545  
FXUS63 KMKX 030021  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
721 PM CDT WED SEP 2 2026  
   
KEY MESSAGES  
 
- UNSEASONABLY WARM AND MUGGY CONDITIONS CONTINUE THROUGH THE  
END OF THE WORK WEEK. UPPER 90S TO NEAR 100 DEGREE HEAT  
INDICES WILL BE POSSIBLE DAILY IN AREAS EXPERIENCING AMPLE  
SUNSHINE, ESPECIALLY TODAY.  
 
- OCCASIONAL STORM CHANCES CONTINUE INTO THE BEGINNING OF THE  
WEEKEND, WITH PLENTY OF DRY PERIODS IN BETWEEN. SOME STORMS  
COULD BE ON THE STRONGER SIDE.  
 
 
   
UPDATE  
 
ISSUED 715 PM CDT WED SEP 2 2026  
 
FORECAST REMAINS ON TRACK WITH UNSEASONABLE MUGGY CONDITIONS. A  
FEW ISOLATED SPRINKLES REMAIN POSSIBLE SOUTH OF I-94 THROUGH  
SUNSET AS THERE IS A LACK OF FORCING TO GET ANYTHING GOING.  
HOWEVER, THE NOSE OF 30-35 KT LLJ IS PROGGED TO PUSH IN THIS  
OVERNIGHT AFTER 06Z AND IS SHAPING UP TO BE THE FOCUS FOR  
ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT THROUGH  
DAYBREAK. DEPENDING ON THIS OVERNIGHT/EARLY MORNING ACTIVITY  
WILL THEN SET THE STAGE OR LIMIT ADDITIONAL DEVELOP FOR  
THURSDAY.  
 
WAGNER  
 
 
   
SHORT TERM  
 
ISSUED 1144 AM CDT WED SEP 2 2026  
 
TONIGHT THROUGH THURSDAY NIGHT:  
 
THE HOT AND HUMID CONDITIONS CONTINUE ACROSS SOUTHERN WISCONSIN. A  
STATIONARY FRONT IS ROUGHLY ALONG I-94 THIS AFTERNOON WHICH WILL  
RESULT IN SLIGHTLY COOLER CONDITIONS FOR AREAS NORTH OF THE  
INTERSTATE. THESE SLIGHTLY "COOLER" CONDITIONS ARE THE RESULT OF  
LOWER DEWPOINT VALUES MORE THAN ANYTHING WHICH MAKES THE FEELS LIKE  
TEMPERATURES MORE BEARABLE IN COMPARISON TO AREAS FURTHER  
SOUTH. THE RESULT IS DEWPOINTS IN THE LOW TO MID 60S NEAR  
CENTRAL WISCONSIN WITH DEWPOINTS IN THE LOW 70S ACROSS FAR  
SOUTHERN WISCONSIN. THIS MEANS THAT THE AREAS ON THE BORDER LINE  
OF A HEAT ADVISORY ARE THOSE WI/IL BORDER COUNTIES. TODAY AS  
ALREADY BEEN A MORE BEARABLE DAY IN COMPARISON TO YESTERDAY  
WITH DEWPOINTS WELL BELOW THE UPPER 70S TO LOW 80S OF YESTERDAY  
AFTERNOON. THIS SHOULD KEEP CONDITIONS BELOW THE APPARENT  
TEMPERATURES OF 100 AND AWAY FROM HEAT HEADLINES FOR TODAY.  
THROUGH THE REST OF THE WORK WEEK HEAT INDEX VALUES IN THE 90S  
ARE EXPECTED, BUT THERE IS UNCERTAINTY ON IF WE WILL BE WARM  
ENOUGH TO REACH 100. ANY RAIN/STORMS OR CLOUD COVER COULD IMPACT  
TEMPERATURES JUST ENOUGH TO SWAY VALUES A FEW DEGREES.  
 
GIVEN THE HOT AND HUMID ENVIRONMENT, SOUTHERN WISCONSIN IS PRIMED  
FOR STORMS SHOULD WE GET ANY FORCING OR LIFT. THE MID LEVEL WAA IS  
VERY STRONG WHICH IS RESULTING IN A STRONG CAPPING TODAY AND  
THURSDAY. THIS WILL MAKE IT DIFFICULT FOR ANY STORMS TO BECOME SFC  
BASED. THERE IS A FRONTAL BOUNDARY DRAPED ACROSS SOUTHERN  
WISCONSIN THIS AFTERNOON THAT WILL LINGER IN THE AREA THROUGH  
THURSDAY. THIS WILL PROVIDE SOME WEAK FORCING FOR RAIN AND  
THUNDERSTORM DEVELOPMENT. FOR THIS AFTERNOON, THERE IS A  
NOTICEABLE LACK OF LIFT AND SYNOPTIC SUPPORT ALOFT. SO ITS  
UNLIKELY THAT WE WILL GET ANY RAIN/STORMS UNTIL THIS  
EVENING/TONIGHT.  
 
FOR THURSDAY, THERE WILL BE A SHORTWAVE TROUGH ALOFT WHICH WILL HELP  
PROVIDE LIFT FOR THE CWA. THE LLJ DURING THE OVERNIGHT INTO EARLY  
MORNING HOURS WILL ALSO PROVIDE SOME FORCING. MESO GUIDANCE SUGGESTS  
THAT THE RAIN AND STORMS WILL LIKELY FOLLOW A SIMILAR PATH TO  
THE PREVIOUS NIGHT WHERE STORMS STAY ATTACHED TO THE LLJ WHICH  
FOCUSES ACROSS CENTRAL WISCONSIN. UNLESS AN OUTFLOW STARTS TO  
MOVE THROUGH ITS HARD TO SEE ANY RAIN OR STORMS WORKING THROUGH  
THE CENTER OF THE CWA (LOW CHANCES 10-15% BUT NOT IMPOSSIBLE).  
ACROSS SOUTH CENTRAL WISCONSIN PRECIPITATION CHANCES JUMP TO  
40-60% UNDER THE MORE FAVORABLE SUPPORT. GIVEN THE HIGH PWATS  
AND MOISTURE AS WELL AS THE 30-40KT WIND SHEAR. ORGANIZED  
CONVECTION IS NOT OUT OF THE QUESTION WITH THE EARLY MORNING  
ROUND. ITS LIKELY THAT THE MAIN THREATS WILL BE WIND WITH THE  
WATER LOADING.  
 
FOR THURSDAY EVENING/NIGHT, THERE WILL BE ADDITIONAL CHANCES FOR  
RAIN WITH ANOTHER MID TO UPPER LEVEL SHORTWAVE. THE DIURNAL  
INSTABILITY FOR THE DAY TIME AND THE PRESENCE OF A THAT  
AFOREMENTIONED FRONTAL BOUNDARY SAGGING SOUTH TOWARD THE STATE  
BOARDER SHOULD ALL BE MORE THAN ENOUGH FOR STORM INITIATION. RAIN  
AND STORMS CHANCES IN THE EVENING WILL BE LOW AROUND 10-30% UNTIL  
THE FRONTAL BOUNDARY STARTS TO MOVE SOUTH. THEN PRECIPITATION  
CHANCES JUMP TO 40-60%. AGAIN WITH SHEAR AROUND 40 KTS, THERE WILL  
BE A POTENTIAL FOR ORGANIZED CONVECTION. STRONG WINDS WILL AGAIN BE  
THE MAIN THREAT, BUT CAN'T RULE OUT SOME SMALL HAIL. OVERALL FOR  
THURSDAY THE EARLY MORNING HOURS AND OVERNIGHT HOURS WILL BE THE  
TIMES TO KEEP AN EYE ON FOR RAIN/STORMS.  
 
PATTERSON  
 
 
   
LONG TERM  
 
ISSUED 1144 AM CDT WED SEP 2 2026  
 
FRIDAY THROUGH WEDNESDAY:  
 
THE WARM AND UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS  
SOUTHERN WISCONSIN THROUGH THE EXTENDED. WITH AN UPPER LEVEL HIGH  
CENTERED OVER THE SOUTHERN CONUS, SOUTH TO SOUTHWEST WINDS STRAIGHT  
OUT OF THE GULF WILL REMAIN THROUGH THE EXTENDED. THEREFORE,  
TEMPERATURES IN THE 80S AND DEWPOINTS IN THE UPPER 60S TO 70S ARE  
LIKELY TO CONTINUE. WITH THAT THE HIGH HEAT INDEX IS LIKELY TO  
PERSIST AS WELL. WITH THE SUSTAINED SOUTHWESTERLY FLOW, THERE WILL  
BE ENOUGH WARM AIR AND MOISTURE FOR STORMS AT ANY GIVEN TIME THROUGH  
THE EXTENDED. FOR FRIDAY, THERE WILL BE THE COMBINATION OF THE LLJ  
DURING THE OVERNIGHT HOURS WITH A LINGERING SFC BOUNDARY FOR DAY  
TIME DEVELOPMENT. SIMILAR TO WHAT WE ARE SEEING EARLIER IN THE WEEK.  
 
ONCE WE GET INTO THE WEEKEND THE DIURNAL INSTABILITY REMAINS, BUT  
THERE IS A NOTICEABLE LACK OF SFC FORCING. THE LLJ SHIFTS NORTH AND  
WEST WHILE THE SFC FRONTAL BOUNDARY SAGS TO THE SOUTH.  
THIS WILL LEAD TO MORE DISORGANIZED RAIN AND STORMS CHANCES. SHEAR  
LOOKS TO WEAKEN AS WELL DURING THIS TIME WHICH IN TURN LIMITS THE  
POTENTIAL FOR AN PESKY ISOLATED STRONGER STORMS. REALISTICALLY IT  
SHOULD CLOSE THE DOOR ON IT, BUT IF THERE IS ENOUGH DIURNALLY DRIVEN  
INSTABILITY THEN WE DON'T WANT TO COUNT OUT ANY SINGLE CELL POP UP  
THUNDERSTORM JUST YET. A THUNDERSTORM THAT GETS TALL ENOUGH OR WATER  
LOGGED ENOUGH CAN ALWAYS CAUSE SOME DOWNBURST TYPE WINDS. BUT THAT  
SHOULD BE VERY FEW AND FAR BETWEEN, MORE AN EXCEPTION THAT A RULE IN  
THE ENVIRONMENT WE SHOULD HAVE.  
 
FURTHER AHEAD FOR EARLY NEXT WEEK THERE IS A SIGNAL FOR THE RIDGE  
ALOFT TO WEAKEN A BIT. MEANWHILE A LOW PRESSURE SYSTEM MOVING ACROSS  
CANADA LOOKS TO POTENTIALLY CLIP THE GREAT LAKES REGION. FROM THE  
GLOBAL DETERMINISTIC MODELS, THE GFS LOOKS TO BE THE FURTHER SOUTH  
WITH THE LOW PRESSURE SYSTEM AND TRIES TO UNDERCUT THE HIGH, WHILE  
THE EURO AND CAN KEEP THE LOW FURTHER NORTH. THIS SPLIT IN TRACK  
CONTINUES WHEN LOOKING AT THE CLUSTER ANALYSIS AND ENSEMBLES.  
REGARDLESS OF TRACK A COLD FRONT LOOKS TO MOVE ACROSS THE STATE WITH  
THIS ASSOCIATED LOW. SO THIS COMES DOWN TO A TIMING AND STRENGTH OF  
THE FRONT QUESTION AS WELL. OVERALL JUST SOMETHING TO KEEP AN EYE ON  
AS WE HEAD INTO THE WEEKEND.  
 
PATTERSON  
 
 
   
AVIATION  
 
ISSUED 715 PM CDT WED SEP 2 2026  
 
VFR CONDITIONS WILL MAINLY PREVAIL FOR INLAND AREAS TONIGHT.  
HOWEVER, MODELS DO HINT AT THE ELEVATED LOW-LEVEL MOISTURE AND  
LIGHT WINDS ALONG THE LAKESHORE, ESPECIALLY NORTH OF PORT  
WASHINGTON MAY RESULT IN SOME LOW STRATUS TO DEVELOP BRING IFR  
TO LIFR CEILINGS AND MAYBE EVEN A DROP OF VISIBILITY MAINLY FOR  
SBM. OTHERWISE, COULD SEE SOME SCATTERED SHOWERS AND STORMS  
DEVELOP ALONG THE NOSE OF AN INCOMING LLJ OVERNIGHT THROUGH  
DAYBREAK. IF THIS ACTIVITY PANS OUT, THEN TERMINALS FROM MSN TO  
MKE ARE LIKELY TO SEE IMPACTS FROM THIS ROUND, WHILE ENW AND JVL  
MAY STAY MOSTLY DRY THROUGH THE MORNING. THEN ADDITIONAL SHOWER  
AND THUNDERSTORM CHANCES WILL BE POSSIBLE ACROSS SOUTHERN WI  
THROUGH THE DAY THURSDAY AS THESE HUMID CONDITIONS CONTINUE.  
TIMING AND COVERAGE WILL DEPEND ON THE DEPARTURE OF THE  
OVERNIGHT ROUND AND WHERE THE STALLED BOUNDARY ENDS UP. WITH ANY  
SHOWER AND THUNDERSTORM ACTIVITY EXPECT PERIODS OF LOWER  
CEILINGS AND VISIBILITES. OTHERWISE, LIGHT AND VARYING WINDS  
EXPECTED THURSDAY.  
 
WAGNER  
 
 
   
MARINE  
 
ISSUED 1144 AM CDT WED SEP 2 2026  
 
A STATIONARY FRONT WILL REMAIN ACROSS THE GREAT LAKES REGION THROUGH  
FRIDAY. AS THIS FRONTAL BOUNDARY WAFFLES NORTH TO SOUTH ACROSS THE  
LAKE FROM DAY TO DAY, LIGHT AND VARIABLE WINDS ARE EXPECTED ACROSS  
THE LAKE. GENERALLY EAST TO NORTHEAST WINDS ARE EXPECTED NORTH OF  
THE FRONT WITH EAST TO SOUTHEAST WINDS SOUTH OF THE FRONT. ON AND  
OFF THUNDERSTORMS WILL BE POSSIBLE ALONG AND NORTH OF THIS FRONTAL  
BOUNDARY THROUGH AT LEAST FRIDAY NIGHT.  
 
HEADING INTO SATURDAY HIGH PRESSURE AROUND 30.1 INCHES BUILDS OVER  
THE HUDSON BAY AND BROAD, WHILE A LOW PRESSURE OF 29.6 INCHES MOVES  
INTO THE NORTHERN GREAT PLAINS. SIMILAR TO EARLIER WEEK STORMS,  
WIDESPREAD SEVERE WEATHER ISN'T ANTICIPATED, THOUGH ISOLATED  
STRONGER STORMS WITH HAIL AND GUSTY WINDS ARE POSSIBLE.  
 
PATTERSON  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...NONE.  
LM...NONE.  
 
 
 
 
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