325
FXUS63 KMKX 271040
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
540 AM CDT SUN SEP 27 2026
KEY MESSAGES
- PATCHY FOG CONTINUES THROUGH DAWN, PRIMARILY FOR LOCATIONS
EAST OF MADISON. FOG MAY BE DENSE IN LOCALIZED SPOTS.
- TEMPERATURES WITHIN A COUPLE DEGREES OF NORMAL OVER THE NEXT
SEVERAL DAYS
- CHANCES FOR RAIN AND A FEW STORMS RETURN LATER TUESDAY INTO
TUESDAY NIGHT
UPDATE
ISSUED 534 AM CDT SUN SEP 27 2026
PATCHY FOG HAS CROPPED UP AGAIN THIS MORNING AND WILL CONTINUE
THROUGH DAWN. MOST OF THIS FOG IS LOCATED FROM MADISON AND
POINTS EASTWARD, WHERE LESS HIGH CLOUDS HAVE LINGERED
OVERNIGHT. DENSE FOG IS ANTICIPATED IN LOCALIZED SPOTS AND LOOKS
TO BE OCCURRING IN JEFFERSON, WAUKESHA, DODGE, AND WASHINGTON
COUNTIES AT THIS TIME. WILL HOLD OFF ON AN ADVISORY AS SUNRISE
WILL OCCUR SOON AND THE FOG WILL MIX OUT WITH TIME.
OTHERWISE, EXPECT A MIX OF SUN AND HIGH CLOUDS TODAY AS RAIN
FROM A SHORTWAVE TO OUR SOUTHWEST DISSIPATES AND SENDS CLOUD
DEBRIS OVERHEAD. HIGHS WILL BE IN THE MID TO UPPER 60S.
CMILLER
SHORT TERM
ISSUED 1127 PM CDT SAT SEP 26 2026
TONIGHT THROUGH MONDAY NIGHT:
MID TO UPPER LEVEL CLOUDS ARE SLOWLY MOVING INTO SOUTHERN
WISCONSIN TONIGHT. THESE UPPER LEVEL CLOUDS WILL ACTIVELY WORK
AGAINST THE DEVELOPMENT OF RADIATION FOG OVERNIGHT. WE CAN'T
COMPLETELY RULE OUT SOME PATCHY FOG DEVELOPING ESPECIALLY IN
AREAS THAT STAY CLEAR WHICH RIGHT NOW IS MOST ALONG AND EAST OF
THE KETTLE MORAINE. LOW LYING AREAS LIKE RIVER VALLEYS AND
MARSHES WILL BE PRIMED WITH ENOUGH LOW LEVEL MOISTURE TO GET
FOG UNDER THE LIGHT AND VARIABLE WINDS TONIGHT. ANY FOG THAT
DOES DEVELOP TONIGHT WILL DISSIPATE SHORTLY AFTER SUNRISE.
MEANWHILE THE SHORTWAVE TROUGH CONTINUES TO APPROACH FROM THE
WEST. DRY AIR WILL CAUSE ANY SHOWERS APPROACHING FROM IOWA TO
FALL APART BEFORE REACHING SOUTHERN WISCONSIN. THIS TREND SHOULD
CONTINUE THROUGH THE OVERNIGHT HOURS UNTIL THE UPPER LEVEL WAVE
HAS MOVED THROUGH.
HIGH PRESSURE AND UPPER LEVEL RIDGING WILL MOVE INTO THE GREAT
LAKES REGION BY MONDAY KEEPING CONDITIONS DRY AND QUIET. OVERCAST
SKIES WITH HIGHS IN THE UPPERS 60S TO LOW 70S AND OVERNIGHT
LOWS IN THE MID 40S TO MID 50S ARE EXPECTED SUNDAY AND MONDAY.
PATTERSON
LONG TERM
ISSUED 1127 PM CDT SAT SEP 26 2026
TUESDAY THROUGH SATURDAY:
THE UPPER LEVEL RIDGE WILL CONTINUE TO GRADUALLY MOVE EASTWARD INTO
MID WEEK. AS THE HIGH MOVES AWAY, SOUTHWEST WINDS ARE EXPECTED TO
RETURN TO THE STATE AND THUS MOISTURE WILL RETURN. WITH THE RIDGE
OVER THE NEW ENGLAND STATES AND A CUT OFF LOW ACROSS THE DESERT
SOUTHWEST, THE WILL BE DEEP MOISTURE RETURNS STRAIGHT OUT OF THE
GULF. PWAT VALUES WILL CLIMB ACROSS WISCONSIN TO AROUND 1.5 INCHES
BY TUESDAY NIGHT. THE WAA WILL BRING TEMPERATURE BACK UP INTO THE
70S AND COULD BRING SOME INSTABILITY BACK TO THE GREAT LAKES REGION
AHEAD OF AN APPROACHING SHORTWAVE.
THE UPPER LEVEL SHORTWAVE IS EXPECTED TO MOVE THROUGH THE GREAT
LAKES REGION TUESDAY NIGHT INTO WEDNESDAY MORNING. MEANWHILE THE
ASSOCIATED SFC LOW, IS EXPECTED TO DEVELOP IN THE LEE OF THE ROCKIES
MOVING NORTHEAST TOWARD WISCONSIN. THERE IS STILL A BIT OF
UNCERTAINTY IN THE EXACT TRACK AND STRENGTH OF THIS SFC LOW,
BUT RAIN CHANCES WILL INCREASE TUESDAY EVENING HIT THERE PEAK
AROUND 60- 80% OVERNIGHT TUESDAY INTO EARLY WEDNESDAY MORNING.
WITH THE WAA AND DEEP MOISTURE RETURNS, THERE WILL BE A
POTENTIAL FOR A FEW RUMBLES OF THUNDER, BUT THE TIMING AND LACK
OF DIURNAL INSTABILITY WILL LIMIT THUNDERSTORM POTENTIAL. NO
SEVERE WEATHER IS EXPECTED. THE HIGH PWATS WILL ALSO MEAN THAT
RAINFALL COULD BE HEAVY AND THERE WILL BE A GOOD WETTING RAIN.
STILL A BIT TOO EARLY TO REALLY TALK ABOUT TOTALS, BUT OF THE
GLOBAL ENSEMBLES THERE'S A ROUGHLY 10-25% CHANCE FOR AN INCH OF
RAIN. THIS CAN A WILL LIKELY CHANGE GIVEN THE UNCERTAINTY IN
TRACK OF THE SFC LOW.
BEYOND THIS AND LOOKING AHEAD TOWARD THE END OF THE WORK WEEK THERE
ARE ADDITIONAL CHANCES FOR RAIN. GLOBAL MODELS AND ENSEMBLES REMAIN
SPLIT ON HOW MUCH MOISTURE WILL RETURN AND THE SPEED OF THE NEXT
INCOMING HIGH PRESSURE SYSTEM. THIS UNCERTAINTY EXTENDS UP TO
THE MID/UPPER LEVELS WITH WITH THE UNCERTATINY OF THE TIMING
AND STRENGTH OF A 500 MB SHORTWAVE AND TROUGH. THIS UNCERTAINTY
CAN BE MOST EASILY SEEN WHEN LOOKING AT THE 500 MB CLUSTER
ANALYSIS. IN THE MEAN TIME THERE ARE POPS SCATTERED THROUGH THE
REST OF THE EXTENDED (AROUND 50% POPS THURSDAY BECOMING 10-20%
FRIDAY THROUGH SATURDAY). AS GUIDANCE COMES TO FURTHER AGREEMENT
THOSE VALUES WILL CHANGE.
PATTERSON
AVIATION
ISSUED 537 AM CDT SUN SEP 27 2026
EXPECT MORNING FOG WHICH MAY BE DENSE IN SPOTS EAST OF KMSN.
VFR CONDITIONS ARE THEN EXPECTED THROUGH THE REST OF THE DAY
AMID LIGHT NORTHEASTERLY TO LIGHT AND VARIABLE WINDS.
CMILLER
MARINE
ISSUED 1127 PM CDT SAT SEP 26 2026
HIGH PRESSURE OF 30.3 INCHES CENTERED NEAR THE JAMES BAY WILL
GRADUALLY MOVE EAST INTO SUNDAY WHILE A SECOND HIGH PRESSURE
AROUND 30.1 INCHES ACROSS THE WESTERN GREAT LAKES REGION REMAINS
NEAR STATIONARY THROUGH MONDAY. THEREFORE, DRY WEATHER AND LIGHT
WINDS ARE EXPECTED INTO EARLY NEXT WEEK.
BREEZY SOUTHERLY WINDS ARE EXPECTED TUESDAY THROUGH THURSDAY NEXT
WEEK, AS HIGH PRESSURE DEPARTS TO THE EAST AHEAD OF AN APPROACHING
TROUGH. WIND GUST TO 25 KNOTS ARE POSSIBLE ALONG WITH BUILDING
WAVES, PARTICULARLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
LAKE.
PATTERSON
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...NONE.
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