755  
FXUS63 KGRB 122325  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
625 PM CDT SAT SEP 12 2026  
 
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE  
   
KEY MESSAGES
 
 
- THE FIRST WIDESPREAD FROST OF THE SEASON IS EXPECTED ACROSS  
THE NORTH LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. A  
FEW OF THE TYPICAL COLDER LOCATIONS COULD DROP TO OR SLIGHTLY  
BELOW FREEZING FOR A FEW HOURS.  
 
- A ROUND OR TWO OF HEAVY RAIN AND STORMS IS POSSIBLE MONDAY INTO  
TUESDAY. THE SEVERE WEATHER THREAT IS LOW.  
 
- HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY MONDAY AFTERNOON  
INTO TUESDAY AFTERNOON DUE TO GUSTY SOUTHERLY WINDS OR HIGH  
WAVES.  
 
- HIGH WAVES WILL LEAD TO AN INCREASED RISK OF RIP CURRENTS AT  
LAKE MICHIGAN BEACHES MONDAY AFTERNOON INTO TUESDAY AFTERNOON.  
 

 
   
DISCUSSION
 
 
ISSUED AT 139 PM CDT SAT SEP 12 2026  
 
A COLD FRONT MOVING ACROSS NORTHEAST WI THIS AFTERNOON WAS  
PRODUCING A BAND OF THICK CLOUDS. AS THE FRONT PASSES, SKIES  
WILL CLEAR WITH MOSTLY SUNNY SKIES EXPECTED. TRANQUIL CONDITIONS  
PREVAIL TONIGHT WITH A PREVIEW OF FALL LIKE TEMPERATURES WITH LOWS  
IN THE 40S TO AROUND 50. THE EXPECTED FGEN BAND FOR TONIGHT WILL  
PASS TO THE SOUTH OF THE AREA. ON SUNDAY, PER COORDINATION WITH  
SURROUNDING OFFICES TO THE NORTH AND WEST, LOWERED HIGH TEMPERATURES  
A FEW DEGREES, ESPECIALLY ACROSS THE NORTH BASED ON THE LATEST  
MET/MAV GUIDANCE. THIS WILL MEAN HIGH TEMPERATURES WILL BE MAINLY  
IN THE 60S ON SUNDAY, WITH A FEW LOWER 70S ACROSS EAST-CENTRAL  
WI. FOR SUNDAY NIGHT, HIGH PRESSURE CENTERED ACROSS THE AREA  
COMBINED WITH LIGHT WINDS AND CLEAR SKIES SHOULD BRING THE FIRST  
WIDESPREAD FROST OF THE SEASON ACROSS THE NORTH. SOME OF OUR  
COLDER SPOTS COULD DROP TO OR A FEW DEGREES BELOW FREEZING FOR A  
COUPLE OF HOURS AROUND SUNRISE.  
 
STRONG LOW PRESSURE ACROSS THE NORTHERN PLAINS WILL MOVE NORTHEAST  
INTO CANADA WITH A TRAILING COLD FRONT APPROACHING WISCONSIN ON  
MONDAY. CLOUDS WILL BE ON THE INCREASE WITH RAIN ARRIVING  
DURING THE AFTERNOON FOR LOCATIONS MAINLY WEST OF THE FOX VALLEY.  
THIS IN RESPONSE TO AN INCREASING 850MB LOW LEVEL JET AND WARM  
ADVECTION. MEANWHILE, A WAVE OF LOW PRESSURE WILL MOVE ALONG THE  
FRONT MONDAY NIGHT AS IT MOVES ACROSS THE REGION. PRECIPITABLE  
WATER NEAR 2" ARE NEAR THE TOP OF THE CHARTS FOR THIS TIME OF  
YEAR. SOME COMPLEXITIES TO THE FORECAST AS THE NBM PROBABILITIES  
OVER AN INCH ARE 50-80% FROM CENTRAL INTO NORTHEAST WI WHILE LREF  
PROBABILITIES ARE IN THE 20-50%. HIGHEST PROBABILITIES IN BOTH  
SOLUTIONS ARE OUT TOWARDS WAUSAU AND WISCONSIN RAPIDS. THE RISK  
OF SEVERE WEATHER APPEARS TO STAY JUST TO OUR SOUTH. ANY LINGERING  
SHOWERS SHOULD END TUESDAY MORNING ACROSS NORTHEAST WI.  
 
THE BOUNDARY SHOULD FAR ENOUGH SOUTH FOR TUESDAY NIGHT INTO  
WEDNESDAY MORNING FOR DRY CONDITIONS. BEYOND THAT, THERE COULD BE  
A FEW ROUNDS OF SHOWERS AND PERHAPS A FEW THUNDERSTORMS WEDNESDAY  
AFTERNOON THROUGH THURSDAY. BY FRIDAY, THE CANADIAN/ECMWF HAVE A  
WETTER SOLUTION COMPARED TO THE GFS. BELOW NORMAL TEMPS FOR SUNDAY  
INTO MONDAY, THEN SEASONABLE TEMPS FOR THE REST OF THE WORK WEEK.  
 

 
   
AVIATION
 
FOR 00Z TAF ISSUANCE  
ISSUED AT 622 PM CDT SAT SEP 12 2026  
 
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH INTERVALS OF  
SCT-BKN MID AND HIGH CLOUDS. VFR CU (040-060) POSSIBLE AT TIMES  
ON SUNDAY AS WELL. LIGHT NORTHWEST WINDS INCREASE TO 10-20 KTS ON  
SUNDAY, WITH GUSTS UP TO 25 KTS NOT OUT OF THE QUESTION.  
 

 
   
MARINE
 
 
ISSUED AT 139 PM CDT SAT SEP 12 2026  
 
ANOTHER PERIOD OF GUSTY SOUTHERLY WINDS WILL LEAD TO INCREASING  
WAVES, ALONG WITH AN INCREASING RISK OF RIP CURRENTS MONDAY INTO  
TUESDAY. A SMALL CRAFT ADVISORY OR GALE WARNING AND BEACH HAZARD  
STATEMENTS WILL LIKELY BE NEEDED.  
 

 
   
GRB WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
DISCUSSION.....ECKBERG  
AVIATION.......JLA  
MARINE.........ECKBERG  
 
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