Severe Thunderstorm Warning 126, NWS La Crosse, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
310 PM CDT MON AUG 14 2000

FORECAST CONCERNS FOR THIS PACKAGE INCLUDE CONVECTIVE TRENDS TONIGHT
WITH PASSAGE OF FRONTAL BOUNDARY...AND THEN TEMPERATURES TUESDAY
THROUGH WEDNESDAY.

18Z SURFACE ANALYSIS SHOWS LOW PRESSURE OVER EASTERN SOUTH DAKOTA
WITH TRAILING TROUGH/COLD FRONT EXTENDING SOUTHWARD THROUGH CENTRAL
NEBRASKA. WARM FRONT SOMEWHAT HARD TO DISCERN...BUT EXTENDS ACROSS
CENTRAL MINNESOTA INTO NORTHWEST WISCONSIN. MAIN CLOUD SHIELD
ALONG AND TO THE NORTH OF THE WARM FRONT...WITH CLEAR SKIES ACROSS
SOUTHWEST MINNESOTA. CONVECTION OCCURRING ACROSS NORTHERN MINNESOTA
ON NOSE OF 20 KT TO 30 KT LOW LEVEL JET.

12Z MODELS INITIALIZE WELL...BUT AGAIN SHOW SOME DISCREPANCIES IN
THE QPF FIELDS. ONCE AGAIN APPEARS ETA AND AVN HAVE A BIT BETTER
HANDLE ON THE SMALLER FEATURES.

IN THE SHORT TERM...ATMOSPHERE SOUTH OF WARM FRONT REMAINS CAPPED
THIS AFTERNOON WITH 10C PLUS TEMPERATURES AT 700MB. BEST MOISTURE
CONVERGENCE/UPPER LEVEL DIVERGENCE TO REMAIN ACROSS THE NORTHERN HALF
OF MINNESOTA AND NORTHERN WISCONSIN TONIGHT. SHORTWAVE MOVING THROUGH
SOUTHERN CANADA SHOULD ENHANCE CONVECTIVE ACTIVITY LATER THIS
AFTERNOON AND EVENING. FARTHER SOUTH BETTER CHANCES MAY COME WITH
CONVERGENCE ALONG APPROACHING COLD FRONT. THUS WILL STILL CONTINUE
LOWER POPS FROM ROCHESTER...SOUTHEASTWARD INTO SOUTHWEST WISCONSIN.

FRONTAL SYSTEM SHOULD EXIT THE REGION BY MORNING WITH MUCH DRIER AIR
BEING ADVECTED INTO THE REGION. ETA PROGS SURFACE DEWPOINTS (NOW 65
TO 70) TO DROP INTO THE 50S BY TUESDAY AFTERNOON. BY WEDNESDAY...
SURFACE HIGH MOVES EAST WITH RETURN FLOW RE-ESTABLISHING ITSELF
ACROSS THE WESTERN ZONES. WILL GO WITH A LOW POPS WEST AND DRY
ELSEWHERE.

IN THE EXTENDED...UNSETTLED WEATHER TO CONTINUE THROUGH THURSDAY...
BEFORE RIDGE RE-ESTABLISHES ITSELF ACROSS THE AREA. TEMPERATURES
SHOULD DROP BACK TO NEAR OR SLIGHTLY BELOW NORMALS.

GUIDANCE TEMPERATURES RATHER SIMILAR AND SO NOT TO MUCH DEVIATION.

COORDINATED WITH KMKX...KGRB...KMSP

.LSE...NONE.

RABERDING

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-150100-

HAZARDOUS WEATHER OUTLOOK...RETRANSMIT
NATIONAL WEATHER SERVICE LA CROSSE WI
1247 PM CDT MON AUG 14 2000

...SPOTTER ACTIVATION POSSIBLE THIS EVENING AND OVERNIGHT IN WEST
CENTRAL AND CENTRAL WISCONSIN...

A LARGE COMPLEX OF THUNDERSTORMS OVER NORTHERN MINNESOTA AT MIDDAY...
WILL CONTINUE TO TRACK EAST-SOUTHEASTWARD INTO WISCONSIN BY LATE THIS
AFTERNOON. THESE THUNDERSTORMS WILL CONTINUE TO DEVELOP THROUGHOUT
THE AFTERNOON...AND REACH PORTIONS OF WEST CENTRAL WISCONSIN AFTER
SUNSET. THE MAIN THREAT FROM THESE STORMS WILL BE LARGE HAIL AND
DAMAGING WINDS...ALTHOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT.

ELSEWHERE...ACROSS FAR SOUTHWEST WISCONSIN...SOUTHEAST MINNESOTA...
AND NORTHEAST IOWA...THUNDERSTORM DEVELOPMENT SHOULD REMAIN INHIBITED
BY WARM AIR AT THE MID LEVELS OF THE ATMOSPHERE.

SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING AND OVERNIGHT IN
PORTIONS OF WEST CENTRAL AND CENTRAL WISCONSIN. THE GREATEST
THREAT FOR SEVERE WEATHER WILL BE IN LOCATIONS ROUGHLY ALONG...AND TO
THE NORTH AND EAST OF INTERSTATE 94. SPOTTER GROUPS AND EMERGENCY
MANAGERS IN THESE AREAS SHOULD STAY TUNED FOR FURTHER UPDATES...AND
IF A WATCH IS ISSUED FOR YOUR AREA...ASSUME SPOTTER ACTIVATION WILL
BE NEEDED.

GUYER/DB