[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 180547
SWODY1
SPC AC 180542

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1242 AM CDT SAT SEP 18 2004

VALID 181200Z - 191200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 NE HVR 45 NNE BIL
50 ESE WEY 35 S LND 30 NE CAG 20 W ASE 50 NE DRO 40 W TAD 35 NW CAO
40 ENE ROW 60 WNW MRF.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 NW DRT 25 NNW JCT
30 SSW FTW 65 WNW LFK 25 NE HOU GLS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 W CZZ 30 NE RAL 30
N DAG 60 S EKO 30 SSE BYI 60 NE BOI 65 WSW BNO 60 NW UKI.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 N PIE 15 SE DAB.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SE EWN 10 ENE GSB
45 SE LYH 25 WNW BWI 25 SE AVP BOS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NNW ELO 15 SE HIB
35 ESE BJI 55 SW DVL 70 NE MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 NNW EMP 30 W BIE
OFK 15 NW SUX 25 S FRM 25 ESE MSP 55 NE EAU 35 E AUW 30 SW PIA 40
SSW STL 35 WNW UNO 35 S UMN 20 SSW CNU 20 NNW EMP.

...NO SVR TSTM AREAS FORECAST...

LATEST SATELLITE IMAGERY SUPPORTS MODEL PROGS INDICATING
AMPLIFICATION OF UPPER FLOW PATTERN WILL CONTINUE THROUGH THIS
FORECAST PERIOD.  INITIAL SIGNIFICANT SHORT WAVE TROUGH...NOW ALONG
THE PACIFIC NORTHWEST COAST...WILL LIFT ACROSS THE NORTHERN ROCKIES
TODAY...AS ANOTHER STRONG UPPER JET STREAK DIGS OFF THE PACIFIC
COAST. DOWNSTREAM OF SHARPENING LARGE-SCALE TROUGH AXIS ALONG THE
PACIFIC COAST...UPPER RIDGE OVER THE PLAINS IS FORECAST TO BUILD
NORTHWARD/SHIFT SLOWLY EASTWARD...AND EXTEND ALONG AN AXIS FROM THE
RIO GRANDE VALLEY INTO ONTARIO BY SATURDAY NIGHT.  FARTHER
EAST...MEAN TROUGH AXIS ASSOCIATED WITH POLAR/SUBTROPICAL SHORT
WAVES WILL SLOWLY SHIFT INTO THE VICINITY OF THE ATLANTIC COAST.

...MID ATLANTIC COAST STATES...
FRONTAL ZONE ACROSS SOUTHERN NEW ENGLAND INTO THE NORTHERN MID
ATLANTIC COAST AREAS...AND WEAKENING/ELONGATING CIRCULATION
ASSOCIATED WITH REMNANTS OF IVAN...WILL STILL PROVIDE FOCUS FOR
CONVECTIVE DEVELOPMENT TODAY.  BOUNDARY LAYER WILL REMAIN VERY MOIST
WITH DEW POINTS AROUND 70F EAST OF THESE FEATURES...AND SHOULD
BECOME WEAK TO MODERATELY UNSTABLE WITH DAYTIME HEATING.  WITH
STRONGER LOW-LEVEL FLOW FIELDS/SHEAR PROFILES ALREADY SHIFTING
OFFSHORE...WARM THERMODYNAMIC PROFILES WITH WEAK LAPSE RATES ARE
EXPECTED TO PRECLUDE SEVERE THREAT.  FRONTAL ZONE AND SURFACE LOW
ARE PROGGED TO SHIFT OFFSHORE BY LATE AFTERNOON.  AS THIS OCCURS...
CONVECTIVE POTENTIAL WILL DIMINISH.

...MID MISSOURI/UPPER MISSISSIPPI VALLEY AND PLAINS...
CONVECTIVE CLUSTER LIKELY WILL BE ONGOING AT THE START OF THE
FORECAST PERIOD ACROSS PARTS OF NORTHEAST KANSAS/NORTHERN MISSOURI. 
HOWEVER...AS NOCTURNAL LOW-LEVEL JET WEAKENS AND BACKS IN RESPONSE
TO EVOLVING UPSTREAM UPPER FLOW PATTERN...ACTIVITY IS EXPECTED TO
SLOWLY DIMINISH BY THE 15-18Z TIME FRAME.

THEREAFTER...CONVECTIVE POTENTIAL THROUGH THE REMAINDER OF THE
FORECAST PERIOD ACROSS MUCH OF THE CENTRAL U.S. IS UNCERTAIN...
PRIMARILY DUE TO STRENGTHENING INHIBITION BENEATH BUILDING UPPER
RIDGE. ONE FOCUS FOR CONVECTIVE INITIATION COULD BE CONFLUENT BAND
NEAR SOUTHERLY LOW-LEVEL JET AXIS ACROSS EASTERN NEBRASKA.  ETA
POINT FORECAST SOUNDINGS SUGGEST LOW-LEVEL WARM ADVECTION AND STRONG
HEATING MAY BECOME SUFFICIENT TO OVERCOME CAP BY LATE AFTERNOON.  AT
LEAST AN ISOLATED STORM OR TWO APPEARS POSSIBLE...AND...IF THIS
OCCURS...THERMODYNAMIC ENVIRONMENT WILL BE SUPPORTIVE OF SOME
HAIL/ISOLATED DOWNBURSTS.

WHILE LIMITED CONVECTIVE POTENTIAL ACROSS THE MID MISSOURI VALLEY
DIMINISHES WITH LOSS OF HEATING...SCATTERED AREAS OF CONVECTION ALSO
APPEAR POSSIBLE TONIGHT ALONG EASTERN PERIPHERY OF MID-LEVEL CAP
ACROSS PARTS OF THE UPPER MISSISSIPPI VALLEY.  THIS WILL OCCUR AS
STRONG SOUTHERLY LOW-LEVEL JET BEGINS TO VEER...PERHAPS AIDED BY
FORCING ASSOCIATED WITH WEAK HIGH-LEVEL SHORT WAVE...WHICH IS NOW
LIFTING FROM THE GREAT BASIN INTO THE CENTRAL ROCKIES. THIS SYSTEM
IS PROGGED TO CONTINUE INTO CREST OF UPPER RIDGE BY LATE TONIGHT.

FARTHER SOUTH...MOIST AND MUCH MORE WEAKLY CAPPED AIR MASS OVER
CENTRAL/EASTERN TEXAS IS EXPECTED TO BECOME SUPPORTIVE OF A FEW
THUNDERSTORMS DURING THE HOURS NEAR/SHORTLY AFTER PEAK HEATING.

...WESTERN STATES...
INFLUX OF LOWER LATITUDE MID/HIGH-LEVEL MOISTURE IS PROGGED INTO THE
SOUTHERN PLATEAU AND GREAT BASIN...AHEAD OF AMPLIFYING PACIFIC COAST
TROUGH.  THIS WILL BE ACCOMPANIED BY INCREASING THUNDERSTORM
ACTIVITY TODAY.  CONSIDERABLE CLOUD COVER MAY REDUCE SURFACE HEATING
AND LIMIT BROADER SEVERE THREAT.  HOWEVER...ON WESTERN GRADIENT OF
RETURNING MOISTURE...CONVECTIVE DESTABILIZATION MAY PROVE SUFFICIENT
FOR VIGOROUS THUNDERSTORM ACTIVITY.  LOW/MID-LEVEL FLOW FIELDS/SHEAR
PROFILES WILL GRADUALLY STRENGTHEN EASTWARD INTO THIS AREA DURING
THE DAY...CONTRIBUTING TO AT LEAST SOME RISK FOR DAMAGING SURFACE
GUSTS/MARGINAL SEVERE HAIL.

...FLORIDA PENINSULA...
SOUTHEAST OF UPPER TROUGH/SHEAR AXIS ACROSS THE CENTRAL FLORIDA
PENINSULA...THERMODYNAMIC ENVIRONMENT WILL REMAIN SUPPORTIVE OF 
SCATTERED THUNDERSTORM ACTIVITY ALONG SEA BREEZES DURING THE
AFTERNOON AND EARLY EVENING HOURS.

..KERR/JEWELL.. 09/18/2004

...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.