616  
FXUS63 KMKX 090942  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
442 AM CDT WED SEP 9 2026  
   
KEY MESSAGES  
 
- SHOWERS WITH ISOLATED EMBEDDED THUNDERSTORMS REMAIN POSSIBLE  
THIS MORNING, DRY WEATHER AND DECREASING CLOUDS FROM MIDDAY  
ONWARDS.  
 
- WARM TEMPERATURES WITH LOW HUMIDITY THROUGH THE SECOND HALF OF  
THE WORK WEEK.  
 
- NEXT CHANCES FOR STORMS DEVELOP LATE FRIDAY NIGHT INTO  
SATURDAY MORNING, AND AGAIN SUNDAY INTO MONDAY.  
 
 
   
UPDATE  
 
ISSUED 440 AM CDT WED SEP 9 2026  
 
AS I WRITE THIS, THE RADAR IS CURRENTLY CLEAR OVER SOUTHERN WI,  
WITH GOES NIGHTTIME MICROPHYSICS SATELLITE IMAGERY SHOWING SOME  
ATTEMPTED (BUT MOSTLY FAILED) ELEVATED CONVECTIVE INITIATION  
OVER THE PAST FEW HOURS ALONG A LA CROSSE TO GREEN BAY LINE,  
CO-LOCATED WITH THE LEADING EDGE OF THE 925-850MB LLJ.  
 
DESPITE THE APPARENT LACK OF PRECIP ON THE RADAR, WE MAY YET SEE  
SOME SCATTERED DEVELOPMENT OVERHEAD (AS SHOWN ON INTERMEDIATE  
CAM RUNS) BETWEEN NOW AND LATE THIS MORNING, DRIVEN BY MUCAPE  
AND CONTINUED LLJ ACTIVITY. INSTABILITY WITH IT WOULD BE FAIRLY  
LIMITED, ONLY 500 JOULES MUCAPE OR LOCALLY HIGHER. THIS WOULD  
ALLOW FOR SHOWERS WITH BRIEFLY HEAVY RAINFALL AND A FEW RUMBLES  
OF THUNDER, BUT THAT'S JUST ABOUT IT.  
 
DRIER AIR WILL BEGIN TO ADVECT INTO THE REGION BEHIND A COLD  
FRONT MIDDAY, QUICKLY BRINGING AN END TO THE PRECIP CHANCES AND  
GRADUALLY REDUCING CLOUD COVER THROUGH THE AFTERNOON TODAY.  
 
SHEPPARD  
 
 
   
SHORT TERM  
 
ISSUED 129 AM CDT WED SEP 9 2026  
 
TODAY THROUGH THURSDAY NIGHT:  
 
RAIN WITH ISOLATED EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS  
FAR SOUTHERN WISCONSIN, WITH MINIMAL IMPACTS EXPECTED.  
ADDITIONAL STORMS ARE IN THE PROCESS OF DEVELOPING ALONG THE  
NOSE OF THE LLJ IN CENTRAL WISCONSIN, AND ARE EXPECTED TO  
PROGRESS GRADUALLY SOUTHEASTWARD THROUGH SOUTHERN WISCONSIN  
THROUGH THIS MORNING. LIGHTNING IS EXPECTED TO BE THE MAIN  
HAZARD WITH THIS ACTIVITY, BUT HEAVY RAIN IS ALSO POSSIBLE DUE  
TO CONTINUED HIGH PWATS IN THE 1.5 TO 2 INCH RANGE. HOWEVER, ANY  
HEAVY RAIN IMPACTS WOULD BE DEPENDENT ON MULTIPLE STORMS MOVING  
OVER THE SAME AREA. STORMS WILL TAPER OFF INTO THE EARLY MORNING  
HOURS AND BECOME ANOTHER AREA OF LIGHT RAIN AS THE LLJ SHUTS  
OFF. SHOWERS AND RAIN THEN END NORTH TO SOUTH BY MID-MORNING.  
 
HIGH PRESSURE RETURNS TO THE AREA THIS AFTERNOON, BRINGING  
CLEARING SKIES AND NORTHWESTERLY WINDS. EXPECT HIGHS IN THE  
UPPER 70S TO LOW 80S. WINDS GRADUALLY DIMINISH THROUGH THE  
EVENING, WITH MOSTLY CLEAR SKIES AND LIGHT AND VARIABLE WINDS  
OVERNIGHT TONIGHT. EXPECT LOWS IN THE MID 50S TO NEAR 60  
DEGREES.  
 
HIGH PRESSURE PROPAGATES OVERHEAD THURSDAY INTO THURSDAY NIGHT,  
WITH CONTINUED LIGHT AND VARIABLE WINDS, HIGHS IN THE 70S, AND  
LOWS IN THE 50S.  
 
MH  
 
 
   
LONG TERM  
 
ISSUED 129 AM CDT WED SEP 9 2026  
 
FRIDAY THROUGH MONDAY:  
 
FRIDAY AND FRIDAY EVENING WILL BE DRY NOW, AS THE FORECAST HAS  
TRENDED DRIER EACH DAY. THIS IS DUE TO HIGH PRESSURE REMAINING IN  
PLACE OVER THE LOWER GREAT LAKES LONGER. LOW PRESSURE DEVELOPING  
OVER THE DAKOTAS ON FRIDAY WILL LIFT INTO NORTHERN MN. WE CAN  
EXPECT INCREASING SOUTHERLY WINDS IN SOUTHERN WI, ALONG WITH AN  
UPTICK IN TEMPERATURES AND DEWPOINTS (UPPER 70S/LOWER 60S).  
 
THE STRONGEST FORCING WILL BE OVER UPPER MICHIGAN AS THE LOW  
TRACKS OVERHEAD AND THE LOW LEVEL JET FOCUSES THERE. THE OTHER  
AREA OF FORCING WILL ARRIVE WITH A MID LEVEL SHORTWAVE TROUGH  
TRACKING FROM THE CENTRAL PLAINS TO IA AND NORTHERN IL LATE  
FRIDAY NIGHT THROUGH SATURDAY MORNING. THERE ARE HINTS FROM THE  
MODELS THAT THE PRECIP ASSOCIATED WITH THESE TWO FORCING AREAS  
WILL SPLIT RIGHT AROUND SOUTHERN WI.  
 
WINDS WILL SHIFT TO THE WEST SATURDAY AFTERNOON BEHIND THE SURFACE  
TROUGH, BUT GUSTS WILL BE LESS THAN 20 MPH. SATURDAY WILL BE OUR  
WARMEST AND MOST HUMID DAY WITH HIGHS CLOSER TO 80 AND DEWPOINTS  
POTENTIALLY POOLING AHEAD OF THE TROUGH/COLD FRONT TO VALUES IN  
THE UPPER 60S. TEMPERATURES WILL FALL INTO THE 50S SATURDAY NIGHT  
BEHIND THAT FRONT.  
 
A STRONGER MID LEVEL TROUGH CROSSING THE NORTHERN ROCKIES ON  
SUNDAY WILL HELP PUSH THAT FRONT BACK UP THROUGH SOUTHERN WI.  
LIGHT RAIN MAY ACCOMPANY THIS WARM FRONT DURING THE DAY, BUT  
MODELS ARE TRENDING LATER WITH THE STORM CHANCES. THE IMPORTANT  
FEATURE TO NOTE THIS FAR OUT IS THAT THERE WILL BE A PROMINENT  
WARM FRONT WITH THE NOSE OF THE LOW LEVEL JET PRESENT. THIS WILL  
ALIGN WITH THE RIGHT ENTRANCE REGION OF AN UPPER JET AND A LOW-  
AMPLITUDE MID LEVEL SHORTWAVE (WEAK INTENSITY). THE LOCATION OF  
THIS WARM FRONT/LLJ NOSE IS STILL UNCERTAIN. A STORM COMPLEX  
SHOULD DEVELOP ALONG THIS FRONT SUNDAY EVENING AND THERE SHOULD BE  
SUFFICIENT SHEAR AND INSTABILITY FOR SOME SEVERE STORMS, BUT WE  
ARE NOT SURE IF THEY WILL BE EXACTLY IN SOUTHERN WI.  
 
THE SURFACE TROUGH CROSSING WI ON MONDAY AFTERNOON OR NIGHT COULD  
TRIGGER ANOTHER ROUND OF SHOWERS AND STORMS.  
 
CRONCE  
 
 
   
AVIATION  
 
ISSUED 430 AM CDT WED SEP 9 2026  
 
A CHANCE FOR SHOWERS AND EMBEDDED WEAK THUNDERSTORMS TO  
REDEVELOP OVER SOUTHERN WI THIS MORNING, WITH SOME MVFR / FUEL-  
ALT MVFR CLOUD CEILINGS POSSIBLE WITH OR WITHOUT THIS ACTIVITY.  
ALREADY SEEING THE LOW CEILINGS OVER THE SOUTHWEST CORNER AND  
CENTRAL PORTIONS OF THE STATE DESPITE THE CURRENT (AS OF 430 AM)  
LACK OF SHOWERS AND STORMS.  
 
DRY WEATHER AND DECREASING CLOUD COVERAGE EXPECTED FROM MIDDAY  
ONWARDS AS A COLD FRONT ADVECTS DRIER AIR INTO THE REGION. A  
LIGHT SOUTHWEST BREEZE CONTINUES AHEAD OF THE FRONT THIS  
MORNING, VEERING DUE WEST (AND BECOMING BREEZY OVER CENTRAL  
PORTIONS OF THE STATE) BEHIND IT THIS AFTERNOON. SOME 15-20KT  
GUSTS FURTHER NORTH TOWARDS CENTRAL WI. DRY WEATHER AND VFR  
CONTINUE THIS AFTERNOON THROUGH THE REST OF THE TAF PERIOD.  
 
SHEPPARD  
 
 
   
MARINE  
 
ISSUED 129 AM CDT WED SEP 9 2026  
 
LOW PRESSURE AROUND 29.3 INCHES WILL CONTINUE LIFTING NORTHWARD  
THROUGH THE HUDSON BAY TODAY, AS HIGH PRESSURE OF 30.2 INCHES  
BUILDS INTO THE CENTRAL PLAINS. EXPECT SOUTHWESTERLY WINDS TO  
SHIFT TO NORTHWESTERLY THIS MORNING INTO THIS AFTERNOON AS A  
COLD FRONT MOVES SOUTHEASTWARD. THUNDERSTORMS ARE POSSIBLE AHEAD  
OF AND ALONG THIS FRONT. HIGH PRESSURE GRADUALLY MOVES EASTWARD  
INTO THE OHIO VALLEY BY FRIDAY, LEADING TO LIGHT AND VARIABLE  
WINDS ACROSS THE LAKE TONIGHT THROUGH FRIDAY MORNING. WINDS THEN  
BECOME SOUTHERLY AND INCREASE AS LOW PRESSURE DEEPENS IN THE  
CENTRAL PLAINS ONCE AGAIN. ISOLATED GALES ARE POSSIBLE IN THE  
NORTHERN THIRD FRIDAY AFTERNOON INTO FRIDAY NIGHT. LOW PRESSURE  
LIFTS INTO SOUTHERN ONTARIO FRIDAY NIGHT, BRINGING A COLD FRONT  
WITH SHOWERS AND STORMS AND SHIFTING WINDS TO NORTHWESTERLY  
SATURDAY THROUGH SATURDAY NIGHT. ADDITIONAL RAIN AND STORMS ARE  
POSSIBLE SUNDAY INTO MONDAY AS A WARM FRONT FROM ANOTHER  
DEVELOPING LOW PRESSURE SYSTEM LIFTS THROUGH THE REGION.  
 
MH  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...NONE.  
LM...NONE.  
 
 
 
 
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