311
FXUS63 KMKX 201145 AAA
AFDMKX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
645 AM CDT SUN SEP 20 2026
KEY MESSAGES
- FLOOD WATCH WILL BE ALLOWED TO EXPIRE AT 7 AM CDT FOR THE
SOUTHERN HALF OF THE FORECAST AREA. MODERATE TO HEAVY RAIN
SHOULD CONTINUE TO SLOWLY TAPER OFF INTO THIS MORNING, PUSHING
SOUTH OF THE AREA BY MIDDAY TO EARLY AFTERNOON.
- PROLONGED PERIOD OF HIGH SWIMMING RISK CONDITIONS CONTINUES
INTO TUESDAY AT ALL LAKE MICHIGAN BEACHES, AND MAY NEED TO BE
EXTENDED INTO WEDNESDAY EVENING.
UPDATE
ISSUED 646 AM CDT SUN SEP 20 2026
THE FLOOD WATCH WILL BE ALLOWED TO EXPIRE AT 7 AM CDT THIS
MORNING FOR THE SOUTHERN PORTIONS OF THE FORECAST AREA. THE
LINGERING MODERATE TO SOMETIMES HEAVY RAINFALL RATES OVER THIS
AREA SHOULD CONTINUE TO GRADUALLY TAPER OFF INTO THIS MORNING,
AND EVENTUALLY MOVE SOUTH OF THE AREA BY MIDDAY OR EARLY
AFTERNOON. WILL STILL WATCH FOR SOME URBAN AND SMALL STREAM
FLOODING AND RIVER RISES, BUT THE INCREASING NORTHEAST WINDS
SHOULD CONTINUE TO HELP PUSH BACK THE NORTHERN EDGE OF THE RAIN
INTO THIS MORNING, AS WELL AS HELPING TO ERODE IT.
GUSTY NORTHEAST WINDS TODAY INTO TONIGHT ARE EXPECTED, BECOMING
MORE EAST TO NORTHEAST ON MONDAY. LOW CLOUDS SHOULD LINGER THIS
MORNING, BEFORE SLOWLY RISING THIS AFTERNOON AND TONIGHT. THERE
COULD BE SOME BREAKS IN THE CLOUDS TONIGHT INTO MONDAY, THOUGH
THERE SHOULD STILL BE MOSTLY CLOUDY SKIES. AN ADVANCING
SHORTWAVE TROUGH AND LINGERING MOISTURE ALOFT MAY HELP BRING
SOME SHOWERS INTO THE AREA TONIGHT INTO MONDAY NIGHT. KEPT 20 TO
30 PERCENT CHANCES IN SOUTHERN AND WESTERN PARTS OF THE AREA FOR
NOW. TEMPERATURES SHOULD REMAIN COOL IN THE MIDDLE TO UPPER 60S
TODAY AND MONDAY.
THE BEACH HAZARDS STATEMENT FOR A HIGH SWIM RISK WILL CONTINUE
INTO TUESDAY FOR THE BEACHES ALONG LAKE MICHIGAN, FOR GUSTY
EAST TO NORTHEAST WINDS AND BUILDING WAVES OF 5 TO 11 FEET. THIS
MAY NEED TO BE EXTENDED INTO WEDNESDAY NIGHT, AS CONDITIONS MAY
LINGER. THESE CONDITIONS WILL RESULT IN DANGEROUS SWIMMING
CONDITIONS, SO STAY OUT OF THE WATER.
WOOD
SHORT TERM
ISSUED 1112 PM CDT SAT SEP 19 2026
CURRENT OVERNIGHT THROUGH SUNDAY NIGHT:
A BAND OF MODERATE RAIN IS CURRENTLY ANGLED FROM NORTHERN DANE
COUNTY THROUGH NORTHERN RACINE COUNTY IN ASSOCIATION WITH LIFT
FROM 925MB FRONTOGENESIS. RAINFALL HAS BEEN PRETTY EFFICIENT
WITHIN THIS BAND, WITH 0.5 INCH ACCUMULATIONS RECORDED WITHIN
ONE HOUR. THIS BAND IS GENERALLY PUSHING E-SE AND SHOULD PUSH
OUT OVER LAKE MICHIGAN IN A PROGRESSIVE MANNER OVER THE NEXT FEW
HOURS.
MEANWHILE, CONVECTION IS CURRENTLY BLOSSOMING SOUTH OF THE
WISCONSIN/ILLINOIS BORDER AS WAA CAUSES UPLIFT OVER A SFC
BOUNDARY. AS THE NIGHT GOES ON, HIGH PRESSURE FROM CENTRAL
CANADA IS EXPECTED BUILD SOUTHWARD INTO THE UPPER GREAT LAKES,
INCREASING THE SFC PRESSURE GRADIENT AND GENERATING
NORTHEASTERLY FLOW, WHICH WILL CONTINUE TO KEEP THE SURFACE
BOUNDARY SOUTH OF THE BORDER. THE COMPRESSION OF THE ENVIRONMENT
BETWEEN THE HIGH AND THE SFC BOUNDARY WILL ALSO FURTHER
INTENSIFY THE CONVECTION OVER ILLINOIS. IT IS PROJECTED THAT
SOME OF THIS CONVECTION WILL DEAL A GLANCING BLOW OF RAIN TO THE
SOUTHERN WISCONSIN COUNTIES ALONG THE WISCONSIN AND ILLINOIS
BORDER GENERALLY FROM 3AM ONWARD. WHILE THE HEAVIEST RAIN WILL
STAY IN ILLINOIS, AND ADDITIONAL INCH TO INCH AND A HALF OF RAIN
MAY OCCUR DURING THE EARLY MORNING HOURS IN THESE COUNTIES. A
FLOOD WATCH WILL STAY OUT ALONG THE WI/IL BORDER UNTIL 7AM TO
ACCOUNT FOR THE POSSIBILITY OF THIS RAIN OVERNIGHT.
RAIN SHOULD QUICKLY END THROUGH THE POST DAWN HOURS OF THE
MORNING ON SUNDAY AS THE INFLUENCE OF THE HIGH PRESSURE
CONTINUES TO PUSH INTO THE UPPER GREAT LAKES REGION. BY THE MID
TO LATE AFTERNOON, SOME BREAKS IN THE CLOUDS MAY OCCUR OVER
EAST-CENTRAL TO SOUTH CENTRAL WISCONSIN. WITH THE STRONGER
PRESSURE GRADIENT OVER THE REGION, WIND GUSTS FROM 20 MPH INLAND
TO 30MPH NEAR THE LAKE WILL BE POSSIBLE.
THE STRONG WINDS WILL DRIVE HIGH ONSHORE WAVES AND RIP CURRENTS
AT ALL LAKE MICHIGAN BEACHES. A BEACH HAZARD STATEMENT IS IN
EFFECT FROM NOW THROUGH TUESDAY OWING TO THE LONG DURATION
HAZARDS SWIMMING CONDITIONS.
CMILLER
LONG TERM
ISSUED 1148 PM CDT SAT SEP 19 2026
MONDAY THROUGH FRIDAY:
HIGH PRESSURE WILL CONTINUE TO LINGER OVER THE NORTHERN GREAT
LAKES MONDAY AHEAD OF AN APPROACHING CUTOFF LOW OVER IOWA.
CHANCES FOR SCATTERED RAIN (15 TO 30% POPS) WILL PERSIST THROUGH
THE DAY AS SOME MOISTURE TRIES TO WORK INTO THE AREA FROM THE
CUTOFF LOW, BUT ULTIMATELY RUNS INTO THE SUBSIDENCE OF THE
HIGH. THE CUTOFF LOW SHOULD LIFT BACK INTO THE BACKGROUND ZONAL
FLOW ALOFT MONDAY NIGHT INTO TUESDAY AND PRECIP CHANCES SHOULD
LARGELY END BY TUESDAY MORNING.
DRY CONDITIONS THEN LOOK TO BE IN STORE FOR THE REST OF THE
EXTENDED PERIOD. SOME RESIDUAL TROUGHING ALOFT WILL KEEP US COOL
THROUGH THE MID WEEK PERIOD WITH HIGHS IN THE LOW TO MID 60S.
70S THEN RETURN FOR THE UPCOMING WEEKEND AS RIDGING BEGINS TO
BUILD OVER THE UPPER MS VALLEY.
CMILLER
AVIATION
ISSUED 646 AM CDT SUN SEP 20 2026
THE LINGERING MODERATE TO SOMETIMES HEAVY RAINFALL OVER MADISON
AND MILWAUKEE AND TERMINALS TO THE SOUTH SHOULD CONTINUE TO
GRADUALLY TAPER OFF INTO THIS MORNING, AND EVENTUALLY MOVE SOUTH
OF THIS AREA BY MIDDAY OR EARLY AFTERNOON. THE INCREASING
NORTHEAST WINDS SHOULD CONTINUE TO HELP PUSH BACK THE NORTHERN
EDGE OF THE RAIN INTO THIS MORNING, AS WELL AS HELPING TO ERODE
IT. THERE IS SOME 1 TO 4 MILE VISIBILITY WITHIN THE RAIN, WITH
MILWAUKEE SEEING LOCALLY LOWER VALUES TO 1/2 MILE AT TIMES.
THESE SHOULD IMPROVE TO GREATER THAN 6 MILES ONCE THE RAIN MOVES
OUT.
GUSTY NORTHEAST WINDS TODAY INTO TONIGHT ARE EXPECTED, BECOMING
MORE EAST TO NORTHEAST ON MONDAY. LOW CLOUDS WITH CEILINGS OF
300 TO 800 FEET AGL SHOULD LINGER THIS MORNING, BEFORE SLOWLY
RISING THIS AFTERNOON ABOVE 1500 TO 2500 FEET AGL. THEY SHOULD
RISE ABOVE 3500 FEET AGL TONIGHT, THOUGH MAY DROP BACK BELOW
3000 FEET AGL MONDAY MORNING. THERE COULD BE SOME BREAKS IN THE
CLOUDS TONIGHT INTO MONDAY.
SOME SHOWERS MAY MOVE INTO THE AREA TONIGHT INTO MONDAY NIGHT,
BUT KEPT MENTION OUT OF TAFS FOR NOW.
WOOD
MARINE
ISSUED 646 AM CDT SUN SEP 20 2026
LOW PRESSURE AROUND 29.8 INCHES WILL MOVE FROM SOUTHEAST IOWA
INTO THE OHIO VALLEY TODAY INTO MONDAY. MEANWHILE, HIGH PRESSURE
AROUND 30.4 INCHES WILL STRENGTHEN AND MOVE EAST INTO ONTARIO
TODAY INTO MONDAY, THEN INTO QUEBEC FOR MONDAY NIGHT INTO
WEDNESDAY. GUSTY NORTHEAST WINDS ARE EXPECTED TODAY INTO
TONIGHT, BECOMING EAST AND REMAINING GUSTY MONDAY INTO
WEDNESDAY. A FEW GALE FORCE GUSTS MAY OCCUR TODAY INTO MONDAY,
MAINLY OVER SOUTHERN PORTIONS OF THE LAKE. BUILDING WAVES ARE
EXPECTED OVER WESTERN PORTIONS OF THE LAKE TODAY INTO THE MIDDLE
OF THE WEEK. LIGHTER EASTERLY WINDS SHOULD THEN LINGER FOR
THURSDAY INTO FRIDAY, AS THE HIGH PRESSURE SYSTEM SLOWLY MOVES
FURTHER EAST.
A SMALL CRAFT ADVISORY REMAINS IN EFFECT INTO TUESDAY EVENING
FOR ALL OF THE NEARSHORE WATERS OF LAKE MICHIGAN. GUSTY EAST TO
NORTHEAST WINDS AND BUILDING WAVES OF 5 TO 11 FEET ARE EXPECTED
DURING THIS PERIOD. A FEW GALE FORCE GUSTS MAY OCCUR TODAY INTO
MONDAY AS WELL. THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED
INTO WEDNESDAY NIGHT, AS WINDS AND WAVES MAY REMAIN HIGH ENOUGH.
WOOD
MKX WATCHES/WARNINGS/ADVISORIES
WI...BEACH HAZARDS STATEMENT...WIZ052-WIZ060-WIZ066-WIZ071-WIZ072
UNTIL 7 PM TUESDAY.
FLOOD WATCH...WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-WIZ067-WIZ068-
WIZ069-WIZ070-WIZ071-WIZ072 UNTIL 7 AM SUNDAY.
LM...SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646 UNTIL 7 PM
TUESDAY.
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