[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 180519
SWODY1
SPC AC 180517

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1217 AM CDT SUN JUL 18 2004

VALID 181200Z - 191200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 NE
MQT 45 NNW GRB 25 ENE LSE 35 SSE RWF 25 NW ABR 60 N ISN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 WSW FHU 60 NE PHX
45 NNE LAS 55 S BIH 45 NNE FAT 30 NE RBL 50 ESE CEC 35 SSE OTH 30 E
BLI ...CONT... 50 W ANJ 30 ESE VOK 30 SE GRI 20 NNE EAR 25 NW REJ 30
NNW 4BQ 20 SW SHR 40 SSE CPR 30 SSE GLD 10 NW DDC 25 WSW CSM 10 WNW
BWD 10 ENE CLL 20 N POE 20 SSW JAN 45 SW 0A8 15 NNW BHM 45 SSE MKL
25 SW PAH 20 NNW MTO 30 NNE BEH 40 SE OSC.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 SW P07 30 WSW CNM
15 SSE TCS 30 WSW SVC 40 ESE DUG.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN
PLAINS INTO THE WRN GREAT LAKES...

...SYNOPSIS...
LITTLE CHANGE IS FORECAST IN THE LARGE-SCALE PATTERN THROUGH THE
PERIOD WITH DOMINANT FEATURES BEING DEEP TROUGH IN THE E AND
AMPLIFIED RIDGE ACROSS THE ROCKIES. MORE SPECIFICALLY...SHORTWAVE
TROUGH AND ASSOCIATED UPPER-LEVEL JET STREAK WILL LIFT NEWD FROM
MEAN TROUGH POSITION ACROSS MIDDLE ATLANTIC STATES/DELMARVA REGION
TODAY. FARTHER NW...SHORTWAVE TROUGH / CURRENTLY AMPLIFYING OVER
CNTRL SASKATCHEWAN/MANITOBA / WILL TRANSLATE SEWD ACROSS ONTARIO AND
THE UPPER MS VALLEY/WRN GREAT LAKES...WHILE NEXT UPSTREAM SYSTEM
PROGRESSES NEWD ONTO THE PACIFIC NW COAST.

AT THE SURFACE...PRIMARY LOW ASSOCIATED WITH MIDDLE ATLANTIC
SHORTWAVE TROUGH WILL DEVELOP NEWD FROM SC INTO THE CHESAPEAKE BAY
REGION BY EARLY EVENING WITH TRAILING BAROCLINIC ZONE BEING
REINFORCED ACROSS THE CAROLINA PIEDMONT SWWD INTO THE CNTRL GULF
COAST. MEANWHILE...COLD FRONT OVER CNTRL CANADA WILL PROGRESS
SEWD...LIKELY EXTENDING FROM A SURFACE LOW OVER NWRN ONTARIO SWWD
ACROSS N-CNTRL MN/CNTRL ND AND INTO THE NRN ROCKIES BY EARLY
EVENING.

...NRN PLAINS INTO THE WRN GREAT LAKES...
LARGE MCS HAS EVOLVED TONIGHT AHEAD OF SHORTWAVE TROUGH OVER CNTRL
PARTS OF SASKATCHEWAN/MANITOBA. THIS CONVECTION WILL LIKELY CONTINUE
TO MOVE/DEVELOP SEWD OVERNIGHT...POSSIBLY REACHING THE ND OR MN
BORDER EARLY IN THE FORECAST PERIOD. RATHER STEEP LOW TO MID-LEVEL
LAPSE RATES COUPLED WITH DEWPOINTS GENERALLY IN THE 60S SHOULD ALLOW
DOWNSTREAM AIRMASS ACROSS THE DAKOTAS INTO MN TO BECOME MODERATELY
UNSTABLE WITH MLCAPES APPROACHING 1500-2000 J/KG.

GREATEST POTENTIAL FOR SEVERE WEATHER APPEARS TO BE ASSOCIATED WITH
ANY MCS THAT MOVES SEWD OUT OF S-CNTRL CANADA DURING THE DAY AND/OR
WITH ANY TSTMS THAT DEVELOP ALONG APPROACHING COLD FRONT. FORECAST
SOUNDINGS WITHIN PRE-FRONTAL AIRMASS INDICATE STRONGLY VEERING WIND
PROFILES WITH 35-45KTS OF DEEP-LAYER SHEAR AND 150-250 M2/S2 0-3KM
SRH...SUGGESTING THE LIKLIHOOD OF SUPERCELLS IN ADDITION TO BOWING
STRUCTURES. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE PRIMARY
SEVERE WEATHER THREATS. POTENTIAL FOR ISOLATED TORNADOES WILL ALSO
EXIST...ESPECIALLY LATE THIS AFTERNOON INTO EVENING ACROSS NRN INTO
CNTRL MN WHERE BEST COMBINATION OF LOW-LEVEL HUMIDITY AND SHEAR IS
EXPECTED TO CO-EXIST.

DAMAGING WIND THREAT COULD SPREAD AS FAR E AS WRN UP OF MI INTO
NRN/CNTRL WI OVERNIGHT IN ASSOCIATION WITH FORWARD-PROPAGATING MCS
WHICH SHOULD BE MAINTAINED AHEAD OF AMPLIFYING SHORTWAVE TROUGH.

...SRN NEW ENGLAND SWD ACROSS THE DELMARVA REGION INTO CNTRL/ERN
CAROLINAS...
STRONG...DYNAMIC FORCING FOR ASCENT AHEAD OF SHORTWAVE TROUGH AND
WITHIN EXIT REGION OF UPPER JET STREAK WILL SPREAD NWD FROM THE
DELMARVA TOWARD SRN NEW ENGLAND TODAY WITH SCATTERED TO NUMEROUS
TSTMS LIKELY FOCUSED ALONG AND N OF RETREATING WARM FRONT. LATEST
MODEL GUIDANCE SUGGESTS THAT PRIMARY FACTOR LIMITING SEVERE TSTM
DEVELOPMENT WILL BE WEAK INSTABILITY OWING TO THE ANTICIPATED
WIDESPREAD CLOUDS/PRECIPITATION.

FARTHER S...IT APPEARS THAT TSTMS MAY DEVELOP LATER TODAY ALONG COLD
FRONT WITHIN DRY SLOT REGION OF SHORTWAVE TROUGH LIFTING NEWD
THROUGH THE AREA. DIABATIC HEATING COUPLED WITH STEEPER MID-LEVEL
LAPSE RATES ON CYCLONIC SIDE OF UPPER-LEVEL JET SHOULD CONTRIBUTE TO
MLCAPES OF 500-1000 J/KG. COMBINATION OF HIGH-LEVEL FLOW OF 80-90KTS
WITH 30-40KTS IN THE MID-LEVELS SHOULD BE SUPPORTIVE OF ORGANIZED
TSTMS CAPABLE OF ISOLATED DAMAGING WINDS AND LARGE HAIL.

IF IT BECOMES APPARENT THAT MORE INSTABILITY WILL DEVELOP THAN IS
CURRENTLY ANTICIPATED...PORTIONS OF DISCUSSION AREA MAY NEED TO BE
UPGRADED TO SLIGHT RISK.

...NRN ROCKIES...
RATHER STEEP LOW TO MID-LEVEL LAPSE RATES AND BOUNDARY-LAYER
DEWPOINTS IN THE 50S SHOULD CONTRIBUTE TO AIRMASS DESTABILIZATION
THROUGH THE DAY WITH MLCAPES INCREASING TO 500 J/KG. APPROACH OF
PACIFIC NW MID-LEVEL TROUGH AND ASSOCIATED FRONTAL SYSTEM...IN
CONJUNCTION WITH LOW-LEVEL UPSLOPE COMPONENT IN
TOPOGRAPHICALLY-FAVORED AREAS SHOULD LEAD TO AN INCREASE IN STORM
COVERAGE AND INTENSITY THROUGH THE AFTERNOON AND EVENING HOURS.
THOUGH IT APPEARS THAT THE STRONGEST SHEAR WILL BE DISPLACED TO THE
W OF THE BEST INSTABILITY...POTENTIAL WILL STILL EXIST FOR A FEW
INTENSE STORMS CAPABLE OF ISOLATED STRONG WIND GUSTS AND MARGINALLY
SEVERE HAIL.

..MEAD/CROSBIE.. 07/18/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.