[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 171251
SWODY1
SPC AC 171246

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0746 AM CDT FRI SEP 17 2004

VALID 171300Z - 181200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 E
TRI 20 ESE PSK CHO RIC 10 SSW GSB 35 S FLO CAE SPA 35 WNW HKY 40 E
TRI.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 E INL 50 S DLH 30
E RST 10 W IRK 35 WNW SGF 10 W MKO 40 ENE DAL 55 NNE CLL 20 SSE BPT
...CONT... 10 W ELP 40 WNW CVS 40 NNE CAO 45 NNW GLD 50 NE ANW 15 NW
BKX 45 WNW AXN 65 W RRT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 ENE CTB 30 W BTM
25 N BOI 25 SSE CEC.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 S IPL 35 ENE TRM
15 SW EED 30 SSE IGM 55 WSW SOW 30 NE SAD 35 SSW DMN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 WSW PNS 25 NNE CEW
20 ENE MGM 35 NNW BHM 50 WSW BNA 35 SW SDF 25 SSE CAK 35 WSW GFL 15
ESE PWM.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SC/VA/NC...

...SYNOPSIS...
MID/UPPER LEVEL PATTERN THROUGH PERIOD IS EXPECTED TO BE
CHARACTERIZED BY PROGRESSIVE NRN STREAM FROM PACIFIC NW TO NEW
ENGLAND AND CANADIAN MARITIMES...WHILE UPPER RIDGING INTENSIFIES
OVER SRN PLAINS.  HEIGHTS ARE FCST TO FALL OVER WA/ORE AS SHORTWAVE
TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY SW-NE OF VANCOUVER
ISLAND -- SHOULD PIVOT ASHORE THIS EVENING ROUGHLY BETWEEN
18/00Z-06Z.  MEANWHILE...SFC AND UPPER AIR REMAINS OF TC IVAN SHOULD
MOVE NEWD OVER SRN APPALACHIANS REGION.  CENTER OF THIS CYCLONE
SHOULD FINISH LINKING WITH SFC FRONTAL ZONE AND MOVE TO S-CENTRAL VA
OR N-CENTRAL NC BY END OF PERIOD...WITH COLD FRONT SWWD TO WRN FL
PANHANDLE AND NEWD ACROSS SRN/ERN NEW ENGLAND. WRN PORTION OF THIS
FRONT IS RETREATING NWD ACROSS OK AND SW KS AS SUBTLE WARM FRONT. 
SFC ANALYSIS SHOWS THIS FEATURE ALSO IS ACCOMPANIED BY PRONOUNCED
SFC MOIST AXIS...WITH DEW POINTS LOW 60S TO LOW 70S F FROM SWRN KS
SEWD ACROSS CENTRAL OK TO N-CENTRAL TX.

...NC/VA/SC...
VERTICAL SHEAR WILL REMAIN FAVORABLE FOR SUPERCELLS AND RISK OF A
FEW TORNADOES ACROSS MUCH OF REGION...ASSOCIATED WITH REMAINS OF
IVAN.  0-1 KM SRH SHOULD REMAIN IN 150-300 J/KG RANGE...AS
ISALLOBARIC FORCING ENE-ESE OF SFC LOW MAINTAINS SOME BACKING OF
FLOW...HELPING TO ENHANCE SHEAR ESPECIALLY OVER PIEDMONT AREA AND
WRN PORTIONS COASTAL PLAIN.  FARTHER E...VERTICAL SHEAR SHOULD
DECREASE WITH DISTANCE FROM CYCLONE CENTER.  ALSO...KINEMATIC
SUPPORT SHOULD DIMINISH WITH SWD EXTENT OVER GA AND NRN FL AS VEERED
BOUNDARY LAYER FLOW REDUCES LOW LEVEL SHEAR AND CONVERGENCE. 
TORNADO THREAT TENDENCY SHOULD BE STRONGLY DIURNAL TODAY BECAUSE OF
THERMODYNAMIC SUPPORT. BROKEN CLOUD COVER WILL MODULATE DIURNAL
INCREASE IN BUOYANCY ESPECIALLY NRN PORTIONS OUTLOOK AREA. 
HOWEVER...MODIFIED RAOBS AND MODEL FCST SOUNDINGS SUGGEST MLCAPES
1200-1700 J/KG ARE POSSIBLE WITH SFC INSOLATION AND DEW POINTS 70S F
OVERCOMING WEAK DEEP-LAYER LAPSE RATES.  TORNADO POTENTIAL SHOULD
GRADUALLY DIMINISH AGAIN THROUGH EVENING INTO TONIGHT AS RESULT OF
SLOW DIABATIC SFC COOLING AND CONTINUED WEAKENING OF KINEMATIC
FIELDS WITH IVAN CIRCULATION.

...CENTRAL PLAINS...
NRN KS ONGOING/ELEVATED TSTMS SUPPORTED BY STRONG LOW LEVEL WAA
PROFILE AND MARGINAL BUT INCREASING LOW LEVEL MOISTURE -- ABOVE
RELATIVELY STABLE BOUNDARY LAYER.  ELEVATED MUCAPE IN 1000-2000 J/KG
RANGE SUPPORTED BY 8-9 DEG C/KM MIDLEVEL LAPSE RATES WILL SUPPORT
POTENTIAL FOR ISOLATED/MARGINAL SEVERE HAIL ANOTHER COUPLE HOURS
UNTIL LLJ WEAKENS WITH DIMINISHED VERTICAL DECOUPLING OF BOUNDARY
LAYER.

ANOTHER ROUND OF TSTMS IS POSSIBLE THIS AFTERNOON INVOF SFC LOW AND
TROUGH OVER PORTIONS WRN KS...PERHAPS NW OK ALSO...WITH ISOLATED
DAMAGING GUSTS AND LARGE HAIL CONDITIONALLY POSSIBLE.  CONVECTIVE
COVERAGE IN THIS AREA WILL BE LIMITED BY STRONG CAPPING...HOWEVER
HEATING TO NEAR CONVECTIVE TEMPERATURE AND LIFT NEAR TROUGH SHOULD
CONTRIBUTE TO SOME DEVELOPMENT LATE AFTERNOON. EXPECT STEEP LAPSE
RATES ALOFT AND STRONG HEATING/MIXING THIS AFTERNOON...WITH HIGH
CLOUD BASES BENEATH 500-1200 J/KG MLCAPE.  STRONG DIRECTIONAL SHEAR
SHOULD CONTINUE...BUT WITH WEAK TO NEGATIVE 0-6 KM SPEED SHEAR. 
CONVECTION SHOULD DIMINISH QUICKLY AFTER SUNSET AS DIABATIC COOLING
ELIMINATES SBCAPE.

..EDWARDS/BANACOS.. 09/17/2004

...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.