750  
FXUS63 KMKX 190434  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
1134 PM CDT MON MAY 18 2026  
   
KEY MESSAGES  
 
- ANOTHER ROUND OF SHOWERS AND STORMS LATE THIS EVENING INTO THE  
OVERNIGHT HOURS. JUST A VERY SMALL POTENTIAL FOR STRONG OR  
SEVERE STORMS.  
 
- 30 PERCENT CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WITH  
THE COLD FRONTAL PASSAGE ON TUESDAY. SEVERE THUNDERSTORMS ARE  
NOT EXPECTED.  
 
- 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.  
 
 
   
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 1134 PM CDT MON MAY 18 2026  
 
NUMEROUS SHOWERS AND SCATTERED STORMS SPREADING WEST TO EAST  
ACROSS SRN WI DURING THE EARLY MORNING HOURS. AREAS OF MVFR  
CIGS AND VSBYS MAY LINGER AFTER THE RAIN. MORE WIDESPREAD MVFR  
CIGS WILL THEN OVERSPREAD SRN WI JUST AFTER SUNRISE AND AHEAD OF  
THE APPROACHING COLD FRONT. LOCALIZED CIGS BELOW 1 KFT ARE  
POSSIBLE OVER SOUTH CENTRAL WI. THE CIGS WILL DISSIPATE AFTER  
THE COLD FRONTAL PASSAGE FROM MID TO LATE AFTERNOON. GUSTY SWLY  
WINDS TO 30 KTS ARE EXPECTED ON TUE ESPECIALLY OVER ERN WI. VFR  
CONDITIONS FOR TUE NT.  
 
GEHRING  
 
 
   
MARINE  
 
ISSUED 1134 PM CDT MON MAY 18 2026  
 
A DENSE FOG ADVISORY IS IN EFFECT TONIGHT THROUGH TUESDAY MORNING  
FOR THE NORTH HALF OF THE LAKE AS RELATIVELY MILD AND HUMID AIR  
FLOWS OVER THE COLD LAKE WATERS. OTHERWISE MODEST TO BREEZY  
SOUTHERLY WINDS WILL DEVELOP TONIGHT AND LAST INTO EARLY TUESDAY  
AFTERNOON, THEN FOLLOWED BY THE PASSAGE OF A COLD FRONT. WINDS  
WILL SHIFT TO NORTHWESTERLY WITH THE COLD FRONTAL PASSAGE AND  
REMAIN A BIT BREEZY. SCATTERED THUNDERSTORMS CAN BE EXPECTED OVER  
THE CENTRAL AND SOUTHERN PORTION OF THE LAKE LATE TONIGHT INTO  
TUESDAY. 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 FROM EARLY MORNING TUESDAY INTO THE AFTERNOON  
FOR BREEZY SOUTHWEST WINDS.  
 
GEHRING  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...NONE.  
LM...SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646...4 AM  
TUESDAY TO 4 PM TUESDAY.  
 
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-  
LMZ567-LMZ868 UNTIL NOON TUESDAY.  
 
 
 
 
 
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