366  
FXUS63 KMKX 051145  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
645 AM CDT SAT SEP 5 2026  
   
KEY MESSAGES
 
 
- PATCHY DENSE FOG ACROSS SOUTHERN WI EARLY THIS MORNING,  
ESPECIALLY IN WESTERN DANE COUNTY AND THE BARABOO / WISCONSIN  
RIVER VALLEYS.  
 
- MILDER TEMPS AND DRIER, LESS HUMID CONDITIONS THIS WEEKEND AND  
LABOR DAY WITH DAYTIME HIGHS IN THE 70S AND LOW 80S AND  
NIGHTLY TEMPS FALLING INTO THE UPPER 50S TO LOW 60S.  
 
- WARMER TEMPS AND HUMIDITY RETURN TUESDAY AND WEDNESDAY WITH  
THE NEXT CHANCES FOR SHOWER AND THUNDERSTORMS.  
 

 
   
UPDATE
 
 
ISSUED 645 AM CDT SAT SEP 5 2026  
 
DOT CAMERAS AND SURFACE OBSERVING NETWORKS REVEAL SOME PATCHY  
DENSE FOG ACROSS THE WESTERN MSN BELTLINE AND THE BARABOO / WI  
RIVER VALLEYS. A FEW OTHER POCKETS OF FOG ACROSS THE REST OF  
SOUTHERN WI, ESPECIALLY IN LOW-LYING MARSHY AREAS (SEVERAL  
AIRPORT OBSERVING SITES), HIGHER ELEVATION AREAS (INTERSECTING  
THE < 300-600 FT OVERCAST CLOUD CEILINGS), AND THE IMMEDIATE  
SHORELINE OF LAKE MI. EXPECTING THE FOG AND LOW CLOUD CEILINGS  
TO SLOWLY LIFT OVER THE COURSE OF THE NEXT FEW HOURS, REMAINING  
MOSTLY CLOUDY UNTIL MID-AFTERNOON.  
 
THE HOLIDAY WEEKEND FORECAST REMAINS ON TRACK. DRY AND QUIET  
WEATHER WITH LINGERING HUMIDITY TODAY (DEWPOINTS AROUND 70)  
FOLLOWED BY SLIGHTLY LESS HUMID CONDITIONS SUNDAY INTO MONDAY.  
 
SHEPPARD  
 

 
   
SHORT TERM
 
 
ISSUED 1201 AM CDT SAT SEP 5 2026  
 
TODAY THROUGH SUNDAY NIGHT:  
 
OUTSIDE OF AN ISOLATED POP-UP SHOWER TOWARD THE WI/IL BORDER,  
MOSTLY DRY INTO THE MORNING. OTHERWISE, WE CONTINUE TO SEE A  
WEAK COLD FRONT CONTINUE PUSH ITS WAY SOUTHWARD THROUGH THE  
MORNING ENHANCED BY THE EASTERLY FLOW FROM HIGH PRESSURE. LIGHT  
WINDS AND ELEVATED SURFACE MOISTURE FROM RECENT RAINFALL BEHIND  
THE FRONT WILL SET THE STAGE FOR FOG DEVELOPMENT ACROSS THE AREA  
THROUGH THE MORNING. EXPECT PRETTY WIDESPREAD COVERAGE WITH  
VISIBILITIES OF 1-3SM, BUT ALSO COULD SEE POCKETS OF DENSE FOG  
AT TIMES, ESPECIALLY FOR LOW-LYING AREAS AND RIVER VALLEYS. DO  
NOT KNOW IF AND HOW WIDESPREAD THE DENSE FOG MAY GET, BUT WILL  
CONTINUE TO MONITOR AND SEE IF A ADVISORY MAY BE WARRANTED.  
NONETHELESS, THE FOG IS EXPECTED TO CONTINUE THROUGH THE  
MORNING, BUT GRADUALLY LIFT BY MID TO LATE MORNING WITH SOME  
LOWER CLOUDS LAGGING BEHIND BY AN HOUR OR TWO.  
 
EXPECT DRIER, NOT AS HUMID, AND MILDER CONDITIONS BY THIS AFTERNOON  
AS UPPER-LEVEL RIDGE BEGINS TO BUILD ACROSS THE UPPER MIDWEST. THIS  
WILL ALLOW LIGHT EASTERLY FLOW OFF OF LAKE MICHIGAN TO BECOME MORE  
PREVALENT ACROSS SOUTHERN WI AS HIGH PRESSURE BUILDS INTO THE GREAT  
LAKES REGION FROM CANADA THROUGH THE AFTERNOON AND EVENING. AS A  
RESULT TEMPS IN THE UPPER 70S TOWARD THE LAKE AND TO LOWER 80S  
INLAND TOWARD SOUTHWESTERN WI EXPECTED THIS AFTERNOON. COOLER  
CONDITIONS ARE EXPECTED OVERNIGHT WITH LOWS DIPPING INTO THE UPPER  
50S TO LOW 60S.  
 
THIS HIGH PRESSURE AND DRIER PATTERN WILL REMAIN IN PLACE THROUGH  
THE REMAINDER OF THE HOLIDAY WEEKEND WITH SIMILAR TEMPS  
AND DRIER CONDITIONS FOR SUNDAY ALONG WITH LESS HUMIDITY.  
 
WAGNER  
 

 
   
LONG TERM
 
 
ISSUED 1201 AM CDT SAT SEP 5 2026  
 
MONDAY THROUGH FRIDAY:  
 
INFLUENCE FROM THE UPPER-LEVEL RIDGE AND SURFACE HIGH PRESSURE  
OVER THE GREAT LAKES WILL CONTINUE TROUGH THE HOLIDAY AS IT WILL  
BE REINFORCED BY AN ADDITIONAL AREA OF HIGH PRESSURE BUILDING  
DOWN. PREDOMINATELY EASTERLY FLOW OFF OF LAKE MICHIGAN WILL HELP  
KEEP A COUPLE OF DEGREE COOLER THAN WHAT WE HAVE BEEN SEEING  
ALONG WITH LESS HUMIDITY. HIGHS FOR LABOR DAY ARE LOOKING TO TOP  
OFF IN THE UPPER 70S TO LOW 80S.  
 
THEN INFLUENCE FROM THE HIGH PRESSURE WANES INTO TUESDAY AS THE  
UPPER-LEVEL RIDGE AXIS SLIDES EASTWARD WHILE AND UPPER-LEVEL  
TROUGH LIFTS ACROSS THE UPPER MIDWEST. THIS PATTERN SHIFT IS  
EXPECTED TO BRING MORE SOUTHERLY FLOW TO SOUTHERN WI ALONG WITH  
LOW-LEVEL WAA, MOISTURE ADVECTION, AND TEMPS WARMING BACK INTO  
THE 80S FOR TUESDAY INTO WEDNESDAY. THIS WILL ALSO BE THE NEXT  
WINDOW FOR INCREASED SHOWER AND STORM CHANCES ACROSS THE AREA AS  
IT BRINGS A SURFACE LOW ACROSS MANITOBA/ONTARIO WITH A COLD  
FRONT DRIFTING ACROSS THE UPPER MIDWEST LATER TUESDAY INTO  
WEDNESDAY. HOWEVER, THE BETTER UPPER- LEVEL DYNAMICS LOOK TO  
REMAIN TO THE NORTH CLOSER TIED TO THE TROUGH/LOW ITSELF, THE  
LOW-LEVEL FORCING FROM THE FRONT ALONG WITH SOME WAA AND SIGNS  
OF A LLJ ARE LOOKING TO BE ENOUGH FOR THE INCREASED POP CHANCES  
LATER TUESDAY INTO WEDNESDAY.  
 
THEN BEHIND THE MIDWEEK SYSTEM, THE PATTERN IS TRENDING MORE  
BENIGN WITH ZONAL UPPER-LEVEL FLOW AND HIGH PRESSURE BUILDING  
ACROSS THE REGION FOR THE END OF THE WEEK.  
 
WAGNER  
 

 
   
AVIATION
 
 
ISSUED 630 AM CDT SAT SEP 5 2026  
 
OVERCAST LOW CLOUD CEILINGS AND PATCHY DENSE FOG ARE LEADING TO  
WIDESPREAD LIFR CONDITIONS EARLY THIS MORNING. EXPECTING THESE  
CEILINGS TO SLOWLY LIFT TO IFR / FUEL-ALT MVFR LEVELS LATER THIS  
MORNING AND SCATTER APART TO VFR THROUGH THIS AFTERNOON. SKIES  
THEN REMAIN MOSTLY CLEAR THROUGH THE REST OF THE TAF PERIOD AS  
HIGH PRESSURE BUILDS INTO THE REGION. NORTHEAST WINDS AT 5 TO  
10 KNOTS TODAY, LIGHT AND VARIABLE LATE TONIGHT, THEN LIGHT  
EASTERLY WINDS FOR SUNDAY. DRY WEATHER EXPECTED THROUGH THE TAF  
PERIOD AND THE REST OF THE HOLIDAY WEEKEND.  
 
SHEPPARD  
 

 
   
MARINE
 
 
ISSUED 1201 AM CDT SAT SEP 5 2026  
 
LIGHT WINDS OVER LAKE MICHIGAN WILL SHIFT EAST-NORTHEASTERLY  
OVERNIGHT INTO SATURDAY MORNING A COLD FRONT GRADUALLY SLIDES  
SOUTHWARD. AREAS OF DENSE FOG MAY FORM OVER CENTRAL AND  
SOUTHERN LAKE MICHIGAN AFTER THE FRONTAL PASSAGE AND CONTINUE  
THROUGH SATURDAY MORNING. THEN HIGH PRESSURE BUILDS OVER THE  
GREAT LAKES FROM ONTARIO THROUGH THE WEEKEND AND WILL BRING  
MODEST NORTHEAST WINDS THROUGH SATURDAY, ESPECIALLY FOR CENTRAL  
AND SOUTHERN LAKE MICHIGAN. WINDS EVENTUALLY WEAKEN AND BECOME  
MORE LIGHT AND VARIABLE FOR SUNDAY AND MONDAY AS AN ADDITIONAL  
HIGH PRESSURE SLOWLY REINFORCES THE HIGH PRESSURE OVER THE GREAT  
LAKES.  
 
WAGNER  
 

 
   
MKX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
LM...NONE.  

 
 

 
 
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