SPC AC 101927
STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.
VALID 102000Z - 111200Z
THERE IS A HIGH RISK OF SVR TSTMS THROUGH TONIGHT OVER A LARGE PART
OF KENTUCKY...TENNESSEE...NORTHERN ALABAMA...AND MUCH OF
MISSISSIPPI. THE MDT RISK AREA IS TO THE RIGHT OF A LINE FROM
35 W LUL 25 NE HEZ 45 S GLH 35 SSW PAH 25 SW EVV 15 WNW LEX 35 WNW
JKL 25 S LOZ 30 W RMG 35 W LUL.
SURROUNDING THE HIGH RISK AREA...THERE IS A MDT RISK OF SVR TSTMS
IN NORTHEASTERN LOUISIANA...EASTERN ARKANSAS...SOUTHEASTERN
MISSOURI...SOUTHERN ILLINOIS...SOUTHERN INDIANA...EASTERN TENNESSEE
...CENTRAL MISSISSIPPI...SOUTHERN MISSISSIPPI...AND NORTHWEST
GEORGIA. THE MDT RISK AREA IS TO THE RIGHT OF A LINE FROM 40 W ATL
15 ENE SEM 35 NNE MSY 25 NNW LFT 40 NNW ESF CGI 25 ENE MTO 35 NNE
HUF 10 NE IND 30 WNW HTS 20 NNW 5I3 40 W ATL.
SURROUNDING THE MDT RISK AREA...THERE IS A SLGT RISK OF SVR TSTMS
TO THE RIGHT OF A LINE FROM 30 SW BUF BFD 25 SE AOO 30 W DAN 15 NW
ABY 30 SSE CEW ...CONT... 40 SSE LCH 20 N POE 15 ENE CGX 30 N GRR
70 SE OSC.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SE BPT 45 S SHV
40 WSW ELD 60 SW ARG MMO 15 NE JVL 25 N VOK 25 SSE IWD 40 NE CMX
...CONT... 15 NE MSS GFL 20 NNE EEN 20 N HUL ...CONT... DAB 15 WNW
PIE.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 NNE BLI 35 SSE
SEA 40 ESE DLS 35 W BKE 15 N 27U 30 E COD 30 ENE CPR 30 SE LBL 20
NW CDS 25 SSE TCC 35 ENE GUP 60 SE LMT 25 N ACV.
LATEST SURFACE ANALYSIS SHOWS A STRONG AREA OF LOW PRESSURE
CENTERED OVER NORTHWESTERN PARTS OF ONTARIO...WITH A COLD FRONT
TRAILING SOUTHWARD ACROSS WESTERN LOWER MICHIGAN...INTO SOUTH-
EASTERN MISSOURI AND NORTHEAST TEXAS. WATER VAPOR IMAGERY
INDICATES A LARGE SCALE UPPER TROUGH IS AMPLIFYING ACROSS THE
NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY. MEANWHILE...SEVERAL
SHORTWAVE MAXIMA CONTINUE TO MOVE ONSHORE ACROSS THE WESTERN U.S.
...LOWER OHIO/TENNESSEE/MIDDLE AND LOWER MISSISSIPPI VALLEYS...
WIDESPREAD SEVERE THUNDERSTORM EVENT CONTINUES TO UNFOLD ACROSS
PARTS OF THE GREAT LAKES INTO THE LOWER MISSISSIPPI VALLEY.
INCREASING SOUTHERLY LOW LEVEL FLOW IS MAINTAINING THE TRANSPORT OF
GULF MOISTURE NORTHWARD AHEAD OF THE APPROACHING FRONT. VISIBLE
IMAGERY SHOWS AN EXTENSIVE FIELD OF CUMULUS FROM LOUISIANA
NORTHWARD INTO WESTERN TENNESSEE AND KENTUCKY. THE AIR MASS IN THE
WARM SECTOR IS BECOMING MODERATELY TO VERY UNSTABLE. OBJECTIVELY
ANALYZED DATA SUGGEST SURFACE BASED CAPES ARE IN THE 2000 TO 3000
J/KG RANGE. SPECIAL 18Z SOUNDINGS IN THE HIGH RISK AREA SHOW THE
PRESENCE OF A CAP...BUT IT DOES NOT APPEAR TO BE PARTICULARLY
STRONG. ADDITIONAL AFTERNOON HEATING COMBINED WITH FORCING WITH
THE APPROACHING UPPER TROUGH AND FRONT SHOULD BREAK THE CAP OVER
THE NEXT FEW HOURS...AND THUNDERSTORMS WILL DEVELOP.
VAD WIND PROFILES ACROSS THE HIGH AND MODERATE RISK AREAS SHOW
STRONG LOW TO MID LEVEL FLOW...WITH UP TO 60 TO 65 KNOTS OF DEEP
LAYER SHEAR. FLOW HAS LARGELY BEEN UNIDIRECTIONAL...OR NEARLY SO
...BUT SOME LOW LEVEL BACKING WILL LIKELY OCCUR AHEAD OF THE FRONT
AND THIS WILL CREATE AN INCREASINGLY FAVORABLE ENVIRONMENT FOR
SEVERE THUNDERSTORMS...INCLUDING SUPERCELLS AND TORNADOES.
THUNDERSTORMS HAVE ALREADY DEVELOPED FROM LOWER MICHIGAN TO
SOUTHEASTERN MISSOURI. THE ACTIVITY HAS EVOLVED INTO A LINE...AND
SOME OF THE STRONGER STORMS HAVE ALREADY PRODUCED SEVERE WIND AND
HAIL. THERE WILL LIKELY BE ADDITIONAL DEVELOPMENT ALONG THE FRONT
THROUGHOUT THE NIGHT AS THE STRONG FORCING BREAKS THE CAP.
WIDESPREAD DAMAGING WINDS...SOME LIKELY PRODUCING SIGNIFICANT
DAMAGE OR SPEEDS...AS WELL AS HAIL ARE POSSIBLE WITH THESE STORMS.
ISOLATED STORMS AHEAD OF THE LINE WILL HAVE THE POTENTIAL TO
PRODUCE TORNADOES...AND SOME COULD BE STRONG. AS THE NIGHT
PROGRESSES...THE ACTIVITY SHOULD EVOLVE INTO A SQUALL LINE AS THE
STORMS MOVE RAPIDLY EASTWARD/NORTHEASTWARD OVERNIGHT.
..REHBEIN.. 11/10/02
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 0100Z