422  
FXUS63 KGRB 121904  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
204 PM CDT MON MAY 12 2025  
 
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE  
   
KEY MESSAGES
 
 
- ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS REMAIN TODAY DUE TO  
DRY FUELS, LOW HUMIDITY, AND WINDS GUSTING TO AROUND 15 MPH. A  
RED FLAG WARNING REMAINS IN NORTHERN WI UNTIL 9:00 PM.  
 
- THERE IS A MEDIUM CHANCE (20-40%) OF SCATTERED SHOWERS AND  
THUNDERSTORMS TUESDAY AND WEDNESDAY, ESPECIALLY DURING THE  
AFTERNOON.  
 
- RAIN AND STORMS ARE MOST LIKELY (50-80% CHANCE) THURSDAY  
AFTERNOON AND EVENING. STRONG OR SEVERE STORMS WILL BE POSSIBLE  
WITH THE PASSAGE OF A COLD FRONT.  
 

 
   
DISCUSSION
 
 
ISSUED AT 204 PM CDT MON MAY 12 2025  
 
FIRE WEATHER CONDITIONS REMAIN THE FOCUS THROUGH TOMORROW WITH A  
DAY AIRMASS IN PLACE. A RED FLAG WARNING REMAINS IN EFFECT THROUGH  
MID-EVENING ACROSS NORTH-CENTRAL WISCONSIN WHERE CONDITIONS ARE  
MOST FAVORABLE FOR FIRES TO EASILY START AND SPREAD QUICKLY. THERE  
IS SOME IMPROVEMENT TOMORROW, BUT CONDITIONS REMAIN ELEVATED  
ACROSS NORTH-CENTRAL WI WHERE FUELS ARE THE MOST DRY AND MINIMUM  
RHS ARE IN THE 30-40% RANGE. SEE FIRE WEATHER SECTION FOR MORE  
DETAILS.  
 
SKIES WILL REMAIN SUNNY THROUGH THE REST OF THE AFTERNOON. THEN,  
OUTER CLOUDS FROM A SYSTEM ACROSS THE SOUTHEAST U.S. WILL START TO  
ROTATE INTO THE AREA THIS EVENING AND OVERNIGHT, BRINGING PARTLY  
SUNNY TO MOSTLY CLOUDY SKIES ACROSS THE AREA THE NEXT COUPLE DAYS.  
SOME PATCHY FOG IS POSSIBLE ACROSS EAST-CENTRAL WI EARLY TUESDAY  
MORNING. A FEW RAIN SHOWERS AND ISOLATED STORMS ARE ALSO POSSIBLE  
DURING THE LATE MORNINGS AND AFTERNOON AS DAYTIME HEATING  
DEVELOPS. INSTABILITY IS AROUND 200-600 J/KG TUESDAY, AND 200-800  
J/KG ON WEDNESDAY. THEREFORE, EXPECT ANY STORMS TO BE ISOLATED AND  
NON- SEVERE. CAMS WOULD ALSO SUPPORT THIS.  
 
AS THE EASTERN U.S. SYSTEM CONTINUES TO DEPART, THIS ALLOWS FLOW  
TO BECOME MORE PROGRESSIVE WITH A STRONGER SYSTEM AND COLD FRONT  
APPROACHING AND MOVING THROUGH THURSDAY INTO FRIDAY. PERIODS OF  
RAIN ARE LIKELY (50-80% CHANCE) WITH THIS SYSTEM, AND STRONG OR  
SEVERE THUNDERSTORMS ARE A POSSIBILITY THURSDAY AFTERNOON AND  
EVENING AS MUCAPES BUILDING TO 1000-3000 J/KG DEPENDING ON THE  
MODEL/GUIDANCE. DEEP SHEAR IS AROUND 40 KTS AND MID- LEVEL LAPSES  
RATES OF AROUND 7.0-7.5 C/KM.  
 
DRY SLOT MOVES THROUGH LATE THURSDAY NIGHT/FRIDAY MORNING, WITH  
ADDITIONAL ON/OFF RAIN CHANCES ON FRIDAY AFTERNOON INTO SATURDAY  
ON THE BACK SIDE OF THE SYSTEM. HOWEVER, INSTABILITY WILL BE  
LIMITED BY THIS POINT. CANNOT RULE OUT SOME ISOLATED THUNDER, BUT  
MAINLY LOOKING AT RAIN.  
 
TEMPERATURES WILL BE MILD TONIGHT IN THE UPPER 40S TO MIDDLE 50S,  
AND THEN RISE INTO THE MIDDLE 70S TO LOW 80S TOMORROW AWAY FROM  
LAKE MICHIGAN. TEMPS COOL DOWN BEHIND THE LATE WEEK FRONT WITH  
READINGS AOB NORMAL FOR MID-MAY.  
 

 
   
AVIATION
 
FOR 18Z TAF ISSUANCE  
ISSUED AT 1241 PM CDT MON MAY 12 2025  
 
SKY...VFR FLYING CONDITIONS WILL PERSIST TODAY AND THROUGH MUCH  
OF TONIGHT, WITH LOW CLOUDS ARRIVING IN EAST-CENTRAL WI NEAR  
DAYBREAK TUESDAY. LOW CLOUDS AND PATCHY FOG WILL CREATE MVFR AND  
TEMPORARY IFR CONDITIONS ACROSS THE FOX VALLEY AND EAST- CENTRAL  
WI TUESDAY MORNING, AND THEN IMPROVE IN THE AFTERNOON. FARTHER  
WEST (CENTRAL WI) MORE CLOUDS WILL ARRIVE, BUT CONDITIONS WILL  
REMAIN VFR.  
 
WINDS...A FEW SOUTHERLY WIND GUSTS UP TO 20 KTS WERE OCCURRING  
EARLY THIS AFTERNOON. CONTINUED WITH THIS TREND THROUGH THE LATE  
AFTERNOON, WITH WINDS BECOMING LIGHT THIS EVENING.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 204 PM CDT MON MAY 12 2025  
 
RED FLAG WARNING CONTINUES FOR COUNTIES IN NORTHERN WISCONSIN  
THROUGH 9:00 PM. RELATIVE HUMIDITY VALUES HAVE RANGED FROM 12 TO  
22% FOR COUNTIES IN THIS AREA, WITH SOUTHERLY WINDS AROUND 12 MPH  
AND GUSTS TO 20 MPH. TEMPERATURES WERE ALSO IN THE LOW 80S.  
FARTHER SOUTH, MAINTAIN SPS FOR ELEVATED FIRE WEATHER CONDITIONS  
WHERE RHS WERE A LITTLE HIGHER.  
 
FIRE WEATHER CONDITIONS ARE ELEVATED ACROSS NORTH-CENTRAL  
WISCONSIN ON TUESDAY WITH MINIMUM RHS IN THE 30-40% RANGE. WINDS  
WILL BE A LITTLE LIGHTER AROUND 5-10 MPH WITH GUSTS TO AROUND 17  
MPH, AND HIGH TEMPS IN THE LOW 80S. FARTHER SOUTH ACROSS THE REST  
OF THE GRB FORECAST AREA RHS ARE IN THE 40-60% RANGE AND CLOUDS  
WILL MAKE FOR SLIGHTLY COOLER TEMPS IN THE 70S.  
 

 
   
GRB WATCHES/WARNINGS/ADVISORIES
 
 
RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR WIZ005-010>013-  
018-019.  

 
 

 
 
DISCUSSION.....KLJ  
AVIATION.......KLJ  
FIRE WEATHER...KLJ  
 
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