260  
FXUS63 KMKX 220401  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
1101 PM CDT THU SEP 21 2017  
   
UPDATE
 
 
VERY QUIET ACROSS THE AREA OVERNIGHT. THE ONLY THREAT FOR FOG IS  
CLOSE TO LAKE MICHIGAN. IF WE SEE ANY DENSE FOG, IT SHOULD STAY  
CLOSE TO THE SHORE. THERE'S A BETTER CHANCE FOR IT TO SPREAD  
INLAND UP TOWARD SHEBOYGAN. AT THIS POINT THE GOES16 MICROPHYSICS  
IMAGERY IS ONLY REALLY SHOWING THE FOG AROUND THE MANITOWOC AREA  
AND POINTS NORTH.  
 

 
   
AVIATION(06Z TAFS)
 
 
FOG ASSOCIATED WITH LAKE MICHIGAN WILL BRING SOME MVFR VSBYS TO  
KMKE/KUES/KENW TAF SITES THROUGH ABOUT 12-13Z FRIDAY. IT COULD  
BECOME IFR VERY CLOSE TO THE SHORELINE. OTHERWISE, LOOK FOR VFR  
CONDITIONS WITH MOSTLY CLEAR SKIES ONCE THE FOG DISSIPATES. WINDS  
WILL BE SOUTHERLY.  
 

 
   
MARINE
 
 
A MARINE DENSE FOG ADVISORY HAS BEEN ISSUED FOR PORT WASHINGTON  
AND POINTS NORTH. THE FOG SHOULD DISSIPATE BY MID MORNING ON  
FRIDAY. OTHERWISE, WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT  
ADVISORY LEVELS INTO THE WEEKEND.  
 

 
   
PREV DISCUSSION
 
(ISSUED 851 PM CDT THU SEP 21 2017)  
 
UPDATE...  
 
THE MAIN CONCERN TONIGHT IS THE POSSIBLE DEVELOPMENT OF FOG NEAR  
THE LAKE FROM PORT WASHINGTON NORTH TOWARD SHEBOYGAN. SO FAR, THE  
FOG HAS STAY UP BY MANITOWOC AND POINTS NORTH. MUCH OF THE SHORT  
RANGE GUIDANCE DOES SHOW SOME FOG PUSH IN, BUT IT'S TRANSIENT AND  
MOVES QUICKLY NORTH WITH TIME. SO CONFIDENCE THAT IT WILL BECOME  
A PROBLEM IS RATHER LOW AT THIS TIME. WE'LL KEEP AN EYE ON TRENDS  
AND ISSUE ANY DENSE FOG ADVISORIES IF NEEDED.  
 
MARINE...  
 
THERE COULD BE SOME FOG DEVELOPING OUT OVER THE WATER GIVEN OUR  
WARM AND HUMID AIRMASS. SO FAR, IT APPEARS THE FOG WILL MOSTLY  
STAY NORTH OF SHEBOYGAN, BUT MARINERS SHOULD BE PREPARED FOR FOG.  
OTHERWISE, WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY  
LEVELS INTO THE WEEKEND.  
 
PREV DISCUSSION... (ISSUED 545 PM CDT THU SEP 21 2017)  
 
AVIATION(00Z TAFS)...  
 
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. WINDS WILL  
REMAIN SOUTHERLY LESS THAN 10 KNOTS.  
 
PREV DISCUSSION... (ISSUED 245 PM CDT THU SEP 21 2017)  
 
SHORT TERM...  
 
TONIGHT AND FRIDAY - CONFIDENCE...MEDIUM TO HIGH  
THE MAIN STORY WILL CONTINUE TO BE THE UNSEASONABLE HEAT AND  
HUMIDITY. THE RETURN FLOW AROUND THE DEPARTING HIGH WILL SETUP  
OVERNIGHT AND PICK UP EVEN FURTHER ON FRIDAY. THE 500 MILLIBAR  
HEIGHTS WILL GRADUALLY BUILD UP AS WELL WITHIN THE BROADLY  
ANTICYCLONIC SOUTHWEST MID LEVEL FLOW. THE SOUTHERLY FLOW WILL  
REINFORCE 925 TEMPS IN THE MID 20S CELSIUS. SO EXPECTING NEAR  
RECORD HIGH MINIMUMS TONIGHT WITH SOME RECORD HIGHS IN JEOPARDY  
FOR FRIDAY WITH HIGHS PUSHING TO NEAR 90.  
 
FRIDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE HIGH.  
 
A STRONG UPPER RIDGE FROM THE CENTRAL USA TO THE ERN GREAT LAKES  
WILL MOVE SLOWLY TO THE MID ATLANTIC STATES DURING THIS PERIOD.  
AT THE SFC, HIGH PRESSURE WILL REMAIN CENTERED OVER THE ERN GREAT  
LAKES AND MID ATLANTIC STATES WITH A N-S SFC TROUGH/COLD FRONT  
FROM THE SRN GREAT PLAINS TO NE MN OR NW WI. A LIGHT SLY FLOW WILL  
PREVAIL OVER SRN WI WITH CONTINUED VERY WARM AND HUMID CONDITIONS.  
RECORD HIGH TEMPS ARE POSSIBLE INLAND FOR SAT-SUN WHILE A LAKE MI  
LAKE BREEZE IS EXPECTED EACH AFTERNOON.  
 
LONG TERM...TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE  
MEDIUM.  
 
AN UPPER TROUGH LIFTING NEWD FROM THE WRN USA MAY INDUCE  
CYCLOGENESIS ALONG OVER ONTARIO, CANADA. THIS WOULD DRIVE A COLD  
FRONT THROUGH SRN WI EITHER TUE OR WED WITH CHANCES OF SHOWERS OR  
STORMS. HIGH TEMPS SHOULD COOL INTO THE UPPER 60S FOR WED-THU.  
 
AVIATION(18Z TAFS)...OVERALL VFR PERIOD EXPECTED AS RETURN FLOW  
SETS UP. LOOKS LIKE ENOUGH WIND OFF THE DECK TO KEEP WIDESPREAD  
FOG AT BAY. BUT SOME PATCHY FOG NOT OUT OF THE QUESTION. SOME  
CONCERN FOR LLWS ACROSS PARTS OF SC WI AS THE LOW LEVEL FLOW  
STRENGTHENS ABOVE THE INVERSION. SURFACE SSE FLOW PICKS UP FOR  
FRIDAY WITH LITTLE CLOUD COVER AND BUILDING 500 MILLIBAR HEIGHTS.  
 
MARINE...WINDS WILL BE ON THE LIGHT SIDE RIGHT INTO THE UPCOMING  
WEEKEND, WITH LOW WAVES EXPECTED AS A RESULT.  
 

 
   
MKX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
LM...DENSE FOG ADVISORY UNTIL 10 AM CDT FRIDAY FOR LMZ643.  
 

 
 

 
 
UPDATE...DAVIS  
TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR  
FRIDAY NIGHT THROUGH THURSDAY...GEHRING  
 
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