866  
FXUS63 KMKX 191656 AAA  
AFDMKX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
1156 AM CDT TUE MAY 19 2026  
   
KEY MESSAGES
 
 
- DIMINISHING CHANCE FOR SHOWERS WITH THE COLD FRONTAL PASSAGE  
TODAY.  
 
- COOL AND DRIER WEATHER THEN RETURNS FOR MIDWEEK.  
 
- RAIN CHANCES RETURN FRIDAY INTO FRIDAY NIGHT(40-60%),  
FOLLOWED BY A GRADUAL WARMING TREND SATURDAY INTO EARLY NEXT  
WEEK.  
 

 
   
UPDATE
 
 
ISSUED 1156 AM CDT TUE MAY 19 2026  
 
THE COLD FRONT IS APPARENT ON RADAR AND IS TREKKING THROUGH  
SOUTH CENTRAL WI RIGHT NOW. IT IS ALMOST TO MADISON. SPRINKLES  
OR A LIGHT SHOWER ARE POSSIBLE ALONG THE FRONT. THEN EXPECT A  
WIND SHIFT TO THE WEST-NORTHWEST BEHIND THE FRONT, WITH GUSTS UP  
TO 25 MPH (NOT A LOT DIFFERENT THAN THE GUSTS GOING ON RIGHT  
NOW). THERE ARE PLENTY OF CLOUDS UPSTREAM DUE TO THE DIURNAL  
INFLUENCE, SO EXPECT THESE TO THIN OUT OVERNIGHT. LOWS WILL BE  
IN THE LOWER-MID 40S TONIGHT.  
 
CRONCE  
 

 
   
SHORT TERM
 
 
ISSUED 1134 PM CDT MON MAY 18 2026  
 
TONIGHT THROUGH THURSDAY NIGHT:  
 
THE DECAYING MCS IS NOW MOVING INTO SW WI AND WILL CONTINUE TO  
ENCOUNTER MUCH GREATER MLCIN AND HIGH LFCS. HOWEVER, STILL  
EXPECT FAIRLY WIDESPREAD SHOWERS AND SCT STORMS TO MOVE ACROSS  
ALL OF SRN WI DURING THE EARLY MORNING HOURS AS A SSWLY LOW  
LEVEL JET OF 40 KTS INCREASES WARM, MOIST ADVECTION AND BOOSTS  
ELEVATED CAPE TO 1000-2000 J/KG. WIND GUSTS AND SMALL HAIL WILL  
BE THE MAIN CONCERNS.  
 
A WAVE OF LOW PRESSURE ALONG THE STATIONARY FRONT FROM CENTRAL  
IA TO ERN MN WILL TRACK NEWD TO NEAR LAKE SUPERIOR BY 12Z TUE.  
THE LOW WILL THEN TRACK EWD INTO QUEBEC DURING THE DAY WITH ITS  
TRAILING COLD FRONT MOVING ACROSS SRN WI TUE AM INTO THE EARLY  
AFTERNOON. MOIST LOW LEVELS AND MARGINAL INSTABILITY COULD  
RESULT IN A BROKEN LINE OF SHOWERS AND ISOLD STORMS ALONG THE  
FRONT BUT NO SEVERE WX IS ANTICIPATED.  
 
NWLY WINDS AND COLD ADVECTION WILL CONTINUE INTO TUE NT WITH LOW  
TEMPS FALLING INTO THE LOWER TO MIDDLE 40S. HIGH PRESSURE WILL  
THEN MOVE FROM MN TO THE NRN GREAT LAKES ON WED AND REMAIN THERE  
INTO THU. NELY SFC WINDS AND A RELATIVELY COOL AIR MASS WILL  
RESIDE OVER SRN WI WITH HIGH TEMPS IN THE 50S OVER ERN WI AND  
LOWER 60S OVER SOUTH CENTRAL WI. A RETURN OF WARM ADVECTION WILL  
BRING 20 PERCENT CHANCES FOR SHOWERS WEST OF MADISON THU NT.  
 
GEHRING  
 

 
   
LONG TERM
 
 
ISSUED 1134 PM CDT MON MAY 18 2026  
 
FRIDAY THROUGH MONDAY:  
 
LOW PRESSURE EJECTS FROM THE SOUTHERN PLAINS ON FRIDAY, WITH  
CONTINUED MODEL DISCREPANCIES AS TO ITS PROGRESSION. CANADIAN AND  
EURO INDICATE A MORE SOUTHERLY TRACK OF A SINGLE LOW PRESSURE  
SYSTEM BRINGING WIDESPREAD RAIN AND STORMS TO SOUTHERN WISCONSIN  
THROUGHOUT THE DAY ALONG THE NORTHERN SIDE OF THE LOW, WHILE THE  
GFS PREFERS A SPLIT PATTERN WITH ONE PORTION OF THE ENERGY  
PROGRESSING THROUGH THE LOWER MISSISSIPPI VALLEY AND THE OTHER  
FOLLOWING THE JET STREAM INTO MINNESOTA AND BRINGS A WARM FRONT  
WITH RAIN AND STORMS INTO SOUTHERN WISCONSIN. REGARDLESS OF  
SOLUTION, PROBABILITIES OF SEEING RAINFALL HAVE INCREASED, SO KEPT  
LIKELY POPS (50-65%) IN THE FORECAST FOR FRIDAY AFTERNOON INTO  
FRIDAY NIGHT. MODELS ALSO ARE INCLINED TO AGREE THAT PRECIPITATION  
WILL TAPER OFF INTO SATURDAY AS THE WARM FRONT LIFTS NORTH OR THE  
LOW PRESSURE SYSTEM EXITS TO THE EAST. GENERALLY UNSETTLED WEATHER  
LOOKS TO DEVELOP SUNDAY THROUGH TUESDAY AS BROAD 500 MB TROUGHING  
DEVELOPS ACROSS THE UPPER MIDWEST, BRINGING MULTIPLE SHORTWAVES  
THROUGH THE REGION. AS THE UPPER LEVEL TROUGHING DEVELOPS, HIGH  
PRESSURE BUILDING IN THE PLAINS WILL BRING INCREASING TEMPERATURES  
THROUGH THE WEEKEND INTO EARLY NEXT WEEK. MONDAY AND TUESDAY  
TEMPERATURES COULD RETURN TO THE MID-80S. HOWEVER, WEAK, GENERALLY  
SOUTHEASTERLY WINDS WILL ALLOW FOR LAKE MICHIGAN INFLUENCE ON  
TEMPERATURES IN THE EASTERNMOST COUNTIES.  
 
MH  
 

 
   
AVIATION
 
 
ISSUED 1156 AM CDT TUE MAY 19 2026  
 
EXPECT MVFR CEILINGS AHEAD OF AND BEHIND A COLD FRONT THAT IS  
CURRENTLY CROSSING SOUTHERN WI (NOW NEAR MADISON). BREEZY  
SOUTHWEST WINDS WILL BECOME WEST TO NORTHWEST WINDS BEHIND THE  
FRONT THIS AFTERNOON AND EVENING. CEILINGS SHOULD LIFT TO VFR  
LATE THIS AFTERNOON AND THEN DISPERSE TONIGHT AS SKIES GRADUALLY  
CLEAR AS HIGH PRESSURE WORKS INTO THE REGION.  
 
CLOUDS BELOW 5000 FT SHOULD BE PRESENT ON WEDNESDAY, ESPECIALLY  
CLOSER TO LAKE MICHIGAN. WIND SHOULD BE OUT OF THE NORTHEAST  
NEAR THE LAKE AND THEN THE NORTHEAST WINDS WILL EXPAND INLAND  
THROUGH EARLY AFTERNOON.  
 
CRONCE  
 

 
   
MARINE
 
 
ISSUED 1156 AM CDT MON MAY 18 2026  
 
THE MARINE DENSE FOG ADVISORY FOR THE NORTH HALF OF LAKE  
MICHIGAN WAS EXTENDED THROUGH MID AFTERNOON DUE TO RELATIVELY  
MILD AND HUMID AIR FLOWING OVER THE COLD LAKE WATERS. FOG WILL  
LINGER UNTIL THE COLD FRONT MOVES THROUGH.OTHERWISE MODEST TO  
BREEZY SOUTHERLY WINDS WILL PERSIST AHEAD OF THE FRONT, THEN  
SHIFT TO THE WEST-NORTHWEST AND REMAIN BREEZY THROUGH MOST OF  
TONIGHT. HIGH PRESSURE AROUND 30.4 INCHES WILL THEN MOVE INTO  
THE NORTHERN GREAT LAKES FOR WEDNESDAY AFTERNOON INTO THURSDAY.  
LIGHT TO MODEST NORTH TO NORTHEAST WINDS CAN BE EXPECTED.  
 
A SMALL CRAFT ADVISORY IS IN EFFECT FROM SHEBOYGAN TO  
WINTHROP HARBOR THROUGH LATE AFTERNOON FOR BREEZY SOUTHWEST TO  
WEST WINDS.  
 
CRONCE  
 

 
   
MKX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
LM...SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646 UNTIL 4 PM  
TUESDAY.  
 
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-  
LMZ567-LMZ868 UNTIL 3 PM TUESDAY.  
 

 
 

 
 
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