072  
FXUS63 KGRB 140641  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
141 AM CDT FRI AUG 14 2026  
 
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE  
   
KEY MESSAGES  
 
- SCATTERED SHOWERS (30-55%) LATE TONIGHT THROUGH SATURDAY  
AFTERNOON. LATEST TREND IS DOWNWARD FOR RAIN CHANCES AND RAIN  
AMOUNTS ON SATURDAY.  
 
- ANOTHER ROUND OF SHOWERS (30-50%) AND A FEW THUNDERSTORMS  
(10-20%) SATURDAY NIGHT AS COLD FRONT MOVES THROUGH. LOCALLY  
HEAVY RAIN POSSIBLE.  
 
- DRYING OUT LATER SUNDAY INTO MONDAY WITH NEXT CHANCE FOR SHOWERS  
AND SOME STORMS TUESDAY INTO WEDNESDAY.  
 
 
   
DISCUSSION  
 
ISSUED AT 140 AM CDT FRI AUG 14 2026  
 
DAY TODAY, SOME SHOWERS ARRIVE LATE TONIGHT: WEAK HIGH PRESSURE  
OVERHEAD WITH POCKETS OF MID CLOUD AND LOCALLY DENSE FOG. THUS FAR  
THE FOG IS VARIABLE IN COVERAGE TO HAVE ANYTHING MORE THAN SPS  
OUT, BUT WILL MONITOR TO SEE IF A DENSE FOG ADVISORY IS NEEDED  
ANYWHERE. A LULL IN CLOUD COVER THIS MORNING, THEN CLOUDS INCREASE,  
THICKEN LATE TODAY AHEAD OF SOUTHERN STREAM SHORTWAVE THAT ARRIVES  
LATE TONIGHT. EASTERLY WINDS RESULT IN WARMEST READINGS TODAY  
CENTRAL TO NORTH-CENTRAL WI WITH HIGHS IN THE LOWER, MAYBE MID  
80S. FEW SHOWERS MAKE IT INTO SOUTHERN TIER OF COUNTIES VERY LATE  
TONIGHT AHEAD OF THE WAVE.  
 
SHOWERS/STORMS SATURDAY AND SATURDAY NIGHT: TREND THAT IS EMERGING  
IS MOST GUIDANCE (EXCEPT ESPECIALLY THE NAM) IS TO KEEP MAJORITY  
OF WIDESPREAD SHOWERS ON SATURDAY TO THE SOUTH CLOSER TO THE  
HIGHER INSTABILITY AND CONVERGENCE ON NOSE OF LLJ. THIS SHOWS UP  
NICELY WHEN LOOKING AT HREF 1HR PROBS OF 0.01" WHICH SHOWS HIGHER  
PROBABILITIES STAYING OVER FAR SOUTHERN WI, NORTHERN IL DURING  
THE MORNING. INCREASING MOISTURE AND LIFT ON THE NORTH EDGE OF  
THIS COULD STILL PRODUCE SCATTERED SHOWERS, WITH THE GREATEST  
FOCUS SOUTHERN FOX VALLEY TO THE LAKESHORE. IF THIS TREND CONTINUES  
THOUGH, SOME LOCATIONS COULD STAY DRY DURING THE DAYTIME ON SATURDAY,  
WHICH LOOKED VERY UNLIKELY A COUPLE DAYS AGO. MAIN FRONT DOES  
SWING THROUGH ON SATURDAY NIGHT WITH PRIMARY SHORTWAVE OVER LAKE  
SUPERIOR. THIS IS LIKELY WHEN MOST LOCATIONS WILL SEE AT LEAST  
SCATTERED SHOWERS. GIVEN BOUNDARY IS INTERACTING WITH PWATS OVER  
1.8" (95+ PERCENTILE) AND SLOWER MBE VECTORS ARE FORECAST,  
LOCALLY HEAVY RAIN MAY OCCUR SATURDAY NIGHT.  
 
DRY LATER SUNDAY INTO MONDAY: FRONT CLEARS EASTERN WI BY SUNDAY  
MORNING. A FEW SHOWERS MAY LINGER DURING THE MORNING, BUT MAINLY A  
DRY DAY IS EXPECTED. LOOKS KIND OF BREEZY WITH PEAK GUSTS OVER 20  
MPH AT TIMES AS WINDS SHIFT NORTHWEST. DESPITE BEING BEHIND THE  
FRONT, IT COULD ACTUALLY BE WARMER ON SUNDAY WITH MORE SUNSHINE  
AND MIXING. NOT AS HUMID AS SATURDAY, BUT DEWPOINTS WILL STILL  
LINGER INTO THE MID 60S OVER EAST-CENTRAL MOST OF THE DAY. MONDAY  
WILL BE NOTICEABLY LESS HUMID ACROSS THE BOARD.  
 
NEXT CHANCE FOR RAIN IS TUESDAY...NORTHWEST FLOW BRINGS ANOTHER  
SHORTWAVE TROUGH AND COLD FRONT THROUGH LEADING TO NEXT CHANCE  
FOR ORGANIZED SHOWERS AND SOME THUNDER TUESDAY. GREATEST INSTABILITY  
TUESDAY AFTERNOON REMAINS SOUTHWEST OF OUR AREA, SO RISK FOR  
SEVERE STORMS LOOKS LOWER WHICH ALIGNS WITH VARIOUS ML  
PROJECTIONS THAT SHOWS GREATER SIGNAL SOUTHERN MN INTO IA.  
MODELS/ENSEMBLES ARE PICKING UP ON ANOTHER WAVE SLIDING IN FROM  
THE WEST INTERACTING WITH THE FRONTAL BOUNDARY TO KEEP SHOWERS AND  
SOME STORMS LINGERING LATER TUESDAY NIGHT INTO WEDNESDAY. WITH  
PWATS UP TO 1.5 THROWN INTO THE MIX, PROBABILITIES OF 0.5 INCH/1.0  
INCH OF QPF HAVE STEADILY INCREASED OVER THE LAST FEW RUNS. ECMWF  
EFI/SOT NOW HAS SOME SIGNAL FOR HEAVY RAIN. WPC IS ALSO NOW  
INDICATING A MARGINAL TO SLIGHT (LEVEL 1/2 OF 4) FOR EXCESSIVE  
RAIN DURING THIS TIME. AS WE SAW WITH THE EVOLUTION OF THIS WEEKENDS  
HIGHER RISKS THAT EVENTUALLY SHIFTED SOUTH, THESE AREAS CAN SHIFT  
WITH TIME, BUT WILL BE SOMETHING TO WATCH AS WE GET CLOSER TO THIS  
TIME FRAME.  
 
COOLER AIR PUSH BEHIND THIS SYSTEM FOR THE END OF THE WEEK WITH  
HIGHS SETTLING INTO THE LOWER TO MIDDLE 70S.  
 
 
   
AVIATION  
FOR 06Z TAF ISSUANCE  
ISSUED AT 1041 PM CDT THU AUG 13 2026  
 
PATCHY AREAS OF FOG ARE BEGINNING TO DEVELOP ACROSS PARTS OF EAST-  
CENTRAL WI LATE THIS EVENING. PERIODS OF IFR VSBYS ARE POSSIBLE AT  
GRB, ATW, AND MTW, THROUGH ABOUT 10Z. ONCE THE FOG CLEARS VFR  
CONDITIONS ARE EXPECTED FOR THE REST OF FRIDAY.  
 
LIGHT AND VARIABLE WINDS ARE EXPECTED OVERNIGHT. FRIDAY EASTERLY  
WINDS WILL INCREASE GRADUALLY WITH GUSTS UP TO 15KTS POSSIBLE.  
 
BEYOND THE TAF PERIOD A ROUND OF SCATTERED SHOWERS AND ISOLATED  
STORMS IS EXPECTED TO MOVE INTO THE REGION SATURDAY MORNING. PERIOD  
REDUCTIONS IN VISIBILITY ALONG WITH LIGHTNING ARE EXPECTED TO BE THE  
MAIN AVIATION IMPACTS.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....JLA  
AVIATION.......GK  
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