Severe Thunderstorm Warning 58, NWS Green Bay, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
330 PM CDT MON AUG 14 2000

SVR TSTM THREAT IS THE CONCERN FOR TONIGHT.

STORMS CONTINUE TO DEVELOP OVER N MN IN AREA OF FAVORABLE H8 THETA-E
ADVECTION/MOISTURE CONVG ON NOSE OF 30KT JET AND STRONGLY DIFFLUENT
FLOW ALOFT. THE SFC WARM FRONT EXTENDED FROM LOW PRESSURE OVER EASTERN
SD...THROUGH CNTRL MN...THEN SE THROUGH SOUTHERN WI. THE FRONT WAS
STRENGTHENING OVER CNTRL MN/WC WI DUE TO THE AFFECTS OF CLOUDS AND
STORMS TO THE NORTH...AND LAPS SHOWED INTENSE SFC MOISTURE CONVG
DEVELOPING THERE. INSTABILITY WAS ALSO IMPRESSIVE OVER CNTRL MN...
WHERE 19Z GOES DERIVED SOUNDINGS SHOWING CAPES OF 4000-5000 J/KG.
ATMOSPHERE WAS STILL STRONGLY CAPPED THERE...WITH CINH OF 100-200 J/KG.

ETA/AVN AGAIN PREFERRED FOR THIS FCST...WITH NGM LOOKING TOO FAST AND
STILL TRYING TO GENERATE THE GREATEST PRECIP SOUTH OF OUR AREA. MODELS
LIFT SFC FRONT INTO CNTRL WI BY EVG...WHICH IS PROBABLY WHERE IT WILL
STAY UNTIL AFTER THE EVG CONVECTION MOVES THROUGH AND SFC WAVE LIFTS NE.
H8 THETA-E ADV/MOISTURE CONVG IS BULLSEYED ACROSS NORTHERN WI BETWEEN
00Z-06Z...WHICH SEEMS REASONABLE. WILL CONTINUE LIKELY POPS NORTH...
WITH HIGH CHC POPS SOUTH. THE DEGREE OF INSTABILITY...LLVL WIND SHEAR
(HELICITIES 300-400) AND STRENGTH OF MID-LEVEL FLOW...AS WELL AS
FAVORABLE SYNOPTIC SETUP NORTH OF THE WARM FRONT SUGGEST A POSSIBLE
WIDESPREAD DAMAGING WIND EVENT ACROSS GRB CWA. SUPERCELLS WITH ISOLD
TORNADOES AND LARGE HAIL ARE POSSIBLE IN WSTRN CWA EARLY THIS EVG.
INSTABILITY SHOULD BECOME MARGINAL FARTHER EAST...WITH ACTIVITY LIKELY
EVOLVING INTO A LINEAR MCS WITH DAMAGING WINDS THE PRIMARY THREAT...
ESPECIALLY CLOSE TO THE SFC BOUNDARY. COLD FRONT APPROACHES THE CWA
AFT 06Z...WITH CONTINUED THREAT OF STG STORMS ALONG IT LATE TONIGHT.

THE FRONT SHOULD QUICKLY EXIT GRB CWA TUES MORNING...WITH RAPID DRYING
OCCURRING IN ITS WAKE AS POTENT DRY SLOT ROTATES INTO THE C/NE WI.
WARM START TO THE DAY AND ABUNDANT SUNSHINE WILL OFFSET CAA...LEADING
TO ANOTHER WARM...BUT MUCH LESS HUMID DAY.

SFC HIGH TO AFFECT NORTHEAST WI TUES NGT INTO WEDS...WITH NEXT CHC OF
PRECIP ARRIVING WEDS NGT AND CONTINUING INTO THURSDAY.

COORD WITH ARX/MKX...THANKS.

.GRB...NONE.

KIECKBUSCH
WWW.CRH.NOAA.GOV/GRB

WIZ005-010>013-018>022-030-031-035>040-045-048>050-141900-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREEN BAY WI
1200 PM CDT MON AUG 14 2000

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND PARTS OF CENTRAL
AND NORTH-CENTRAL WISCONSIN.

THERE IS A SLIGHT RISK OF SEVERE WEATHER IN NORTH CENTRAL WISCONSIN
LATE THIS AFTERNOON...AND ACROSS THE ENTIRE FORECAST AREA TONIGHT.

A WARM FRONT WILL LIFT INTO CENTRAL WISCONSIN BY EVENING. A SURGE OF
WARM...MOIST AND VERY UNSTABLE AIR OVER THIS BOUNDARY WILL RESULT IN
THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND TONIGHT. ONGOING
SEVERE THUNDERSTORM ACTIVITY IN NORTHERN MINNESOTA WILL LIKELY MOVE
EAST-SOUTHEAST...REACHING NORTH CENTRAL WISCONSIN AFTER 4:00 PM. A
FEW OF THESE STORMS COULD REMAIN SEVERE...WITH DAMAGING WINDS AND
LARGE HAIL. OTHER THUNDERSTORMS COMPLEXES WILL LIKELY MOVE THROUGH
THE REST OF THE FORECAST AREA THIS EVENING AND OVERNIGHT. WITH
SEASONABLY STRONG WINDS ALOFT EXPECTED...THERE IS A THREAT OF
WIDESPREAD WIND DAMAGE WITH THESE STORMS. WIND SHEAR WILL ALSO BE
VERY STRONG...SUGGESTING A POTENTIAL FOR TORNADOES. THE GREATEST THREAT
OF TORNADOES EXISTS OVER PORTIONS OF NORTH CENTRAL AND CENTRAL WISCONSIN
EARLY THIS EVENING...WHEN THE BEST COMBINATION OF INSTABILITY AND WIND
SHEAR IS EXPECTED.

SPOTTER ACTIVATION WILL LIKELY BE NEEDED LATE THIS AFTERNOON AND
TONIGHT.

ADDITIONAL INFORMATION CAN BE FOUND IN THE SHORT-TERM FORECAST ONCE
THUNDERSTORMS DEVELOP OR MOVE TOWARDS THE FORECAST AREA.

KIECKBUSCH
WWW.CRH.NOAA.GOV/GRB