330  
FXUS63 KGRB 021142  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
642 AM CDT WED SEP 2 2026  
 
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE  
   
KEY MESSAGES  
 
- SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 6 AM FOR PORTAGE,  
WAUPACA, WAUSHARA, WINNEBAGO AND WOOD COUNTIES.  
 
- ROUND OF THUNDERSTORMS EXPECTED THIS MORNING, ESPECIALLY ACROSS  
CENTRAL AND EAST-CENTRAL WI. SOME OF THE STRONGER STORMS MAY  
PRODUCE DAMAGING WINDS AND UP TO 1" HAIL.  
 
- ANOTHER ROUND OF THUNDERSTORMS ARE POSSIBLE AGAIN LATE WEDNESDAY  
NIGHT AND THURSDAY. THIS COMPLEX OF THUNDERSTORMS COULD BECOME  
STRONG OR SEVERE. THERE IS A MARGINAL (LEVEL 1) OR SLIGHT (LEVEL  
2) RISK OF SEVERE STORMS SOUTH OF A MERRILL TO MANITOWOC LINE.  
 
- ABOVE NORMAL TEMPERATURES AND PERIODIC RAIN/STORM CHANCES WILL  
CONTINUE INTO THE WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 229 AM CDT WED SEP 2 2026  
 
SCATTERED THUNDERSTORMS DEVELOPED ACROSS WINNEBAGO, CALUMET AND  
MANITOWOC COUNTIES EARLY THIS MORNING IN RESPONSE TO 850MB  
WARM ADVECTION. SOME OF THE STRONGER STORMS COULD PRODUCE SMALL  
HAIL, ESPECIALLY ACROSS WAUSHARA COUNTY THROUGH 3 AM. MEANWHILE,  
ADDITIONAL CONVECTION WAS NOTED ACROSS WEST-CENTRAL WI WITH  
COMPLEX OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST MINNESOTA WHERE  
A GUST TO 59 KNOTS WAS RECORDED. THIS COMPLEX OF STORMS IS  
EXPECTED TO MOVE INTO CENTRAL WI BY 5 AM. SOME OF THE STORMS COULD  
PRODUCE STRONG/DAMAGING WINDS AND HAIL UP TO ONE INCH IN DIAMETER.  
 
THE SHOWERS AND STORMS COME TO AN END LATER THIS MORNING WITH DRY  
CONDITIONS EXPECTED THIS AFTERNOON. A BREAK IN THE STORMS IS  
EXPECTED WEDNESDAY EVENING, WITH THE NEXT ROUND OF STORMS EXPECTED  
LATE WEDNESDAY NIGHT AND THURSDAY. TIMING AND LOCATION HARD TO  
PINPOINT BETWEEN THE DIFFERING MODEL SOLUTIONS. THE LATEST NAM  
HAS TRENDED SOUTHWARD WHICH SEEMS REASONABLE WITH THE BEST  
INSTABILITY TO OUR SOUTH. THE STORM PREDICTION CENTER DAY 2  
SEVERE STORM OUTLOOK HAS A MARGINAL (LEVEL 1 OF 5) OR SLIGHT  
(LEVEL 2 OF 5) SOUTH OF A MERILL TO MANITOWOC LINE. FROM FRIDAY  
THROUGH THE WEEKEND, THERE ARE PERIODIC CHANCES OF THUNDERSTORMS  
WHILE ABOVE NORMAL TEMPERATURES CONTINUE INTO NEXT WEEK.  
 
 
   
AVIATION  
FOR 12Z TAF ISSUANCE  
ISSUED AT 636 AM CDT WED SEP 2 2026  
 
SCATTERED SHOWERS AND THUNDERSTORMS WILL EXIT NORTHEAST  
WI BY 15Z. FAIR WEATHER CUMULUS WILL DEVELOP AROUND 15Z  
BETWEEN 2,500 AND 4,000 FEET AND RISE TO 5-6 THOUSAND  
FEET LATE THIS AFTERNOON. PATCHY FOG EXPECTED LATE TONIGHT DUE  
TO THE COMBINATION OF LIGHT WINDS AND CLEAR TO PARTLY CLOUDY  
SKIES. FAIR WEATHER CUMULUS REDEVELOP ON THURSDAY.  
 
 
   
FIRE WEATHER  
 
ISSUED AT 229 AM CDT WED SEP 2 2026  
 
NOT AS WARM OR DRY ACROSS THE NORTH COMPARED TO TUESDAY. HIGHS  
ACROSS THE NORTH SHOULD CLIMB INTO THE UPPER 70S TO LOWER 80S  
WITH MINIMUM RELATIVE HUMIDITY VALUES BETWEEN 45 AND 55 PERCENT.  
UNFORTUNATELY, THE FAR NORTH IS LIKELY TO MISS OUT ON THE RAIN  
THIS MORNING. HOWEVER, THERE ARE PERIODIC CHANCES OF THUNDERSTORMS  
FROM LATE WEDNESDAY NIGHT THROUGH THE WEEKEND. HOPEFULLY ONE OF  
THE ROUNDS OF STORMS WILL BRING SOME MUCH NEEDED RAIN.  
MOISTURE FROM PRIOR RAINFALL SHOULD KEEP FUELS FROM REACHING  
CRITICAL THRESHOLDS. LOOKING FORWARD, EXTREME DROUGHT CONTINUES TO  
EXPAND OVER PORTIONS OF NORTHWEST WISCONSIN. WILL CONTINUE TO  
MONITOR FIRE WEATHER CONDITIONS THROUGHOUT THE MONTH, ESPECIALLY  
AFTER WE GET OUR FIRST FROST/FREEZE.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....ECKBERG  
AVIATION.......ECKBERG  
FIRE WEATHER...BERSCH/ECKBERG  
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