017  
FXUS63 KGRB 171804  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
104 PM CDT SUN AUG 17 2025  
 
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE  
   
KEY MESSAGES
 
 
- ACTIVE WEATHER RETURNS EARLY MONDAY. THERE IS POTENTIAL FOR A  
FEW STRONG OR SEVERE STORMS IN THE AFTERNOON AND EVENING.  
 
- RAINFALL ON MONDAY MAY BE HEAVY AT TIMES. PROBABILITY OF  
EXCEEDING AN INCH OF RAIN IS AROUND 30-50% FOR PORTIONS OF  
CENTRAL WISCONSIN.  
 
- A MUCH DRIER PATTERN IS SET TO ARRIVE TUESDAY THROUGH NEXT  
WEEKEND.  
 

 
   
DISCUSSION
 
 
ISSUED AT 359 AM CDT SUN AUG 17 2025  
 
FOCUS OF THE FORECAST REMAINS ON ACTIVE WEATHER FOR LATE TONIGHT  
AND AGAIN ON MONDAY.  
 
TODAY AND TONIGHT...  
QUIET CONDITIONS ARE EXPECTED ACROSS THE REGION THROUGH THE  
AFTERNOON AND EARLY EVENING AS WARM FRONT REMAINS SOUTH OF THE  
REGION DURING THE DAY. SUNSHINE MAY EVEN WORK ITS WAY INTO THE  
AREA AT TIMES IN THE MORNING AND EARLY AFTERNOON, ESPECIALLY FOR  
FAR NORTHERN WISCONSIN ALONG THE UPPER PENINSULA BORDER. BY THE  
OVERNIGHT PERIOD, WIDESPREAD CLOUD COVER WILL RETURN TO THE REGION  
AS THE WARM FRONT WORKS ITS WAY NORTHWARDS AGAIN, BUT MODELS HAVE  
DELAYED THE ONSET OF RAIN UNTIL WELL AFTER MIDNIGHT AS THE UPPER  
LEVEL SHORTWAVE CROSSES INTO THE REGION MONDAY MORNING.  
 
MONDAY...  
RAIN AND A FEW STORMS WILL MOVE INTO THE REGION MONDAY MORNING,  
GETTING INTO PORTIONS OF CENTRAL AND NORTH-CENTRAL WISCONSIN BY  
DAYBREAK. FROM THERE, RAIN WILL GRADUALLY EXPAND EASTWARDS AS A  
MORE ORGANIZED SHORTWAVE CROSSES THE AREA IN THE LATTER PART OF  
THE DAY. SEVERE WEATHER POTENTIAL FOR MONDAY WILL BE LARGELY  
CONDITIONAL ON HOW FAR NORTH THE WARMER AND MORE UNSTABLE AIR  
GETS EARLY ON AND HOW MUCH INSTABILITY WE ARE ABLE TO BUILD INTO  
THE REGION BY MONDAY AFTERNOON AND EVENING AS THE BETTER SHEAR  
ARRIVES. THE LOCATION OF THE WARM FRONT WILL BEAR WATCHING OVER  
THE NEXT COUPLE FORECAST CYCLES. IF THE FRONT DOES GET INTO THE  
AREA AND WE GET SUFFICIENT INSTABILITY RESERVOIR BY THE ARRIVAL  
OF THE SHORTWAVE, MAIN SEVERE THREAT WILL BE WIND, BUT SOME HAIL  
MAY ALSO BE POSSIBLE AT TIMES. RAIN AND STORMS MAY LAST INTO THE  
OVERNIGHT PERIOD, BUT QUIETER CONDITIONS ARE EXPECTED TO RETURN AS  
COOLER AND MORE DRY AIR PUSHES BACK INTO THE REGION. RAINFALL  
AMOUNTS FOR THIS TIME PERIOD ARE LESS IMPRESSIVE THAN THEY WERE  
EARLIER IN THE WEEKEND, WITH ONLY A FEW SPOTS GETTING TO AROUND  
30-50% OF EXCEEDING AN INCH OF RAINFALL AT THIS TIME, MAINLY IN  
POTIONS OF CENTRAL WISCONSIN. AGAIN, IF THE FRONT SHOWS SIGNS OF  
PUSHING NORTHWARDS, WOULD EXPECT THIS TO INCREASE BUT GIVEN THE  
LONGER DRY PERIOD BETWEEN RAIN EVENTS FLASH FLOODING RISK IS LOW.  
 
REST OF THE FORECAST...  
TUESDAY WILL HERALD A PATTERN SHIFT FROM THE FAIRLY ACTIVE PATTERN  
OVER THE WEEKEND TO A MORE DRY PATTERN THAT WILL LAST THE REST OF  
THE FORECAST PERIOD THROUGH NEXT WEEKEND. TEMPERATURES DURING THIS  
TIME WILL BE CLOSER TO NORMAL, WITH HIGHS MAINLY IN THE 70S DURING  
THE WEEK ALONG WITH A FEW SPOTS GETTING INTO THE LOWER 80S.  
 

 
   
AVIATION
 
FOR 18Z TAF ISSUANCE  
ISSUED AT 104 PM CDT SUN AUG 17 2025  
 
NORTHEAST WINDS HAVE BROUGHT A BKN LOW STRATUS DECK INLAND FROM  
LAKE MICHIGAN EARLY THIS AFTERNOON, RESULTING IN PERIODS OF MVFR  
CIGS TO THE EAST-CENTRAL WI TAF SITES. MEANWHILE, HIGH CLOUDS  
SPREAD EASTWARD OVER THE CENTRAL WI TAF SITES EARLY THIS  
AFTERNOON, WITH SOME LINGERING LOWER CLOUDS MAINLY BETWEEN  
4000-7000 FT AGL. ANTICIPATE THE LOW CLOUDS OFF OF LAKE MICHIGAN  
WILL DISSIPATE/ERODE BY LATE THIS AFTERNOON AS THE HIGH CLOUDS  
CONTINUE TO SPREAD EASTWARD.  
 
CLOUD COVER WILL INCREASE THROUGH LATE THIS EVENING AND OVERNIGHT  
AS THE NEXT CHANCE FOR SHOWERS AND STORMS ARRIVES FROM THE WEST.  
THE EXACT ONSET OF THE SHOWERS AND STORMS IS STILL UNCERTAIN AS  
SOME SHORT-RANGE MODELS INDICATE A LEADING LINE OF SHOWERS AND  
STORMS MAY MOVE OVER THE TAF SITES FROM WEST TO EAST ROUGHLY  
BETWEEN 07Z TO 14Z BEFORE THE MAIN LINE OF SHOWERS AND STORMS  
MOVES OVER THE AREA FROM WEST TO EAST ROUGHLY BETWEEN 12Z TO 18Z.  
HAVE ACCOUNTED FOR THE POTENTIAL LEADING CONVECTION WITH PROB30  
GROUPS AT ALL TAF SITES, WITH TEMPO GROUPS FOR THE MAIN LINE. ANY  
STORMS WILL LIKELY BE ACCOMPANIED BY AT LEAST MVFR CIGS AND  
VSBYS.  
 
BREEZY EAST TO SOUTHEAST WINDS WILL PREVAIL THROUGHOUT THIS TAF  
PERIOD WITH GUSTS POTENTIALLY REACHING 20 KTS AT TIMES.  
 

 
   
GRB WATCHES/WARNINGS/ADVISORIES
 
 
BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR WIZ022.  
 
BEACH HAZARDS STATEMENT THROUGH MONDAY AFTERNOON FOR WIZ040-050.  

 
 

 
 
DISCUSSION.....UHLMANN  
AVIATION.......KRUK  
 
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