322  
FXUS63 KGRB 030716  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
216 AM CDT THU SEP 3 2026  
 
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE  
   
KEY MESSAGES  
 
- FIRST ROUND OF THUNDERSTORMS WILL MOVE ACROSS THE AREA THIS  
MORNING INTO EARLY THIS AFTERNOON. SOME OF THE STORMS COULD  
BECOME SEVERE WITH DAMAGING WINDS AND LARGE HAIL ALONG AND  
SOUTH OF HIGHWAY 29.  
 
- THERE MAY BE A LULL OR A BREAK IN THE THUNDERSTORM ACTIVITY  
DURING THE AFTERNOON, ANOTHER ROUND OF STRONG OR SEVERE  
THUNDERSTORMS IS POSSIBLE AGAIN LATE THIS AFTERNOON AND  
TONIGHT.  
 
- ABOVE NORMAL TEMPERATURES AND PERIODIC RAIN/STORM CHANCES WILL  
CONTINUE INTO THE WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 215 AM CDT THU SEP 3 2026  
 
ANOTHER WARM EARLY SEPTEMBER MORNING WITH TEMPERATURES IN THE 60S  
TO LOWER 70S. PATCHY FOG DEVELOPED IN SOME SPOTS AND WILL MONITOR  
THE LAKESHORE WHERE SOME PATCHY DENSE FOG MAY BE POSSIBLE ON LAKE  
MICHIGAN WHERE RECENT UPWELLING HAS COOLED OFF WATER  
TEMPERATURES.  
 
COMPLEX FORECAST THIS MORNING DEALING WITH POTENTIAL FOR STRONG  
OR SEVERE THUNDERSTORMS AT TIMES THROUGH LATE TONIGHT. FIRST  
ROUND OF THUNDERSTORMS EXPECTED TO MOVE ACROSS THE AREA THIS  
MORNING INTO EARLY THIS AFTERNOON. LOOKING AT TWO SIGNALS FOR  
THIS TO HAPPEN. LATEST MODELS INDICATED SCATTERED THUNDERSTORMS  
WILL DEVELOP BETWEEN 08Z AND 11Z ACROSS CENTRAL INTO EAST-CENTRAL  
WI IN RESPONSE TO A 40 KNOT/850 WARM ADVECTION ON A LOW LEVEL JET.  
ALSO WATCHING CONVECTION DEVELOPING ACROSS SOUTHERN MINNESOTA AND  
NORTHERN IOWA THAT WILL MAKE ITS WAY EASTWARD INTO OUR AREA LATER  
THIS MORNING. BUFKIT SOUNDINGS AT GREEN BAY INDICATED 40-50 KNOTS  
OF 0-6 KM SHEAR, SURFACE BASE CAPE OF 1,000-1,500 J/KG WITH MOST  
UNSTABLE CAPE VALUES AROUND 2,000 J/KG. SOME OF THE STORMS COULD  
BECOME STRONG OR SEVERE WITH DAMAGING WINDS, LARGE HAIL AND  
TORRENTIAL RAINFALL THIS MORNING.  
 
THERE WILL LIKELY BE A LULL OR BREAK IN THE THUNDERSTORM ACTIVITY  
THIS AFTERNOON. WITH THE BEST INSTABILITY TO OUR SOUTH, SCATTERED  
THUNDERSTORMS MAY REDEVELOP DURING THE PEAK HEATING OF THE DAY  
ACROSS CENTRAL INTO EAST-CENTRAL WI CLOSER TO THE BEST INSTABILITY.  
SOME OF THESE STORMS COULD BECOME SEVERE AS WELL. THE PLOT  
THICKENS TONIGHT WITH A COMPLEX OF THUNDERSTORMS DEVELOPING  
ACROSS THE UPPER MIDWEST. THE LATEST CANADIAN/ECMWF/NAM/GFS MODEL  
WOULD SUGGEST A COMPLEX OF THUNDERSTORMS WOULD WORK INTO THE AREA  
DURING THE LATE EVENING AND OVERNIGHT HOURS. HOWEVER, THERE ARE A  
FEW MESO MODELS WOULD SUGGEST DEVELOPMENT WOULD OCCUR DURING THE  
EVENING CLOSER TO THE BETTER INSTABILITY AND THEN DROP SOUTH INTO  
SOUTHERN WI.  
 
THERE ARE PERIODIC CHANCES OF THUNDERSTORMS WHILE ABOVE NORMAL  
TEMPERATURES WILL CONTINUE FRIDAY INTO EARLY NEXT WEEK AS THE  
SUMMER TIME PATTERN CONTINUES.  
 
 
   
AVIATION  
FOR 06Z TAF ISSUANCE  
ISSUED AT 1053 PM CDT WED SEP 2 2026  
 
A RATHER COMPLEX TAF PERIOD WITH UNCERTAINTY REGARDING FOG, LOW  
CLOUDS AND SHOWER/STORM CHANCES OVERNIGHT INTO THURSDAY. THE  
SIMPLE PART IS LATE THIS EVENING WHERE VFR CONDITIONS WILL  
PREVAIL AS MAINLY MID/HIGH CLOUDS DRIFT ACROSS THE REGION. THE  
LIGHT WINDS, CLEAR SKIES WILL ALLOW FOR SOME FOG TO FORM, BUT  
GUIDANCE NOT VERY BULLISH ON ANYTHING WIDESPREAD OR DENSE, WITH  
THE HIGHER CHANCES (UNDER 30% FOR UNDER 3 MILE VSBY) OVER EASTERN  
WI. HAVE INCLUDED MAINLY MVFR BR FOR NOW AND WILL MONITOR FOG  
TRENDS. LOW CLOUDS ARE ALSO POSSIBLE EARLY THURSDAY MORNING, WITH  
SOME GUIDANCE SHOWING A 700-2000 FT DECK, BUT AGAIN, NOT MUCH  
AGREEMENT TO HAVE MUCH CONFIDENCE THIS WILL OCCUR.  
 
FINALLY, THE SHOWER/STORM THREAT IS QUITE MUDDLED, BUT LATEST  
GUIDANCE IS INCREASING THE COVERAGE OF WITH ELEVATED CONVECTION  
POSSIBLE AS EARLY AS 07-09Z ACROSS CENTRAL AND EAST-CENTRAL WI,  
WITH A LARGER AREA POSSIBLE AFTER 12-13Z THURSDAY. DEPENDING ON  
WHAT OCCURS WITH THOSE AREA, ANOTHER ROUND OF SHOWERS AND STORMS  
MAY OR MAY NOT OCCUR THURSDAY AFTERNOON AND EVENING. THE END  
RESULT WILL BE PLENTY OF TEMPO AND PROB30 GROUPS TO ACCOUNT FOR  
THE MORE LIKELY PERIODS OF STORMS, BUT ADJUSTMENTS WILL BE NEEDED  
AS THE PICTURE WILL HOPEFULLY BECOME A LITTLE CLEARER. THERE  
REMAINS A LOW-END ~20% CHANCE THAT A STORM BECOMES STRONG TO  
SEVERE WITH STRONG WIND GUSTS AND HAIL BEING THE MAIN IMPACTS  
ALONG WITH HEAVY DOWNPOURS. WIND WILL REMAIN FAIRLY LIGHT AWAY  
FROM ANY STORM.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....ECKBERG  
AVIATION.......BERSCH  
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