622  
FXUS63 KMKX 180500  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
1200 AM CDT MON MAY 18 2026  
   
KEY MESSAGES
 
 
- DECAYING SQUALL LINE WITH GUSTY WINDS TO MOVE INTO SOUTH  
CENTRAL AND SE WI DURING THE EARLY MORNING HOURS. MARGINAL  
PROBABILITIES FOR SEVERE WIND GUSTS OVER SAID REGION.  
 
- ANOTHER ROUND OF SHOWERS AND STORMS LATE TONIGHT INTO TUESDAY  
WITH A POTENTIAL FOR STRONG TO SEVERE STORMS.  
 
- COOL AND DRIER WEATHER THEN RETURNS FOR MIDWEEK.  
 

 
   
SHORT TERM
 
 
ISSUED 1200 AM CDT MON MAY 18 2026  
 
TODAY THROUGH TUESDAY:  
 
THE NRN PORTION OF THE QLCS OVER NE IA AND SE MN HAS RECENTLY  
PRODUCED SEVERE WIND GUSTS BUT GRADUAL WEAKENING IS EXPECTED AS  
IT MOVES INTO GREATER CIN. FARTHER TO THE SOUTH, THE GUST FRONT  
IS OUTRUNNING THE CONVECTION BUT SPORADIC WIND GUSTS OF 40-50  
MPH ARE STILL OCCURRING. FOR SRN WI, GUSTY WINDS AND SCATTERED  
STORMS WILL CONTINUE TO INITIATE ALONG AND BEHIND THE GUST FRONT  
DURING THE EARLY MORNING HOURS. MUCAPE OF 1500-2000 J/KG WILL  
BE PRESENT BUT WITH HIGH LFCS AT 650-700 MB. THE HIGH LFCS  
SHOULD AID IN THE FURTHER DISSIPATION OF THE ORGANIZED LINE  
AND/OR TRANSITIONING TO ELEVATED SCATTERED STORMS.  
 
DURING THIS TIME, A WAVE OF LOW PRESSURE WILL TRACK ACROSS MN  
TO WRN LAKE SUPERIOR AND BE THE CATALYST TO SHIFTING THE WARM  
FRONT NWD INTO CENTRAL WI. THUS THE LOW STRATUS AND AREAS OF FOG  
TOWARD CENTRAL WI WILL COME TO AN END DURING THE EARLY MORNING  
HOURS. SOME SHOWERS AND STORMS WILL LIKELY LINGER THROUGH LATER  
THIS MORNING, BUT CAPPING WILL SET IN AGAIN AND WILL AID IN  
SOME SCATTERING OF CLOUDS AND TEMPS NEARING 80F FOR THE  
AFTERNOON.  
 
ANOTHER WAVE OF LOW PRESSURE WILL DEVELOP FROM THE CENTRAL  
GREAT PLAINS TO NRN WI FROM LATE MON AFTERNOON UNTIL 12Z TUE,  
WHILE THE MAIN SHORTWAVE TROUGH TRACKS FROM THE CENTRAL ROCKIES  
TO NW WI. THE ACTUAL TRAILING COLD FRONT WILL LIKELY NOT PASS  
UNTIL TUE, BUT THERE IS SOME CONFIDENCE IN ANOTHER ROUND OF  
SHOWERS AND STORMS FOR MAINLY AFTER MIDNIGHT (EARLY TUE AM) AS  
ANOTHER MCS MOVES INTO SRN WI FROM THE WEST. THE MCS MAY ALREADY  
HAVE REACHED THE DISSIPATING STAGE AT THIS TIME, BUT THERE IS  
UNCERTAINTY WITH THE TIMING OF THE EVOLUTION. ONCE AGAIN,  
DAMAGING WIND GUSTS WOULD BE THE MAIN CONCERN. FINALLY, THERE  
MAY BE SOME SHOWER AND STORM DEVELOPMENT WITH THE COLD FRONTAL  
PASSAGE TUE AFTERNOON WITH SEVERE PROBS ARE LOW AT THIS TIME.  
 
GEHRING  
 

 
   
LONG TERM
 
 
ISSUED 1200 AM CDT MON MAY 18 2026  
 
TUESDAY NIGHT THROUGH SUNDAY:  
 
GUSTY NORTHWEST WINDS REMAIN IN PLACE THROUGH TUESDAY NIGHT AS  
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. WINDS GRADUALLY  
DIMINISH INTO WEDNESDAY AS HIGH PRESSURE SETTLES INTO THE REGION.  
TEMPERATURES ARE EXPECTED TO BE BACK INTO THE 60S AND LOW 70S FOR  
HIGHS AND LOWS IN THE UPPER 30S TO MID 40S THROUGH MIDWEEK. HIGH  
PRESSURE REMAINS DOMINANT THROUGH THURSDAY BEFORE PROPAGATING  
EASTWARD INTO THE NORTHEAST U.S. LOW PRESSURE WILL BEGIN TO DEEPEN  
IN THE LEE OF THE COLORADO ROCKIES, EJECTING INTO THE PLAINS  
FRIDAY MORNING. WITH HIGH PRESSURE REMAINING OVER THE NORTHEAST,  
MODELS ARE INDICATING A SPLIT LOW PROGRESSION, WITH ONE PORTION OF  
UPPER LEVEL ENERGY PROPAGATING THROUGH THE LOWER MISSISSIPPI  
VALLEY ALONG A GULF HUMIDITY AXIS, AND THE OTHER PORTION FOLLOWING  
THE LONG WAVE PATTERN NORTHEASTWARD INTO THE WESTERN GREAT LAKES.  
A FEW SHOWERS AND THUNDERSTORMS MAY WORK THEIR WAY IN AS EARLY AS  
THURSDAY NIGHT INTO FRIDAY (15-25%), WITH MORE POTENTIAL FOR  
WIDESPREAD SHOWERS AND THUNDERSTORMS INTO FRIDAY NIGHT AND  
SATURDAY AS THE COLD FRONT FROM THE MIDWEST LOW PHASES WITH THE  
SOUTHERN LOW. CONFIDENCE IN TIMING AND PLACEMENT REMAINS IN  
QUESTION DUE TO MODEL DISCREPANCIES, SO MAINTAINED NBM  
PROBABILITIES FOR THIS UPDATE. PRECIPITATION EXITS SATURDAY NIGHT  
AS RIDGING BEGINS TO BUILD BACK INTO THE SOUTHERN WISCONSIN FROM  
THE CENTRAL PLAINS. EXPECT TEMPERATURES TO RETURN TO THE UPPER 70S  
AND LOW 80S SUNDAY AS WINDS SHIFT TO SOUTHERLY, WITH ADDITIONAL  
CHANCES FOR STORMS SUNDAY NIGHT INTO MONDAY.  
 
MH  
 

 
   
AVIATION
 
 
ISSUED 1200 AM CDT MON MAY 18 2026  
 
STRATUS BELOW 1 KFT AND AREAS OF FOG ARE OCCURRING TOWARD  
CENTRAL WI, BUT VFR CONDITIONS WILL RETURN EARLY THIS MORNING  
ONCE THE WARM FRONT PASSES TO THE NORTH. SCATTERED THUNDERSTORMS  
WITH GUSTY WINDS WILL THEN MOVE ACROSS MUCH OF SRN WI DURING  
THE EARLY MORNING HOURS WITH SOME SHOWERS AND STORMS CONTINUING  
THROUGH LATE THIS MORNING. SCT-BKN040-060 CLOUDS ARE EXPECTED  
DURING THIS TIME BUT AREAS OF MVFR CIGS MAY OCCUR. ANOTHER ROUND  
OF THUNDERSTORMS AND GUSTY WINDS IS THEN FORECAST LATE TNT WITH  
MORE MVFR CIGS POSSIBLE.  
 
GEHRING  
 

 
   
MARINE
 
 
ISSUED 1200 AM CDT MON MAY 18 2026  
 
A WARM FRONT WILL MOVE FROM SOUTHERN LAKE MICHIGAN TO NORTHERN  
LAKE MICHIGAN THIS MORNING. EAST TO NORTHEAST WINDS WILL BECOME  
BREEZY OUT OF THE SOUTH. AREAS OF DENSE FOG MAY OCCUR AT TIMES  
UNTIL THE FRONT PASSES. BREEZY SOUTH WINDS WILL THEN CONTINUE  
THROUGH TODAY INTO TUESDAY FOLLOWED BY A WIND SHIFT TO THE  
NORTHWEST LATE TUESDAY AFTERNOON AND EVENING WITH THE PASSAGE OF  
A COLD FRONT. HIGH PRESSURE AND LIGHT AND VARIABLE WINDS WILL  
THEN TAKE HOLD FROM LATE WEDNESDAY INTO THURSDAY.  
 
A MARINE DENSE FOG ADVISORY IS IN EFFECT FROM SHEBOYGAN TO NORTH  
POINT LIGHTHOUSE UNTIL 3 AM CDT TODAY. THE FOG WILL DISSIPATE  
ONCE THE WARM FRONT MOVES TO THE NORTH, AND SOUTH WINDS AND  
MILDER TEMPERATURES ARRIVE.  
 
GEHRING  
 

 
   
MKX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
LM...DENSE FOG ADVISORY...LMZ643-LMZ644 UNTIL 3 AM MONDAY.  
 

 
 

 
 
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