Severe Thunderstorm Warning 121, NWS Green Bay, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
315 AM CDT THU AUG 1 2002

MAIN CHALLENGE WITH THE FCST IS TIMING/COVERAGE OF TSTA TDY AND SEVERE
POTENTIAL.

BAND OF STG/SVR CONVECTION OVER FAR NW WI...MOVING MAINLY EAST ON EDGE
OF H7 12 CAPPING EDGE. H8/3 THICKNESS FIELDS SUPPORT CONVECTION TO
CONTINUE TO MOVE EAST...BUT SOME SLIGHT SRN DRIFT/BLDG NOTED ON DLH 88D
RADAR.  FAR NC WI WILL BE CLOSE TO THIS CONVECTION FOR POSSIBLE WARNINGS
EARLY THIS AM.  CONVECTION ASSOC WITH A S/W AHEAD OF THE FRONT.

OTHERWISE AVN MODEL HAS HANDLED THIS PATTERN THE BEST THE LAST FEW
DAYS...WITH ABOUT A 6 HR SLOWER MOVEMENT WITH THE PCPN AND FRONTAL
POSITION THIS AM COMPARED TO 24 HOURS AGO RUNS.  IR SAT IMAGE INDICATES
CONVECTION LINGERING BACK WEST TO THE DKTS AT 08Z DUE TO INCREASING WLY
FLOW ALOFT.  FRONT PROGGED TO MOVE INTO NW WI THIS AM AND EXPECTED TO
EXIT THE SE PORTION OF THE CWA AT 00Z.  DUE TO THE SLOWER MOVEMENT OF
THE FRONT...EXPECT MAINLY AFTN TIMING OVER EC WI AND POSSIBLY A FEW
HOURS INTO THE EARLY EVENING.

BESIDES THE BOWING FEATURE ACRS THE FAR NORTHWEST...INSTABILITY WILL
BECOME GREATER AHEAD OF THE FRONT OVER ROUGHLY THE SE HALF OF THE CWA...
DUE TO THE LATER TIMING INTO THE AFTN.  MID LEVEL CAP WEAKENS AND CIN
DECREASES AS FRONT APPROACHES.

A COOLER AIRMASS WILL THEN INVADE THE REGION LATER TONIGHT AND INTO
FRIDAY. NO OTHER CHANGES TO LATER PDS AT THIS TIME.

.GRB...NONE.

HELMAN
WWW.CRH.NOAA.GOV/GRB

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-312030-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREEN BAY WI
1200 PM CDT WED JUL 31 2002

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

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
TONIGHT OVER MUCH OF CENTRAL AND NORTHERN WISCONSIN. THERE IS ALSO A
SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST AND EAST CENTRAL
WISCONSIN ON THURSDAY.

CURRENT SHOWER AND NON-SEVERE THUNDERSTORM ACTIVITY AND ITS ASSOCIATED
CLOUD COVER MAY LIMIT THE INSTABILITY OVER THE FORECAST AREA FOR A WHILE
THIS AFTERNOON. HOWEVER...A VERY UNSTABLE AIR MASS WILL CONTINUE TO
DEVELOP NEAR A WARM FRONT IN SOUTHERN MINNESOTA AND WEST CENTRAL
WISCONSIN. SEVERE THUNDERSTORMS ARE FORECAST TO DEVELOP NEAR THIS
BOUNDARY BY MID-AFTERNOON...THEN TRACK EAST INTO PARTS OF CENTRAL AND
NORTH CENTRAL WISCONSIN BY LATE AFTERNOON OR EARLY EVENING. THE STORMS
WILL BE CAPABLE OF PRODUCING DAMAGING WINDS...LARGE HAIL AND ISOLATED
TORNADOES...AND MAY AFFECT SOME OF THE SAME AREAS THAT WERE HIT HARD
LAST NIGHT. ALTHOUGH INSTABILITY WILL NOT BE AS GREAT ACROSS FAR
NORTHERN WISCONSIN...WIND SHEAR WILL BE STRONGER...SO THE SEVERE THREAT
IS STILL SIGNIFICANT.

A COLD FRONT WILL APPROACH THE FORECAST AREA LATE TONIGHT...AND SHIFT
THROUGH NORTHEAST AND EAST CENTRAL WISCONSIN AROUND MIDDAY. THIS FRONT
COULD TRIGGER ANOTHER ROUND OF SEVERE WEATHER ACROSS THE SOUTHEAST HALF
OF THE FORECAST AREA TOMORROW.

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON...TONIGHT AND ON
THURSDAY.

KIECKBUSCH
WWW.CRH.NOAA.GOV/GRB