049  
FXUS63 KMKX 252103  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
403 PM CDT SAT JUL 25 2026  
   
KEY MESSAGES  
 
- THERE IS A MODERATE SWIM RISK AFTERNOON AND EVENING FOR THE  
LAKE MICHIGAN BEACHES IN SHEBOYGAN COUNTY. BREAKING WAVES AND  
CURRENTS ARE EXPECTED. STAY AWAY FROM DANGEROUS AREAS LIKE  
PIERS, BREAKWALLS, AND RIVER OUTLETS.  
 
- HOT AND HUMID CONDITIONS SUNDAY AND MONDAY ARE LIKELY. A HEAT  
ADVISORY IS IN EFFECT FROM NOON TO 9 PM CDT SUNDAY. ADDITIONAL  
HEAT ADVISORIES MAY BE NEEDED MONDAY.  
 
- A LINE OF STORMS MAY IMPACT SOUTHWESTERN WISCONSIN EARLY  
SUNDAY MORNING. AN ISOLATED SEVERE STORM MAY PRODUCE DAMAGING  
WIND WITH THIS ACTIVITY.  
 
- ISOLATED TO SCATTERED STORMS MAY DEVELOP SUNDAY AFTERNOON AND  
EVENING. LARGE HAIL AND DAMAGING WINDS WOULD BE POSSIBLE WITH  
THIS ACTIVITY. SUNDAY NIGHT, A LINE OF STORMS WITH DAMAGING  
WINDS AND HAIL IS EXPECTED TO DEVELOP AND PROGRESS  
SOUTHEASTWARD.  
 
- MONDAY, A COLD FRONT WILL BRING FINAL CHANCES FOR STORMS TO  
SOUTHERN WISCONSIN. ALL HAZARDS ARE POSSIBLE WITH THIS  
ACTIVITY, BUT CONFIDENCE IN EXACT TIMING AND PLACEMENT REMAINS  
DEPENDENT ON SUNDAY NIGHT STORMS.  
 
 
   
SHORT TERM  
 
ISSUED 404 PM CDT SAT JUL 25 2026  
 
TONIGHT THROUGH SUNDAY NIGHT:  
 
WITH LOW STRATUS CONTINUING TO CAP THE ENVIRONMENT, NOT  
EXPECTING ANY STORM DEVELOPMENT THIS AFTERNOON AND EVENING.  
TEMPERATURES WILL CONTINUE TO CLIMB AS SOUTHWESTERLY WINDS BRING  
IN A WARM, MOIST AIRMASS WITH DEWPOINTS IN THE 70S. EXPECT  
CLOUDY CONDITIONS AND HIGHS IN THE LOW 80S.  
 
OVERNIGHT TONIGHT, A COMPLEX OF STORMS MAY DEVELOP (15-25%  
CHANCE) ALONG THE NOSE OF THE 850 MB LLJ IN NORTHERN IOWA,  
PROGRESSING SOUTHEASTWARD INTO SOUTHWESTERN WISCONSIN INTO THE  
EARLY MORNING HOURS SUNDAY. IF THIS COMPLEX DEVELOPS AND  
MAINTAINS INTENSITY, DAMAGING WINDS AND LIGHTNING WOULD BE THE  
MAIN THREATS, PRIMARILY WEST OF THE MADISON METRO. SOME RAIN MAY  
LINGER INTO SUNDAY MORNING, BUT IS NOT EXPECTED TO BE  
IMPACTFUL.  
 
SKIES CLEAR INTO SUNDAY MIDDAY, WITH TEMPERATURES QUICKLY RISING  
TO NEAR 90 DEGREES ACROSS SOUTHERN WISCONSIN UNDER CONTINUED  
SOUTHWESTERLY WINDS. AREAS ALONG LAKE MICHIGAN ITSELF MAY SEE A  
SOUTH-SOUTHEASTERLY LAKE BREEZE, KEEPING TEMPERATURES IN THE  
LOW 80S. HOWEVER, CONFIDENCE IS HIGH IN MOST AREAS SEEING HEAT  
INDEX VALUES OF 100-103 DEGREES, AND A HEAT ADVISORY HAS BEEN  
ISSUED FOR NOON TO 9 PM CDT ON SUNDAY FOR ALL COUNTIES AWAY FROM  
OZAUKEE AND SHEBOYGAN.  
 
SUNDAY AFTERNOON, MESOSCALE MODELING IS INDICATING POTENTIAL FOR  
STORMS TO DEVELOP ALONG THE CONVERGENT ZONE AT THE NORTHERN EDGE  
OF THE UPPER LEVEL RIDGING. THESE STORMS WOULD PROGRESS QUICKLY  
SOUTHWARD THROUGH LAKE MICHIGAN, POTENTIALLY IMPACTING LAKE  
MICHIGAN COUNTIES (30-40% CHANCE) DURING THE EVENING HOURS WITH  
HIGH WINDS, HAIL, AND AN ISOLATED TORNADO POSSIBLE. THESE  
STORMS WILL QUICKLY PROGRESS SOUTHWARD. MEANWHILE, ANY OUTFLOW  
BOUNDARIES FROM THE MAIN COMPLEX MAY PRODUCE ISOLATED TO  
SCATTERED STORMS INLAND ACROSS THE REMAINDER OF SOUTHERN  
WISCONSIN. THESE STORMS WOULD HAVE THE PRIMARY HAZARDS OF HAIL  
AND DAMAGING WINDS, BUT CONFIDENCE IN INLAND DEVELOPMENT IS  
QUITE LOW (15-25%). ENVIRONMENT IS PRIMED (0-6 KM BULK SHEAR ~35  
KT, CAPE 3000-4000 J/KG, PWATS 1.5-1.75 INCH), BUT CAPPING DOES  
REMAIN IN PLACE. IF A STORM CAN DEVELOP THROUGH THE CAP, IT WILL  
BE SEVERE. THE MAIN QUESTION IS TRIGGER.  
 
REGARDLESS OF SUNDAY AFTERNOON AND EVENING DEVELOPMENT,  
EXPECTING LLJ TO NOSE INTO WESTERN WISCONSIN OVERNIGHT SUNDAY,  
BRINGING THE NEXT CHANCES FOR SEVERE DEVELOPMENT TO THE AREA.  
GLOBAL MODELS REMAIN CONSISTENT WITH MCS DEVELOPMENT OVER  
NORTHERN TO CENTRAL WISCONSIN, PROGRESSING SOUTHEASTWARD LATE  
OVERNIGHT SUNDAY INTO MONDAY MORNING. THESE STORMS WOULD BE  
CAPABLE OF PRODUCING DAMAGING WINDS AS THE MAIN THREAT WITH  
PLENTY OF MUCAPE (~2500 J/KG) AND PWATS AROUND 1.75 INCHES  
BECOMING COMMON ACROSS THE REGION. BULK SHEAR REMAINS LOW RIGHT  
AT 30-35 KT, SO TORNADO THREAT LOOKS TO BE MINIMAL. THESE STORMS  
WILL PUSH INTO NORTHERN ILLINOIS INTO MONDAY MORNING.  
 
MH  
 
 
   
LONG TERM  
 
ISSUED 404 PM CDT SAT JUL 25 2026  
 
MONDAY THROUGH SATURDAY:  
 
SHOWERS WITH ISOLATED EMBEDDED LIGHTNING MAY LINGER INTO MONDAY.  
HOW LONG THESE SHOWERS LINGER AND THEREFORE WHERE THE EFFECTIVE  
BOUNDARY SETS UP WILL BE WHAT SETS THE STAGE FOR THE NEXT ROUND  
OF POTENTIAL SEVERE STORMS MONDAY AFTERNOON/EVENING. PROVIDED  
CLOUDS CLEAR EFFICIENTLY INTO THE AFTERNOON HOURS, AN ADDITIONAL  
HEAT ADVISORY MAY BE NEEDED MONDAY AFTERNOON FOR HEAT INDEX  
VALUES IN THE LOW 100S AND TEMPERATURES IN THE UPPER 80S TO LOW  
90S ONCE AGAIN, AS WELL AS ENHANCED HUMIDITY (DEWPOINTS IN THE  
70S ADVECTING IN AS WELL AS ANY ADDITIONAL MOISTURE FROM STORMS  
SUNDAY NIGHT/MONDAY MORNING). DEPENDING ON THE WESTWARD EXTENT  
OF CLOUD COVER, MAY ONLY NEED PORTIONS OF SOUTHWESTERN WISCONSIN  
UNDER A HEAT ADVISORY, AND CONDITIONS WILL CONTINUE TO BE  
EVALUATED AS THE EVENT DRAWS CLOSER.  
 
MONDAY EVENING, A SHORTWAVE EJECTS FROM CANADA, RIDING OVER THE  
RIDGING THAT REMAINS ACROSS THE UPPER MIDWEST AND ATTACHING  
ITSELF TO ANY BOUNDARY LINGERING FROM THE MORNING CONVECTION.  
EXPECTING CAPE VALUES TO RECOVER QUICKLY INTO THE 2000 TO 3000  
J/KG RANGE AFTER CLOUD COVER EXITS, AND FOR SHEAR TO INCREASE TO  
40-45 KT AHEAD OF THE SHORTWAVE/EFFECTIVE COLD FRONT. SEVERE  
STORMS ONCE AGAIN BECOME POSSIBLE AS THE SHORTWAVE MOVES THROUGH  
THE REGION, BUT WILL DEPEND LARGELY ON PRECURSORY CONDITIONS.  
THEREFORE, CONFIDENCE IS RISING IN TIMING, BUT IMPACTS REMAIN IN  
QUESTION.  
 
MONDAY NIGHT, STORMS FINALLY EXIT TO THE EAST AND NORTHWESTERLY  
WINDS DEVELOP, BRINGING IN COOLER AND DRIER AIR WITH LOWS IN THE  
MID 60S. TUESDAY, EXPECT NORTHERLY WINDS TO CONTINUE AS HIGH  
PRESSURE BUILDS IN, CONTINUING TO REDUCE THE HUMIDITY BUT  
KEEPING HIGHS IN THE MID-80S AWAY FROM LAKE MICHIGAN (LAKE  
BREEZE INFLUENCE). DRY CONDITIONS UNDER HIGH PRESSURE LINGER  
THROUGH AT LEAST WEDNESDAY, BUT HIGH PRESSURE BEGINS TO BREAK  
DOWN THURSDAY NIGHT INTO FRIDAY AHEAD OF LOW PRESSURE EJECTING  
FROM THE NORTHERN PLAINS.  
 
NEXT CHANCES FOR STORMS DEVELOP THURSDAY NIGHT THROUGH FRIDAY  
AS WARM FRONTOGENESIS BUILDS ACROSS THE UPPER MIDWEST AND LOW  
PRESSURE MAKES ITS CLOSEST APPROACH. PRECIPITATION CHANCES  
DIMINISH INTO NEXT WEEKEND AS HIGH PRESSURE CENTERED OVER  
NORTHERN ONTARIO BEGINS TO BUILD BACK SOUTHWARD.  
 
MH  
 
 
   
AVIATION  
 
ISSUED 404 PM CDT SAT JUL 25 2026  
 
CEILINGS IN THE 1500-2500 FT RANGE WILL SLOWLY SCATTER OUT INTO  
THIS EVENING, WITH CONDITIONS RETURNING TO VFR TONIGHT. PATCHY  
FOG WILL DEVELOP IN SOUTHWESTERN TO SOUTH-CENTRAL WISCONSIN  
LATE TONIGHT, BRINGING VISIBILITIES DOWN TO MVFR FOR JVL AND  
MSN THROUGH SUNRISE. AN ISOLATED STORM IS POSSIBLE FOR  
SOUTHWESTERN WISCONSIN TONIGHT, BUT CURRENTLY IS EXPECTED TO  
REMAIN WEST OF MSN. SUNDAY, VFR CONDITIONS ARE EXPECTED TO  
DOMINATE. DURING THE AFTERNOON TO EVENING HOURS, A LINE OF  
STORMS MAY MOVE SOUTHWARD ALONG LAKE MICHIGAN WITH DAMAGING  
WINDS AND AN ISOLATED TORNADO. CURRENTLY A 20-30% CHANCE OF  
SEEING THESE STORMS PROGRESS INLAND. ISOLATED STORMS (15-20%  
CHANCE) ARE POSSIBLE DURING THE AFTERNOON INLAND OF THE LINE,  
BUT ARE EXPECTED TO BE TRANSIENT.  
 
MH  
 
 
   
MARINE  
 
ISSUED 404 PM CDT SAT JUL 25 2026  
 
A WEAK LOW PRESSURE TROUGH AROUND 29.8 INCHES WILL STALL ALONG THE  
WISCONSIN-UPPER MICHIGAN BORDER THIS EVENING. IT WILL REMAIN OVER  
WISCONSIN AND LAKE MICHIGAN THROUGH MOST OF MONDAY WHICH WILL  
RESULT IN INCREASING THUNDERSTORM CHANCES WITH SEVERE STORMS  
POSSIBLE. VERY WARM, MOIST AND UNSTABLE AIR FLOWING OVER THE  
RELATIVELY COOL WATERS MAY CAUSE PATCHY DENSE FOG OVER THE LAKE  
THROUGH MONDAY AS WELL.  
 
NORTHERLY WINDS WILL DEVELOP MONDAY NIGHT THROUGH WEDNESDAY AS  
HIGH PRESSURE AROUND 29.9 INCHES BUILDS OVER THE UPPER GREAT LAKES  
AND THE FRONT PUSHES SOUTHWARD. A FEW GALE FORCE GUSTS ARE  
POSSIBLE TUESDAY AFTERNOON. LOOK FOR SOUTHERLY WINDS AND MORE  
UNSETTLED WEATHER TO RESUME THURSDAY INTO NEXT WEEKEND.  
 
CRONCE  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...HEAT ADVISORY...WIZ046-WIZ047-WIZ051-WIZ056-WIZ057-WIZ058-  
WIZ059-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-WIZ067-WIZ068-  
WIZ069-WIZ070-WIZ071-WIZ072...NOON SUNDAY TO 9 PM SUNDAY.  
 
LM...NONE.  
 
 
 
 
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