778
FXUS63 KMKX 131445
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
945 AM CDT SUN SEP 13 2026
KEY MESSAGES
- UPDATED FORECAST FOR TODAY TO ADD SHOWERS (60 PERCENT WITH THE
EXCEPTION OF 20-50 PERCENT TOWARD CENTRAL WI).
- ACTIVE START TO NEXT WEEK, WITH MULTIPLE PERIODS OF SHOWERS
AND THUNDERSTORMS EXPECTED MONDAY EVENING THROUGH AT LEAST
TUESDAY, AND POSSIBLY INTO WEDNESDAY NEAR THE WI/IL BORDER.
SOME STORMS COULD PRODUCE HEAVY RAINFALL AND SOME GUSTY WINDS.
- GALES ARE POSSIBLE MONDAY NIGHT INTO TUESDAY MORNING ACROSS
THE LAKE MICHIGAN OPEN WATERS AS INCREASING SOUTH WINDS
DEVELOP. A GALE WATCH HAS BEEN ISSUED FOR THE NORTHERN TWO-
THIRDS OF THE OPEN WATERS OF LAKE MICHIGAN. A SMALL CRAFT
ADVISORY IS LIKELY MONDAY AFTERNOON INTO TUESDAY MORNING FOR
THE NEARSHORE WATERS.
- HIGH SWIM RISK IS EXPECTED MONDAY AFTERNOON INTO TUESDAY.
UPDATE
ISSUED 945 AM CDT SUN SEP 13 2026
INCREASED RAIN CHANCES TO 60 PERCENT TODAY FOR MUCH OF SRN WI
WITH 20-50 PERCENT TOWARD CENTRAL WI. A FEW VORTICITY MAXIMUMS
FROM SRN SD TO SRN MN AND NRN IA WILL COINCIDE WITH STRONG MID
LEVEL FRONTOGENESIS AS IT MOVES ACROSS SRN WI FROM 16-20Z.
DESPITE DRY LOW LEVELS, THE MID LEVEL LIFT AND SATURATION SHOULD
BE ENOUGH FOR LIGHT RAINFALL. MEASURABLE RAIN IS OCCURRING OVER
NRN IA WITH A VERY LIGHT BAND OF RAIN OVER FAR SRN MN THAT MAY
INTENSIFY A BIT AS IT SHIFTS ESEWD ACROSS SRN WI. COLD
ADVECTION WILL INTENSIFY AFTERWARD. THE CLOUDS, A COUPLE HOURS
OF LIGHT RAIN, AND COLD ADVECTION WILL KEEP THE TEMPS DOWN
TODAY.
GEHRING
SHORT TERM
ISSUED 1202 AM CDT SAT SEP 12 2026
CURRENT OVERNIGHT THROUGH TONIGHT:
CONDITIONS WILL REMAIN QUIET OVERNIGHT AS HIGH PRESSURE REMAINS
OVERHEAD. THE DRY AIR PRESENT AND CLEAR SKIES WILL ALLOW
TEMPERATURES TO DROP INTO THE LOW 50S.
AFTER DAYBREAK TODAY, THE BASE OF A TROUGH IS EXPECTED TO PIVOT
OVER THE STATE, BRINGING A 300MB JET STREAK WITH IT. STRONG
700MB FGEN IS EXPECTED AT THE BASE OF THIS TROUGH, AND THIS FGEN
SHOULD MOVE ALONG AND SOUTH OF THE WI/IL BORDER LATE THIS
MORNING AND INTO THE AFTERNOON. THE FGEN WILL DRIVE LIFT AND
SATURATION ALOFT JUST ABOVE THE 700MB LEVEL, BUT A MODERATELY
STRONG 1022MB HIGH PRESSURE WILL REMAIN AT THE SURFACE. AS SUCH,
A POCKET OF DRY AIR 1 TO 3KM DEEP NEAR THE SURFACE FROM THE
HIGH PRESSURE MAY EAT INTO A LOT OF THE POTENTIAL RAIN TODAY.
STILL, AREAS IMMEDIATELY ALONG THE WI/IL BORDER MAY SATURATE
ENOUGH TO BEAT THE DRY LAYER AND SQUEAK OUT A COUPLE HUNDREDTHS
OF RAIN, WITH AREAS FURTHER NORTH TO NEAR I-94 SEEING SPRINKLES.
WITH THE RAIN EVAPORATING INTO DRY AIR NEAR THE SURFACE AND THE
PRESENCE OF CLOUD COVER, TODAY IS LIKELY TO BE COOL, WITH HIGHS
IN THE MID TO UPPER 60S.
RAIN LARGELY ENDS LATE THIS AFTERNOON, WITH SKIES QUICKLY
CLEARING OUT. THE HIGH PRESSURE CENTER IS EXPECTED TO MOVE
OVERHEAD TONIGHT. CLEAR SKIES AND DRY TD'S WILL ALLOW
TEMPERATURES TO DIP INTO THE 40S FOR OVERNIGHT LOWS.
CMILLER
LONG TERM
ISSUED 1223 AM CDT SAT SEP 12 2026
MONDAY THROUGH FRIDAY:
HIGH PRESSURE SHOULD SLOWLY PUSH EAST MONDAY MORNING, KEEPING
THE MORNING HOURS MOSTLY DRY. BY NOON WARM ADVECTION IS
EXPECTED TO SURGE NORTH BETWEEN THE EXITING HIGH PRESSURE
SYSTEM, AND AN OCCLUDING LOW PRESSURE SYSTEM OVER THE CENTRAL TO
NORTHERN GREAT PLAINS. A SWATH OF RAIN WILL RIDE THE WAA WAVE
INTO WISCONSIN AND MONDAY AFTERNOON LOOKS TO FEATURE SOME STEADY
LIGHT TO MODERATE RAIN, WITH SOME HEAVIER RAIN TIED TO
EMBEDDED THUNDERSTORMS, AS A FEW HUNDRED J/KG OF MUCAPE WILL
ARRIVE WITH THE RAIN. SOME OF THE DOWNPOURS WITH THE EMBEDDED
THUNDERSTORMS COULD BE HEAVY, AS PWATS OF 1.7 TO 1.8 INCHES ARE
EXPECTED TO ARRIVE MONDAY AFTERNOON. IT DOES LOOK LIKE EARLIER
CONCERNS FOR SEVERE WEATHER HAVE LESSENED AS THE WARM SECTOR OF
THE OCCLUDING LOW SHOULD STAY TO OUR WEST IN IOWA WHILE WE SEE
WEAK ELEVATED CONVECTION THROUGH THE AFTERNOON AND EARLY
EVENING.
BY MONDAY NIGHT, THE MORE DEFINED WARM SECTOR FROM EARLIER IN
THE DAY WILL GIVE WAY INTO AN ELONGATED BAROCLINIC ZONE. THIS
BAROCLINIC ZONE WILL THEN SINK SOUTH-SOUTHEAST AS A COLD FRONT
FROM EARLY MORNING TUESDAY TO MIDDAY. CONVECTION IS EXPECTED TO
LIGHT UP ALONG THE FRONT OVERNIGHT, AND TRACK FROM SOUTHWEST TO
NORTHEAST ALONG THE SAGGING FRONT. WITH THE HIGH PWATS MENTIONED
BEFORE, THESE STORMS MAY CAUSE SOME HEAVY RAINFALL. AN AGGREGATE
OF THE CAMS, DETERMINISTIC MODELS, AND GFS AND ECMWF ENSEMBLES
GENERALLY SHOW 0.5 TO 2 INCHES OF ACCUMULATION ON THE LOWER AND
UPPER ENDS OF THE ENVELOPES FROM MONDAY AFTERNOON THROUGH
TUESDAY MORNING, BUT LOCALLY HIGHER AMOUNTS MAY OCCUR WHERE
STORMS TRACK REPEATEDLY. SOME GUSTY WINDS CAN'T BE RULED OUT
WITH THESE STORMS MONDAY NIGHT INTO TUESDAY MORNING, GIVEN THE
WATER LOAD IN THE STORMS AND MORE MUCAPE NEAR 1000 J/KG OVER THE
AREA.
LIGHTER, SHOWERY RAIN MAY THEN LINGER THROUGH TUESDAY AFTERNOON
BEFORE THE FRONT COMPLETELY PUSHES RAIN SOUTH OF THE WI/IL
BORDER AND THE FRONT STALLS OVER NORTHERN IL. WE'LL HAVE A
BREAK WEDNESDAY MORNING, BEFORE THE STATIONARY FRONT WIGGLES
NORTH A BIT, BRINGING SOME RAIN CHANCES FOR WEDNESDAY AFTERNOON
INTO THURSDAY MORNING. DETAILS GET MURKY BEYOND, BUT IT DOES
APPEAR THAT SOME SHOWER CHANCES MAY LINGER INTO FRIDAY, WITH THE
NBM PAINTING BROAD POPS OVER WISCONSIN FROM 35 TO 55% THROUGH
THE DAY.
CMILLER
AVIATION
ISSUED 945 AM CDT SUN SEP 13 2026
VFR CONDITIONS TODAY THROUGH MONDAY, BUT FOG MAY OCCUR IN THE WI
RIVER VALLEY FOR A FEW HOURS EARLY TUE AM. BKN-OVC MID LEVEL
CLOUDS AND A BRIEF PERIOD OF VERY LIGHT RAIN ARE EXPECTED TODAY.
MORE MID LEVEL CLOUDS AND SCATTERED SHOWERS ARE EXPECTED LATE
MON AFTERNOON OVER SOUTH CENTRAL WI.
GEHRING
MARINE
ISSUED 1146 PM CDT SAT SEP 12 2026
LIGHT TO MODERATE NORTHWEST WINDS WILL PREVAIL THROUGH TODAY WITH
OCCASIONAL GUSTS TO 25 KNOTS OVER THE LAKE THIS AFTERNOON.
WINDS EASE TONIGHT AS HIGH PRESSURE MOVES ACROSS THE LAKE INTO
MONDAY MORNING.
WINDS WILL THEN INCREASE AND VEER TO SOUTH-SOUTHWESTERLY MONDAY
AFTERNOON INTO TUESDAY AS LOW PRESSURE DEVELOPS OVER MANITOBA.
GALES APPEAR LIKELY MONDAY NIGHT INTO THE FIRST HALF OF TUESDAY.
A GALE WATCH HAS BEEN ISSUED FOR THE NORTHERN TWO THIRDS OF THE
OPEN WATERS OF LAKE MICHIGAN.
PERIODS OF SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE
DEVELOPING LOW FROM AS EARLY AS MONDAY EVENING INTO TUESDAY. WINDS
WILL TREND NORTHERLY AND WEAKEN BEHIND A COLD FRONT TUESDAY NIGHT
INTO WEDNESDAY.
CMILLER
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ669-LMZ671-LMZ673-LMZ675-LMZ868-LMZ870-LMZ872-LMZ874-
LMZ876...7 PM MONDAY TO 1 PM TUESDAY.
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