072  
FXUS63 KGRB 031715  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
1215 PM CDT WED SEP 3 2025  
   
KEY MESSAGES
 
 
- SHOWERS AND A FEW EMBEDDED THUNDERSTORMS EXPECTED THIS MORNING.  
NO SEVERE STORMS ARE EXPECTED. LIGHT SHOWERS TO CONTINUE IN  
NORTH-CENTRAL WISCONSIN THROUGH TONIGHT.  
 
- COLDER AIR ARRIVES TODAY INTO TONIGHT. RECORD LOWS TEMPS  
POSSIBLE TONIGHT, WITH RECORD TO NEAR-RECORD LOW MAX TEMPS  
LIKELY THURSDAY AND FRIDAY. BELOW NORMAL TEMPS TO CONTINUE  
THROUGH THE WEEKEND.  
 
- ANOTHER ROUND OF RAIN ARRIVES THURSDAY EVENING AND LINGERS INTO  
EARLY FRIDAY. THIS SYSTEM WILL ALSO BRING GUSTY WINDS ON  
FRIDAY.  
 

 
   
DISCUSSION
 
 
ISSUED AT 406 AM CDT WED SEP 3 2025  
 
SHORT TERM...TODAY...TONIGHT...AND THURSDAY  
 
SHOWER/STORM TRENDS: A COUPLE AREAS/BROKEN LINES OF SHOWERS WILL  
SPREAD WEST TO EAST ACROSS THE AREA THIS MORNING AS A COLD FRONT  
AND SHORTWAVE MOVE THROUGH, AND AN UPPER LOW DROPS INTO SOUTHERN  
CANADA. MUCAPES UP TO 600 J/KG WILL STILL RESIDE AHEAD OF THE  
FRONT, SO A FEW NON-SEVERE STORMS WILL BE POSSIBLE THROUGH THE  
MORNING HOURS. A FEW POST-FRONTAL SHOWERS/SPRINKLES/DRIZZLE WILL  
BE POSSIBLE, ALONG WITH SOME INSTABILITY SHOWERS THIS AFTERNOON,  
MAINLY ACROSS CENTRAL AND NORTH-CENTRAL WI. THE MOST WIDESPREAD  
COVERAGE (50-75%) WILL BE OVER NORTH-CENTRAL WI, WHERE NORTHWEST  
WINDS FLOWING OVER LAKE SUPERIOR WILL PRODUCE SOME LAKE-ENHANCED  
SHOWERS. THIS ACTIVITY WILL CONTINUE OVER FAR NORTH-CENTRAL WI  
INTO TONIGHT, THEN TAPER OFF OVERNIGHT.  
 
TEMPERATURES & FROST POTENTIAL: THE WELL-ADVERTISED COOL DOWN  
STARTS TODAY AS CAA SPREAD ACROSS THE REGION BEHIND THE COLD  
FRONT AND AN UNUSUALLY COLD AIRMASS SETTLES OVER THE GREAT LAKES.  
MORNING HIGHS ARE LIKELY FOR MOST SPOTS TODAY (50S FAR NORTH, 60S  
ELSEWHERE), WITH STEADY OR SLOWLY FALLING TEMPS THIS AFTERNOON AS  
THE STRONGER CAA ARRIVES. IT WILL BE MUCH COLDER TONIGHT WITH  
LOWS IN THE 30S TO LOW 40S FOR MOST SPOTS, WITH SOME WARMER  
READINGS IN DOOR CO. HAVE CONTINUE TO MENTION PATCHY FROST OVER  
MUCH OF CENTRAL AND NORTH-CENTRAL WI. HOWEVER, PROSPECTS FOR  
WIDESPREAD FROST WILL BE HINDERED BY CLOUDS AND WINDS (ESPECIALLY  
JUST OFF THE SURFACE) KEEPING THINGS MIXED ENOUGH TO LIMIT FROST  
PRODUCTION. THAT SAID, THE NBM HAS THE HIGHEST PROBABILITIES  
(20-40%) OF GETTING BELOW FREEZING ACROSS MARATHON CO., WHICH  
COULD OCCUR IF WINDS DECOUPLE AND CLOUDS CLEAR SUFFICIENTLY. A  
FROST ADVISORY MAY BE NEEDED WHERE THIS OCCURS. WE WILL BE  
APPROACHING SOME RECORD LOW TEMPS TONIGHT, WITH MOST SITTING IN  
THE 30S. WAUSAU MAY BE THE MOST ACHIEVABLE WITH A RECORD LOW OF  
37, AND SHOULD HAVE THE LIGHTER WINDS AND FEWEST CLOUDS. THURSDAY  
WILL BE A CHILLY DAY WITH HIGHS IN THE 50S TO LOW 60S, ALONG WITH  
A WEST WIND GUSTING TO 25 MPH. RECORD LOW MAX TEMPS FOR SEPT 4  
WILL BE IN JEOPARDY, AS ALL SITES HAVE RECORDS IN THE MID 50S TO  
60.  
 
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY  
 
PRECIPITATION CHANCES...A QUICK-MOVING LOW PRESSURE SYSTEM WILL  
DIVE SOUTHEAST ACROSS THE DAKOTAS/MN INTO WI BY THURSDAY  
EVENING, TRACK ACROSS THE STATE, AND DEPART TO THE EAST BY LATE  
FRIDAY MORNING. DESPITE SLIGHT DISAGREEMENTS WITH THE EXACT TRACK  
OF THE LOW, WIDESPREAD RAINFALL IS EXPECTED. RAINFALL AMOUNTS  
SHOULD REMAIN LESS THAN 1 INCH (AND LIKELY BELOW 0.75 INCHES)  
GIVEN PWATS OF 0.75-1.00 INCHES. ADDITIONAL LIGHT RAIN SHOWERS ARE  
POSSIBLE IN FAR NORTH- CENTRAL WI ON FRIDAY WITH LINGERING LOW-  
LEVEL MOISTURE AND SLIGHTLY FAVORABLE WEST-NORTHWEST WINDS. MODELS  
INDICATE ADDITIONAL LIGHT SHOWER ACTIVITY ON SATURDAY ASSOCIATED  
WITH A WEAK EMBEDDED MID- LEVEL SHORTWAVE, BUT IMPACTS WILL BE  
MINIMAL. DRY WEATHER RESULTS SUNDAY INTO MONDAY AS SURFACE HIGH  
PRESSURE SHIFTS OVER THE AREA. MODELS THEN INDICATE THE NEXT  
CHANCE FOR PRECIP SOMETIME MIDWEEK.  
 
WIND...ACCOMPANYING THE QUICK-MOVING LOW PRESSURE SYSTEM WILL BE A  
TIGHT PRESSURE GRADIENT WITH STRONG SOUTHWESTERLY LOW-LEVEL WINDS  
AHEAD OF THE LOW THURSDAY EVENING, TURNING WESTERLY WITH CAA ON  
FRIDAY. AS A RESULT, GUSTS OF 25 TO 35 MPH ARE POSSIBLE THROUGHOUT  
THIS TIME FRAME, WITH THE HIGHEST GUSTS ON FRIDAY. WINDS WILL  
SUBSIDE FRIDAY EVENING.  
 
TEMPERATURES...AN ABNORMALLY COLD AIRMASS WILL REMAIN IN PLACE  
THROUGH SATURDAY, LEAVING SOME RECORD LOW HIGHS POTENTIALLY IN  
JEOPARDY FOR SEPT 5 (FRIDAY). FRIDAY'S HIGH TEMPERATURES WILL BE  
ABOUT 15 TO 20 DEGREES BELOW NORMAL WITH VALUES RANGING FROM THE  
LOW 50S TO LOW 60S. TEMPERATURES WILL GRADUALLY WARM BY A FEW  
DEGREES EACH DAY THROUGHOUT THE WEEKEND AND INTO EARLY NEXT WEEK,  
BUT WILL OVERALL REMAIN BELOW NORMAL.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
 
 
ISSUED AT 1215 PM CDT WED SEP 3 2025  
 
THE COLD FRONT HAS CLEARED THE AREA WITH GUSTY WEST TO NORTHWEST  
WINDS IN ITS WAKE. THE CUMULUS FIELD WILL TREND TOWARDS VFR AT  
ALL SITES THIS AFTERNOON WITH SOME CLEARING EXPECTED THIS  
EVENING, BUT MVFR CONDITIONS ALONG WITH SOME SHOWERS WILL LINGER  
INTO TONIGHT ACROSS FAR NORTH-CENTRAL WISCONSIN. WINDS WILL  
SUBSIDE THIS EVENING WITH SOME DIURNAL INCREASE ON THURSDAY AS  
MIXING COMMENCES.  
 

 
   
MARINE
 
 
ISSUED AT 406 AM CDT WED SEP 3 2025  
 
SOUTHWEST WINDS WILL CONTINUE TO GUST UP TO AROUND 20 KTS EARLY  
THIS MORNING AHEAD OF A COLD FRONT. THIS WILL KEEP WAVES MAINLY IN  
THE 1-4 FT RANGE. WINDS WILL SHIFT TO THE NORTHWEST LATE THIS  
MORNING AND AFTERNOON, WITH FORECAST SOUNDINGS SHOWING GUSTS TO  
25 KTS LIKELY AS THE STRONGER CAA ARRIVES. HIGHEST WINDS WILL  
LIKELY BE ON THE BAY AND NEAR DEATH'S DOOR WHERE THE WATERS ARE  
THE WARMEST. WILL HOIST A SMALL CRAFT ADVISORY FOR THIS AFTERNOON  
FOR THESE LOCATIONS. ANOTHER PERIOD OF GUSTY SOUTHWEST/WEST WINDS  
ARE EXPECTED ON THURSDAY EVENING INTO FRIDAY, WITH A SMALL CRAFT  
ADVISORY LIKELY BEING NEEDED. A FEW GALE FORCE GUSTS TO AROUND 35  
KTS ARE POSSIBLE ON FRIDAY AS WELL WITH NBM PROBABILITIES FOR  
GALES OF 40-70% ALONG THE NEARSHORE WATERS.  
 
AS FOR WATERSPOUT POTENTIAL, WILL CONTINUE TO CARRY A CHANCE THIS  
MORNING AS THE COLD FRONT WORKS ACROSS THE BAY/LAKE. AS THE FRONT  
EXITS TO THE EAST, THE WATERSPOUT THREAT WILL BE NON-ZERO DUE TO  
THE COLDER AIR ALOFT, BUT THINK THE BETTER CHANCES SHIFT OVER THE  
OPEN WATERS AND MICHIGAN SHORELINES AS AN INVERSION WILL LIMIT  
BETTER CONVECTIVE CLOUD HEIGHTS FROM MATERIALIZING, SO WILL NOT  
INCLUDE THIS AFTERNOON INTO TONIGHT. THERE IS ANOTHER SMALL CHANCE  
FOR WATERSPOUTS LATE THURSDAY INTO FRIDAY MORNING AS ANOTHER LOW  
PRESSURE SYSTEM TRACKS THROUGH THE AREA.  
 

 
   
GRB WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ521-  
522-541.  
 

 
 

 
 
DISCUSSION...BERSCH/KRUK  
AVIATION...JM  
MARINE...BERSCH/KRUK  
 
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