIONAL ELEVATED WEAK CONVECTION...ISOLATED LIGHTNING...LIKELY WILL DEVELOP INTO ERN NM AND FAR W TX ABOVE THE SHALLOW COLD DOME WITH APPROACH OF THE UPPER JET AND SOME MID LEVEL COOLING. ..HALES.. 12/18/2006  From swody1 at goshenarc.org Tue Dec 19 00:40:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Dec 2006 19:40:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190041 SWODY1 SPC AC 190039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST MON DEC 18 2006 VALID 190100Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH UPPER LOW NOW CENTERED OVER SRN CA/NRN BAJA CA WILL CONTINUE TO PROVIDE MARGINAL INSTABILITY ACROSS THE FOUR CORNERS REGION. AS A RESULT...SHOWERS AND PERHAPS A FEW SPORADIC/EMBEDDED LIGHTNING STRIKES WILL CONTINUE THROUGH THE END OF THE PERIOD ACROSS PARTS OF THE SWRN CONUS. MEANWHILE...INCREASING WARM/MOIST ADVECTION IS FORECAST ACROSS W TX/ERN NM...AS ELY/SELY LOW-LEVEL JET STRENGTHENS AHEAD OF UPPER LOW. THIS MAY YIELD MARGINAL BUT SUFFICIENT CAPE FOR A FEW LIGHTNING STRIKES WITHIN LARGER AREA OF SHALLOWER CONVECTION. ..GOSS.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 05:55:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 00:55:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190555 SWODY1 SPC AC 190553 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1153 PM CST MON DEC 18 2006 VALID 191200Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MAIN UPPER FEATURE OF INTEREST ACROSS THE CONUS THIS PERIOD WILL BE THE SWRN U.S. CLOSED LOW -- INITIALLY FORECAST TO BE CENTERED OVER SRN CA/WRN AZ/NWRN MEXICO. THE LOW IS FORECAST TO PROGRESS EWD THROUGH THE PERIOD...REACHING ERN NM BY 20/12Z. IN RESPONSE TO THIS FEATURE...AN INVERTED SURFACE TROUGH IS EXPECTED TO EVOLVE ACROSS W TX AND WRN OK THROUGH THE END OF THE PERIOD. ...ERN AZ/THE FOUR CORNERS EWD INTO SRN KS/OK/TX... WIDESPREAD SHOWERS AND SCATTERED TO ISOLATED THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD -- INVOF UPPER COLD POOL OVER THE SWRN U.S. AS WELL AS WITHIN WARM ADVECTION REGIME FURTHER E INTO THE SRN HIGH PLAINS. THIS GENERAL SCENARIO WILL CONTINUE/SHIFT SLOWLY EWD WITH TIME...WITH SHOWERS AND SPORADIC LIGHTNING STRIKES ACROSS THE SRN ROCKIES/SWRN U.S. AND MORE WIDESPREAD THUNDERSTORMS SHIFTING ACROSS TX AND OK THROUGH THE END OF THE PERIOD. DEEP-LAYER WIND FIELD WILL INCREASE ACROSS THE SRN PLAINS DURING THE SECOND HALF OF THE PERIOD...AS 80 KT MID-LEVEL JET SPREADS EWD ATOP STRENGTHENING NOCTURNAL LOW-LEVEL JET. HOWEVER...VERY WEAK LAPSE RATES ARE FORECAST ACROSS THE ENTIRE REGION...WHICH WILL GREATLY LIMIT AVAILABLE INSTABILITY. THEREFORE...ANY SEVERE THREAT APPEARS TO BE MINIMAL ATTM. ..GOSS.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 12:50:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 07:50:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191251 SWODY1 SPC AC 191248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0648 AM CST TUE DEC 19 2006 VALID 191300Z - 201200Z ...NO SVR TSTM AREAS FORECAST... LARGE/DEEP UPPER LOW OVER AZ/CA WILL TRACK SLOWLY EASTWARD TODAY INTO NM. MEANWHILE...FORCING FOR UPWARD VERTICAL MOTION WILL OVERSPREAD MUCH OF THE SOUTHERN PLAINS STATES...HELPING TO CREATE A LARGE PRECIPITATION SHIELD ACROSS THE REGION. CLOUD COVER AND WEAK LAPSE RATES WILL SUPPRESS CAPE VALUES TO BELOW 500 J/KG. THIS MAY BE ENOUGH FOR ISOLATED THUNDERSTORMS THROUGHOUT THE FOUR CORNERS REGION INTO PARTS OF TX/OK/KS. STRONG LINEAR FORCING AND INCREASING WIND FIELDS ALOFT MAY SUPPORT A RISK MORE ORGANIZED THUNDERSTORM ACTIVITY OVER TX LATE TONIGHT. HOWEVER...SEVERE THREAT APPEARS TOO LOW TO WARRANT PROBABILITIES AT THIS TIME. ..HART.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 16:29:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 11:29:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191629 SWODY1 SPC AC 191627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST TUE DEC 19 2006 VALID 191630Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SRN ROCKIES AND SRN PLAINS THROUGH TONIGHT... A LARGE CLOSED LOW OVER WRN AZ WILL MOVE EWD INTO NM BY TONIGHT AS A SPEED MAX ROTATES AROUND THE S/SE SIDE OF THE UPPER LOW /OVER NW MEXICO/...AND UPSTREAM HEIGHTS FALL IN ADVANCE OF A SMALL WAVE NEAR 42 N AND 130 W. ONE PRONOUNCED BELT OF ASCENT COINCIDES WITH THE DEEP BAROCLINIC ZONE OVER WRN NM...WHILE TO THE EAST A BROAD REGION OF ASCENT RELATED TO WAA IS EXPECTED TO PERSIST INTO TONIGHT OVER THE SRN PLAINS. REGIONAL 12Z SOUNDINGS SHOW WEAK BUOYANCY /MUCAPE OF 100-400 J/KG/ IN A SWATH FROM THE MIDDLE RIO GRANDE VALLEY NWD OVER THE TX/NM HIGH PLAINS. THIS INSTABILITY...COMBINED WITH THE WAA TODAY AND DIFFERENTIAL CVA DOWNSTREAM FROM THE MID LEVEL LOW BY TONIGHT...WILL SUPPORT A GRADUAL EWD SPREAD OF /PRIMARILY/ ELEVATED THUNDERSTORMS FROM NM/TX PANHANDLE INTO CENTRAL/NW TX...WRN OK...AND SW KS THROUGH TONIGHT. THE PRESENCE OF RATHER POOR LAPSE RATES AND WIDESPREAD CLOUDS WITHIN THE WARM SECTOR ACROSS S CENTRAL TX WILL TEND TO LIMIT ADDITIONAL DESTABILIZATION AND ANY ASSOCIATED SEVERE STORM THREAT THROUGH TONIGHT. ..THOMPSON.. 12/19/2006  From swody1 at goshenarc.org Tue Dec 19 19:49:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 14:49:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191949 SWODY1 SPC AC 191947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CST TUE DEC 19 2006 VALID 192000Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SRN ROCKIES INTO THE SRN PLAINS... BROAD AREA OF NON-SEVERE THUNDERSTORMS WILL CONTINUE TO EXPAND ACROSS THE REGION AHEAD OF SLOW MOVING UPPER LOW NOW MOVING ACROSS AZ. LEADING AREA OF ELEVATED THUNDERSTORMS OVER THE SRN HIGH PLAINS ATTM APPEARS ASSOCIATED WITH BROAD LOW LEVEL WAA WITHIN MID LEVEL MOISTURE PLUME WELL AHEAD OF APPROACHING SYSTEM. THIS ACTIVITY WILL LIKELY EXPAND NNEWD THIS EVENING...WITH ANOTHER BATCH OF MOIST CONVECTION AND THUNDERSTORMS DEVELOPING NEARER THE MID/UPPER LEVEL SYSTEM WHICH WILL LIKEWISE SHIFT ENEWD OVERNIGHT. FORECAST SOUNDINGS CONTINUE TO INDICATE MARGINAL INSTABILITY WITH ELEVATED PARCELS...SUGGESTING EMBEDDED THUNDERSTORMS WILL PERSIST. ..EVANS.. 12/19/2006  From swody1 at goshenarc.org Wed Dec 20 00:30:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Dec 2006 19:30:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200031 SWODY1 SPC AC 200029 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0629 PM CST TUE DEC 19 2006 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW NOW CENTERED OVER AZ WILL CONTINUE MOVING EWD INTO NM THROUGH THE END OF THE PERIOD. WIDESPREAD PRECIPITATION WITH EMBEDDED THUNDERSTORMS WILL PERSIST...FROM THE UPPER LOW CENTER EWD INTO THE CENTRAL AND SRN PLAINS. THOUGH MINIMAL INSTABILITY WILL PRECLUDE ANY APPRECIABLE SEVERE THREAT...EXPECT AN INCREASE IN THUNDERSTORM COVERAGE FROM SERN NM EWD ACROSS TX/OK AS LOW-LEVEL JET AND ASSOCIATED WARM ADVECTION INCREASE OVERNIGHT. ELSEWHERE...LACK OF INSTABILITY ACROSS THE REMAINDER OF THE CONUS IS FORECAST TO HINDER ANY POTENTIAL FOR DEEP MOIST CONVECTION. ..GOSS.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 05:48:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 00:48:47 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200549 SWODY1 SPC AC 200547 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1147 PM CST TUE DEC 19 2006 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THOUGH A MID-LEVEL SHORT-WAVE TROUGH IN THE NRN STREAM WILL AFFECT THE PAC NW AND A SECOND WILL CROSS THE GREAT LAKES/NEW ENGLAND...MAIN FEATURE WITH RESPECT TO DEEP MOIST CONVECTION WILL BE THE UPPER LOW MOVING INTO THE CENTRAL CONUS. THIS FEATURE...INITIALLY FORECAST OVER NM...IS EXPECTED TO MOVE ENEWD TO SWRN KS/THE TX AND OK PANHANDLES BY 21/12Z. AT THE SURFACE...LOW PRESSURE CENTER IS FORECAST TO LINGER OVER THE WRN KS/WRN OK REGION...WHILE TRAILING FRONT SHIFTS EWD ACROSS TX/OK THROUGH THE DAY...AND INTO THE LOWER MS VALLEY REGION BY THE END OF THE PERIOD. ...SERN TX INTO LA... SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOULD BE ONGOING ACROSS THIS REGION AT THE START OF THE PERIOD...WITHIN WEAK WARM ADVECTION REGIME. THOUGH BOUNDARY-LAYER AIRMASS WILL MOISTEN INTO LA AS SURFACE FLOW VEERS WITH TIME AHEAD OF APPROACHING SURFACE BOUNDARY...WEAK LAPSE RATES WILL CONTINUE TO LIMIT THE POTENTIAL FOR DESTABILIZATION. ADDITIONALLY...STRONGER DEEP-LAYER WIND FIELD IS FORECAST TO REMAIN NW OF THE WRN GULF COAST REGION...WITH MID-LEVEL JET CORE FORECAST TO REMAIN ACROSS N TX/OK THROUGH THE PERIOD. NONETHELESS...STORMS SHOULD BECOME MORE NUMEROUS THROUGH THE SECOND HALF OF THE PERIOD AS SURFACE BOUNDARY APPROACHES. LIMITED INSTABILITY/WEAK LAPSE RATES WILL LIMIT UPDRAFT INTENSITY...AND SO LITTLE HAIL POTENTIAL AND ONLY A MARGINAL WIND THREAT IS INDICATED. ALSO...WITH DEWPOINTS FORECAST IN THE MID 60S ACROSS SERN TX AND INTO MUCH OF LA AND MODERATE SHEAR EXPECTED IN THE 0-1 KM LAYER...AN ISOLATED TORNADO CANNOT BE RULED OUT. HOWEVER...OVERALL SEVERE POTENTIAL SHOULD REMAIN LOW/BELOW SLIGHT RISK THRESHOLDS THROUGH THE PERIOD. ..GOSS.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 12:35:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 07:35:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201235 SWODY1 SPC AC 201233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 AM CST WED DEC 20 2006 VALID 201300Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER MS VALLEY... MORNING SATELLITE LOOPS SHOW A DEEP UPPER LOW OVER NM. THIS SYSTEM WILL MOVE NORTHEASTWARD INTO PARTS OF WESTERN KS AND THE OK PANHANDLE BY EVENING. BAND OF 90-110 KNOT MID LEVEL WINDS WILL PUNCH EASTWARD ACROSS TX...WITH PRIMARY SURFACE COLD FRONT ALSO SURGING EASTWARD INTO EAST TX BY 21/00Z. STRONG SOUTHERLY LOW LEVEL WINDS AHEAD OF FRONT WILL TRANSPORT GULF MOISTURE NORTHWARD INTO EAST TX AND MUCH OF AR/LA/MS WITH DEWPOINTS RISING INTO THE MID 60S ACROSS THIS AREA OVERNIGHT. FORECAST SOUNDINGS SHOW WEAK LAPSE RATES AND ONLY MARGINAL CAPE VALUES. NEVERTHELESS...LARGE SCALE FORCING FOR ASCENT AND AMPLE LOW/MID LEVEL MOISTURE WILL AID IN THE DEVELOPMENT OF WIDESPREAD SHOWERS AND OCCASIONAL THUNDERSTORMS. STRENGTH OF WIND FIELDS SUGGEST A POTENTIAL OF ISOLATED THUNDERSTORM INTENSIFICATION AND A MARGINAL SEVERE THREAT. DAMAGING WINDS OR PERHAPS A TORNADO APPEAR TO BE THE MAIN CONCERNS. ...WESTERN WA... COLD TEMPERATURES ALOFT ASSOCIATED WITH THE NEXT UPPER TROUGH APPROACHING THE PACIFIC NORTHWEST COAST WILL LIKELY RESULT IN ISOLATED LIGHTNING STRIKES LATE TONIGHT OFF THE WA COAST. PRESENT INDICATIONS ARE THAT THREAT WILL NOT MOVE INLAND UNTIL THURSDAY. ..HART.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 16:31:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 11:31:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201632 SWODY1 SPC AC 201630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1030 AM CST WED DEC 20 2006 VALID 201630Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... DEEP MID LEVEL CLOSED LOW OVER NE NM THIS MORNING WILL MOVE SLOWLY ENEWD OVER THE SRN PLAINS THROUGH EARLY THURSDAY. AT THE SURFACE...AN OCCLUDED LOW INVOF NE NM WILL GRADUALLY FILL OVER THE OK PANHANDLE BY THIS EVENING...WHILE A SURFACE COLD FRONT MOVES EWD ACROSS ERN OK/TX. REGIONAL SOUNDINGS SHOW SOME WEAK ELEVATED INSTABILITY AS FAR N AS KS...AS WELL AS RATHER MARGINAL SURFACE-BASED INSTABILITY IN THE WARM SECTOR FARTHER S FROM SE OK INTO SE TX. VERTICAL SHEAR AND FORCING FOR ASCENT WILL REMAIN STRONGER FROM E TX NWD...WHILE THE SOMEWHAT STRONGER INSTABILITY WILL BE CONFINED MORE TO SE TX AND SRN LA BY TONIGHT. GIVEN THE POOR PHASING BETWEEN THE UNSTABLE WARM SECTOR AND THE FORCING/VERTICAL SHEAR...ANY SEVERE STORM THREAT WILL REMAIN RATHER MARGINAL ACROSS SE TX AND SRN LA THROUGH TONIGHT. OTHERWISE...A SHORTWAVE TROUGH NEAR 44 N AND 136 W WILL APPROACH NW WA BY EARLY THURSDAY. OCEANIC LIGHTNING DATA SHOW A FEW STRIKES WITH THIS SYSTEM...BUT ANY THUNDERSTORM THREAT SHOULD REMAIN OFFSHORE THIS FORECAST PERIOD. ..THOMPSON.. 12/20/2006  From swody1 at goshenarc.org Wed Dec 20 19:44:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 14:44:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201945 SWODY1 SPC AC 201942 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0142 PM CST WED DEC 20 2006 VALID 202000Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...E TX TO LOWER MS VALLEY... COLD FRONT WILL CONTINUE TO SPREAD EWD THIS AFTERNOON THROUGH ERN OK/TX TOWARD THE MS VALLEY...AND SHOULD EXTEND FROM THE MID MS VALLEY SWWD THROUGH LA TO OFF THE TX GULF COAST BY 12Z THURSDAY...AS ASSOCIATED UPPER LOW MOVES SLOWLY TOWARD THE CENTRAL/SRN PLAINS. DESPITE MOISTURE ADVECTION INTO THE LOWER MS VALLEY THIS FORECAST PERIOD...WEAK LAPSE RATES ARE EXPECTED TO MAINTAIN MARGINAL INSTABILITY...AT BEST...FOR TSTM DEVELOPMENT ALONG AND AHEAD OF THE COLD FRONT. ALTHOUGH INSTABILITY IS GREATER SWD ALONG THE TX COASTAL PLAIN...THE LACK OF STRONGER LARGE SCALE FORCING SHOULD CONTINUE TO LIMIT THE POTENTIAL FOR DEEP CONVECTION IN THAT REGION. A WEAK SRN STREAM IMPULSE MOVING NEWD ACROSS THE LOWER MS VALLEY AT THIS TIME IS LIKELY AIDING IN THE RECENT INCREASE IN TSTM ACTIVITY JUST OFF THE LA COAST. THIS ACTIVITY IS LOCATED GENERALLY ALONG AND NORTH OF A SURFACE BOUNDARY WHICH EXTENDED FROM THE UPPER TX COAST EWD INTO THE FAR NRN GULF OF MEXICO. SHORT TERM MODELS SUGGEST THE WRN EXTENT OF THIS BOUNDARY MAY MOVE INLAND ACROSS FAR SE TX AND SW LA...THUS INCREASING THE POTENTIAL FOR SURFACE BASED STORMS LATER TONIGHT. EFFECTIVE BULK SHEAR AND LOW LEVEL SHEAR VALUES WILL BE SUFFICIENT FOR ROTATING TSTMS WITH AN ISOLATED TORNADO THREAT. HOWEVER...WITH ONLY WEAK INSTABILITY AND THE LACK OF STRONGER FORCING ALOFT LATER IN THE FORECAST PERIOD...WILL MAINTAIN LOW SEVERE PROBABILITIES WITH THIS OUTLOOK. ...WRN WA... PACIFIC TROUGH...CURRENTLY LOCATED NEAR 44 N 134 W...WILL APPROACH NW WA AND BRITISH COLUMBIA LATE IN THE FORECAST PERIOD. COLD MID LEVEL TEMPERATURES WITH THIS SYSTEM AND INCREASING ASCENT SHOULD MAINTAIN AREA OF TSTMS WITH TROUGH...BUT ANY TSTM THREAT SHOULD REMAIN OFFSHORE THROUGH 12Z THURSDAY. ..PETERS.. 12/20/2006  From swody1 at goshenarc.org Thu Dec 21 00:36:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Dec 2006 19:36:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210036 SWODY1 SPC AC 210034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST WED DEC 20 2006 VALID 210100Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER/MID MS VALLEY... NEAR SURFACE BASED CONVECTION WILL REMAIN CONFINED TO EXTREME SERN TX AND SRN LA TONIGHT AS MARINE LAYER STRUGGLES TO MOVE VERY FAR INLAND. EVEN SO...PARCEL BUOYANCY WILL PROVE SOMEWHAT LIMITED AS LAPSE RATES ARE MARGINAL AND MOIST. 00Z SOUNDING FROM LCH SUGGESTS CONVECTION IS ROOTED NEAR 950 MB...WHILE MARGINAL LOW LEVEL SHEAR AT SRN EXTENT OF WARM CONVEYOR SEEMS LESS THAN IDEAL FOR MEANINGFUL ORGANIZED SEVERE STORMS. AT THIS TIME IT APPEARS DEEP LAYER SHEAR IS ADEQUATE FOR DEEP ROTATION...BUT OVERALL SEVERE THREAT SHOULD REMAIN QUITE ISOLATED...HENCE LOW PROBABILITIES FOR GUSTY WINDS OR PERHAPS A BRIEF WEAK TORNADO. FARTHER NORTH...WIDESPREAD ELEVATED CONVECTION WITHIN ZONE OF STRONGER FORCING SHOULD CONTINUE THE REST OF THE PERIOD FROM AR INTO MO. THIS ACTIVITY IS LARGELY DRIVEN BY STRONG ASCENT ACTING ON WEAK INSTABILITY WITHIN 700-400MB LAYER. ..DARROW.. 12/21/2006  From swody1 at goshenarc.org Sun Dec 31 16:12:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 31 Dec 2006 11:12:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311616 SWODY1 SPC AC 311614 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1014 AM CST SUN DEC 31 2006 VALID 311630Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SOUTHEAST STATES AND TN VALLEY... SATELLITE IMAGERY SHOWS DEEP UPPER LOW OVER KS/MO LIFTING NORTHEASTWARD INTO THE MIDWEST. BAND OF 90-110 KNOT SOUTHWESTERLY MID LEVEL WINDS WILL ROTATE ACROSS THE LOWER/MID MS VALLEY TODAY...WHILE 40-60 KNOT SOUTHERLY LOW LEVEL JET WILL EXTEND ACROSS THE GULF COAST STATES AND TN VALLEY. RESULTING VERTICAL SHEAR PROFILE WOULD BE VERY FAVORABLE FOR ORGANIZED/ROTATION STORMS IF SUFFICIENT INSTABILITY WERE PRESENT. HOWEVER...SURFACE DEWPOINTS ARE BELOW 60F FROM NORTHERN AL NORTHWARD WHICH SHOULD LIMIT AFTERNOON MLCAPE VALUES TO BELOW 300 J/KG AND PRECLUDE AN ORGANIZED SEVERE THREAT. HIGHER DEWPOINTS VALUES /IN THE MID 60S/ LIE ACROSS PARTS OF AL/FL/GA...WHERE MLCAPE VALUES MAY APPROACH 500 J/KG THIS AFTERNOON. HOWEVER...FORECAST SOUNDINGS SHOW WEAK LOW/MID LEVEL LAPSE RATES AND VEERING LOW LEVEL WINDS WITH TIME. EMBEDDED STORMS IN THIS AREA WILL BE CAPABLE OF GUSTY WINDS OR A BRIEF TORNADO. HOWEVER...OVERALL SEVERE THREAT APPEARS QUITE LIMITED TODAY. ...MID/UPPER MS VALLEY... DRY SLOT IS NOTED ON WATER VAPOR IMAGERY ROTATING AROUND UPPER LOW INTO THE MID MS VALLEY. CLOUDS ARE ERODING IN THIS AREA...WHICH SHOULD RESULT IN A FEW HOURS OF DAYTIME HEATING THIS AFTERNOON ACROSS PARTS OF NORTHERN IL/IND. STEEPENING LAPSE RATES BENEATH MID LEVEL COLD POOL...COMBINED WITH RESIDUAL LOW LEVEL MOISTURE...IS EXPECTED TO PROVIDE AFTERNOON MLCAPE VALUES AROUND 500 J/KG. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE FORECAST IN THIS AREA...LIFTING NORTHWARD INTO PARTS OF WI/MI DURING THE EVENING. THERMODYNAMIC PROFILES ARE QUITE COLD...SUGGESTING THE POTENTIAL FOR SMALL HAIL IN STRONGER CELLS. ..HART.. 12/31/2006  From swody1 at goshenarc.org Sun Dec 31 19:47:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 31 Dec 2006 14:47:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311951 SWODY1 SPC AC 311949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SUN DEC 31 2006 VALID 312000Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SE GA AND NRN FL... AT THE SFC...A COLD FRONT IS LOCATED FROM MIDDLE TN EXTENDING SWD ACROSS CNTRL AL. A LINE OF THUNDERSTORMS EXISTS WELL AHEAD OF THE BOUNDARY IN SW GA AND ACROSS THE ERN FL PANHANDLE. SFC DEWPOINTS AHEAD OF THE LINE RANGE FROM THE MID 60S F TO THE LOWER 70S F AND OBJECTIVE ANALYSIS SHOWS AN AXIS OF WEAK INSTABILITY PRESENT ACROSS THE NRN PENINSULA OF FL INTO SRN AND ERN GA. THE LINE SHOULD REMAIN SOMEWHAT ORGANIZED MOVING EWD INTO THE INSTABILITY AXIS LATE THIS AFTERNOON. IN ADDITION...OBJECTIVE ANALYSIS CURRENTLY SHOWS A SMALL 50 KT MID-LEVEL JET LOCATED BEHIND THE LINE WHICH IS POSSIBLY ASSOCIATED WITH A SUBTLE SHORTWAVE TROUGH. AS THIS FEATURE DRIFTS EWD THIS AFTERNOON...SHEAR PROFILES ALONG THE LINE MAY BE JUST STRONG ENOUGH FOR MARGINALLY SEVERE THUNDERSTORMS CAPABLE OF ISOLATED WIND DAMAGE. ...ERN IL/IND/SW LOWER MI... LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL LOW LIFTING NEWD ACROSS MO TOWARD THE LOWER OH VALLEY. VERY STRONG LARGE-SCALE ASCENT EXISTS IN A BROAD ZONE AHEAD OF THE UPPER-LOW. THIS ALONG WITH STEEP LAPSE RATES WILL PROMOTE THE DEVELOPMENT OF SCATTERED THUNDERSTORMS LATE THIS AFTERNOON FROM THE CHICAGO IL AREA EXTENDING SEWD TO THE VICINITY OF INDIANAPOLIS IN. THE STRONGLY SHEARED ENVIRONMENT ALONG WITH COLD TEMPS ALOFT ASSOCIATED WITH THE UPPER-LOW COULD RESULT IN A FEW STORMS CAPABLE OF PRODUCING HAIL MAINLY NEAR OR JUST AFTER PEAK HEATING. ..BROYLES.. 12/31/2006