711  
FXUS63 KMKX 270018  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
718 PM CDT FRI MAY 26 2017  
   
UPDATE
 
THE RAIN HAS EXITED THE AREA WITH CLEARING SKIES OVER  
MUCH OF SRN WI. A WEAK WEST TO EAST SFC RIDGE WILL PREVAIL OVER  
THE AREA TNT-SAT. THE CLOUDS AND RAIN HAS LED TO LOW DEWPOINT  
DEPRESSIONS OVER SE WI SO MAY SEE SOME FOG DEVELOPMENT BY LATE  
EVENING WHILE IT WILL TAKE LONGER OVER THE REMAINDER OF SRN WI.  
ANY FOG SHOULD QUICKLY DISSIPATE SAT AFTER SUNRISE. OTHERWISE A  
MILD DAY IS EXPECTED WITH A LAKE BREEZE OVER FAR ERN WI. MIDDLE TO  
HIGH CLOUDS MAY INCREASE LATE IN THE DAY.  
 

 
   
AVIATION(00Z TAFS)
 
EXPECT FOG TO EVENTUALLY DEVELOP ACROSS SRN  
WI TNT POSSIBLY OCCURRING BY LATE EVENING OVER SE WI WHERE  
DEWPOINT DEPRESSIONS ARE ALREADY LOW. FOG WILL DEVELOP ELSEWHERE  
AFTER MIDNIGHT WITH VSBYS DROPPING ANYWHERE FROM 1-5SM WITH  
LOCALLY LOWER VALUES. THE FOG SHOULD REMAIN SHALLOW AND DISSIPATE  
WITHIN 2-4 HOURS AFTER SUNRISE. VFR CONDITIONS THE REMAINDER OF  
THE DAY.  
 

 
   
PREV DISCUSSION
 
(ISSUED 339 PM CDT FRI MAY 26 2017)  
 
SHORT TERM...  
 
TONIGHT AND SATURDAY... FORECAST CONFIDENCE IS MEDIUM.  
 
SHOWERS ASSOCIATED WITH A MCV (MESOSCALE CONVECTIVE VORTEX) THAT  
IS ROLLING ACROSS NORTHERN IL AND SOUTHERN WI WILL EXIT SOUTHEAST  
WI BY EARLY EVENING. THE THUNDER HAS REMAINED CONFINED TO SOUTH OF  
THE WI/IL BORDER TODAY, BUT CAN'T RULE OUT A STRAY RUMBLE ACROSS  
THE SOUTHERN WI COUNTIES. RAIN IS BECOMING STEADIER NOW AND UP TO  
A QUARTER INCH IS POSSIBLE SOUTH OF I-94.  
 
CLEAR SKIES ARE EXPECTED BEHIND THIS SYSTEM. THIS SHOULD LEAD TO  
SOME PATCHY RADIATIONAL FOG OVERNIGHT. MORE FOG IS POSSIBLE OVER  
LAKE MICHIGAN DUE TO HIGH DEWPOINTS OVER RELATIVELY COOL WATER, SO  
KEPT THE MARINE DENSE FOG ADVISORY GOING. THIS FOG COULD ADVECT  
INLAND A BIT EARLY SATURDAY MORNING.  
 
WE SHOULD HAVE QUIET AND WARM WEATHER ACROSS SOUTHERN WI FOR MOST  
OF THE DAY ON SATURDAY. HIGHS EXPECTED IN THE UPPER 70S INLAND AND  
AROUND 70 NEAR THE LAKESHORE.  
 
SATURDAY NIGHT AND SUNDAY... FORECAST CONFIDENCE IS MEDIUM.  
 
IT'S NOT UNTIL THE EARLY EVENING HOURS WHEN A WEAK COLD FRONT  
BECOMES THE FOCUS FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS. NOT  
ALL MODELS AGREE ON TIMING, BUT THE MAJORITY SUGGEST THAT THE  
FRONT AND ASSOCIATED SHOWERS SHOULDN'T MAKE IT INTO SOUTH CENTRAL  
WI UNTIL THE EARLY MORNING HOURS ON SUNDAY. THIS WOULD KEEP OUR  
INSTABILITY VERY LOW.  
 
MEANWHILE, ANOTHER MCV IS EXPECTED TO ROLL ACROSS NORTHERN IL  
SATURDAY NIGHT. SOUTHERN WI COULD BE ON THE NORTHERN FRINGE OF  
THOSE SHOWERS AND ISOLATED STORMS ONCE AGAIN.  
 
YET ANOTHER WEAK COLD FRONT COULD TRIGGER SHOWERS AND ISOLATED  
STORMS ACROSS MAINLY NORTHERN WI MIDDAY SUNDAY, WITH A FEW  
TRAILING SHOWERS LINGERING INTO THE AFTERNOON.  
 
BOTTOM LINE IS CLOUD COVER WITH A CHANCE FOR RAIN AT TIMES AND  
HIGHS AROUND 70.  
 
LONG TERM...  
 
MONDAY THROUGH WEDNESDAY... FORECAST CONFIDENCE IS MEDIUM.  
 
A CLOSED UPPER LOW WILL SET UP OVER THE GREAT LAKES FOR THE FIRST  
HALF OF NEXT WEEK. THIS WILL BRING SCATTERED SHOWERS AND ISOLATED  
THUNDERSTORMS TO MUCH OF WI EACH AFTERNOON. MAX TEMPS WILL BE IN  
THE UPPER 60S.  
 
AVIATION(18Z TAFS)...  
 
UPPER LEVEL DISTURBANCE MOVING OUT OF NE IA WILL SPREAD SHRAS  
ACROSS STHRN WI THIS AFTN. MOST OF THE ACTIVITY SHOULD REMAIN  
ALONG AND S OF I-94. SYSTEM IS FCST TO PULL AWAY THIS EVNG  
LEAVING SCATTERED VFR CLOUDS TONIGHT. WINDS BECOME LGHT/VRB  
OVERNIGHT AS WEAK SFC RIDGE MOVES THRU WHICH WILL SET THE STAGE  
FOR SOME RADIATION FOG. BEST CHANCES WILL BE ACROSS SW WI WHICH  
SHOULD BE THE FIRST AREAS FOR CLOUDS TO THIN TONIGHT. ANOTHER AREA  
OF CONCERN IS A BAND OF FOG THAT DVLPD THIS MRNG ALONG THE  
LAKESHORE. EXPECT THIS BAND TO PERSIST INTO SAT WITH IFR VSBYS.  
 
MARINE...  
 
WEBCAMS NEAR THE LAKESHORE ARE SHOWING CLEAR CONDITIONS THIS  
AFTERNOON AND CLOUDS HAVE OVERSPREAD THE AREA SO WE CANNOT SEE THE  
EXTENT OF FOG OVER THE LAKE VIA SATELLITE AT THIS TIME. WILL KEEP  
THE MARINE DENSE FOG ADVISORY GOING UNTIL MIDDAY SATURDAY DUE TO  
FAVORABLE CONDITIONS FOR AREAS OF DENSE FOG DURING THE OVERNIGHT  
HOURS.  
 

 
   
MKX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
LM...DENSE FOG ADVISORY UNTIL 1 PM CDT SATURDAY FOR LMZ643>646.  
 

 
 

 
 
UPDATE...GEHRING  
TONIGHT/SATURDAY AND AVIATION/MARINE...CRONCE  
SATURDAY NIGHT THROUGH FRIDAY...CRONCE  
 
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