013
FXUS63 KMKX 010048
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
748 PM CDT WED SEP 30 2026
KEY MESSAGES
- MODERATE TO HEAVY RAIN WILL SPREAD INTO SOUTHERN WISCONSIN
LATE TONIGHT INTO THURSDAY. ISOLATED THUNDESTORMS MAY OCCUR.
1.5 TO 2.25 INCHES OF RAIN IS FORECAST THROUGH THURSDAY, BUT
MUCH LESS TOWARD CENTRAL WI. URBAN AND SMALL STREAM FLOODING
WILL BE POSSIBLE WHERE LOCALLY HIGHER RAIN AMOUNTS OCCUR.
OTHERWISE, RISES IN RIVERS AND LOW LYING AREAS ARE EXPECTED.
UPDATE
ISSUED 747 PM CDT WED SEP 30 2026
THE FORECAST FOR WIDESPREAD MDT TO HEAVY RAINFALL REMAINS ON
TRACK FOR LATE TNT-THU AM. A WAVE OF LOW PRESSURE OVER CENTRAL
KS WILL TRACK TO ERN IA BY 12Z THU, WHILE A SHORTWAVE TROUGH
OVER NE INTO NW IA APPROACHES SRN WI DURING THIS TIME. THE NOSE
OF A SWLY LOW LEVEL JET OF 40-45 KT WILL SET UP OVER FAR SRN WI
DURING THIS TIME. DEEP, SLOPING FRONTOGENESIS WILL DEVELOP
ACROSS THE REGION AS THE LOW AND AFOREMENTIONED FEATURES SHIFT
ACROSS SRN WI INTO LOWER MI ON THU. THE STRONG LIFT WILL OCCUR
WITHIN A SATURATED TROPOSPHERE AND PWATS AROUND 2 INCHES. THUS
HIGH PRECIPITATION EFFICIENCY IS EXPECTED. THE MEAN FLOW WILL BE
FAIRLY FAST, BUT SEVERAL HOURS OF MDT TO HEAVY RAIN WILL STILL
OCCUR FOR MOST LOCATIONS. RAINFALL AMOUNTS OF 1.5-2.25 INCHES
ARE FORECAST WITH LOCALLY MORE. URBAN AND SMALL STREAM FLOODING
WILL BE POSSIBLE WHERE THOSE LOCALLY HIGHER AMOUNTS OCCUR.
RAINFALL AMOUNTS TOWARD CENTRAL WI WILL BE MUCH LESS. THE
WIDESPREAD RAIN WILL CONTINUE OVER SE WI FOR THE AFTERNOON
FOLLOWED BY COOLING AND DRYING FROM THE NORTH AFTERWARD. SKIES
WILL GRADUALLY CLEAR THU NT ON NLY WINDS AND COLD AND DRY AIR
ADVECTION. TEMPS WILL REMAIN IN THE 60S TNT AND TOMORROW THEN
FALL INTO THE MIDDLE 40S TO LOWER 50S BY SUNRISE FRIDAY.
GEHRING
SHORT TERM
ISSUED 248 PM CDT WED SEP 30 2026
TONIGHT THROUGH THURSDAY NIGHT:
THE FIRST ROUND OF RAIN HAS PUSHED OUT OF THE AREA, WITH
LINGERING LIGHT DRIZZLE AND SOME FOG IN PARTS OF THE AREA UNDER
LOW STRATUS CLOUDS. THIS SHOULD LINGER INTO THIS EVENING, UNTIL
THE NEXT ORGANIZED AREA OF RAIN SHOWERS MOVES NORTHEAST INTO
THE AREA. CAMS SUGGEST THIS ARRIVAL WILL BE SOUTHWEST TO
NORTHEAST ACROSS THE AREA FROM THE MIDDLE TO LATE EVENING HOURS,
AS THE LOW LEVEL JET NOSE REORIENTS ITSELF TOWARD THE AREA FROM
THE SOUTH SOUTHWEST. THE 850 MB TROUGH AXIS WILL ALSO SHIFT
THROUGH THE AREA LATER TONIGHT INTO THURSDAY MORNING, PROVIDING
SOME ADDED UPWARD VERTICAL MOTION.
THESE FEATURES SHOULD CONTINUE TO DRIVE THE MODERATE TO HEAVY
RAIN OVERNIGHT INTO THURSDAY MORNING. THIS ACTIVITY SHOULD
GRADUALLY PUSH SOUTHEASTWARD IN THE AFTERNOON AND OUT OF THE
AREA THURSDAY EVENING, AS A COLD FRONT PUSHES SOUTHEAST AND
BRINGS DRIER AIR INTO THE AREA.
FORECAST SOUNDINGS CONTINUE TO SHOW THE DEEP AND SATURATED
MOIST ADIABATIC PROFILES ACROSS THE AREA LATER TONIGHT INTO
THURSDAY, WITH PRECIPITABLE WATER VALUES IN THE 1.80 TO 2.00
INCH RANGE. ISOLATED THUNDERSTORMS MAY OCCUR AS WELL DURING THIS
PERIOD, AS A LITTLE ELEVATED CAPE (250 TO 350 J/KG) MAY
DEVELOP. THIS COULD LEAD TO LOCALLY HIGHER RAINFALL AMOUNTS.
OVERALL, RAINFALL TOTALS WITH THIS NEXT ROUND SHOULD GENERALLY
BE IN THE 1 TO 3 INCH RANGE, HIGHEST TOWARD THE ILLINOIS BORDER
AREAS.
GIVEN THE LONGER DURATION NATURE OF THE RAIN, AND THE LACK OF
ORGANIZED CONVECTION, WOULD EXPECT MORE OF A SOAKING RAIN WITH
THE IMPACTS BEING SOME RIVER RISES AND PONDING OF WATER IN LOW
AREAS. WILL CONTINUE TO MESSAGE THIS AS WELL.
THE DIURNAL TEMPERATURE RANGE WILL BE SMALL INTO THURSDAY, WITH
LOWS TONIGHT REMAINING IN THE LOWER TO MIDDLE 60S AND HIGHS
THURSDAY IN THE UPPER 60S. ONCE THE COLD FRONT MOVES SOUTHEAST
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING, NORTHWEST WINDS
BEHIND IT SHOULD BRING COOLER LOWS IN THE MIDDLE TO UPPER 40S
FOR THURSDAY NIGHT.
A HIGH SWIM RISK REMAINS FOR THE LAKE MICHIGAN BEACHES IN
SHEBOYGAN COUNTY INTO EARLY THIS EVENING. INCREASING SOUTH WINDS
SHOULD BRING WAVES OF 3 TO 5 FEET IN THESE AREAS. STAY OUT OF
THE WATER, AND AWAY FROM DANGEROUS AREAS LIKE PIERS AND
BREAKWALLS.
WOOD
LONG TERM
ISSUED 248 PM CDT WED SEP 30 2026
FRIDAY THROUGH WEDNESDAY:
SURFACE HIGH PRESSURE FROM THE NORTHERN PLAINS WILL FINALLY
PUSH INTO WISCONSIN BY FRIDAY, IN THE WAKE OF AN UPPER TROUGH
THAT SWINGS ACROSS LAKE SUPERIOR. NORTHERLY WINDS UP TO 20 MPH
IN THE MORNING WILL DIMINISH TO 15 MPH BY LATE AFTERNOON. EXPECT
A SUNNY DAY WITH HIGHS IN THE LOWER TO MID 60S, WHICH IS
SLIGHTLY BELOW NORMAL. LOWS FRI NIGHT WILL DIP DOWN TO AROUND 40
FOR MOST OF SOUTHERN WISCONSIN, BUT REMAIN IN THE MID/UPPER 40S
RIGHT ALONG THE LAKE MICHIGAN SHORELINE.
FOR SATURDAY, A WEAK TROUGH WILL APPROACH WISCONSIN FROM THE
DAKOTAS. THIS WILL GIVE US A WIND SWITCH TO THE SOUTH WITH THE
DEPARTING HIGH, AND SOME INCREASING MIDDLE AND HIGH CLOUDS,
ESPECIALLY TOWARD EVENING. HIGHS SATURDAY WILL BE IN THE MIDDLE
60S, ALTHOUGH COOLER BY LAKE MICHIGAN DUE TO A SOUTHEAST
COMPONENT TO THE WIND. LIGHT RAIN SHOWERS ASSOCIATED WITH THE
PASSAGE OF A SURFACE AND UPPER LEVEL TROUGH SHOULD REMAIN NORTH
OF SOUTHERN WISCONSIN SATURDAY AFTERNOON AND NIGHT, DUE TO LOW
LEVEL DRY AIR, ALTHOUGH CANNOT RULE OUT A FEW SPRINKLES. LOWS
SATURDAY NIGHT WILL BE IN THE UPPER 40S.
EXPECT SUNSHINE AND A NORTHWEST BREEZE SUNDAY, WITH HIGHS IN
THE UPPER 60S. WE WILL HAVE A COUPLE OF COOLER NIGHTS SUNDAY AND
MONDAY NIGHT, WITH HIGH PRESSURE DRIFTING THROUGH THE UPPER
GREAT LAKES REGION. WITH DEWPOINTS EXPECTED TO BE CLOSE TO THE
LOW TEMPERATURE VALUES IN THE UPPER 30S TO AROUND 40 EACH
NIGHT, AREAS OF FOG MAY DEVELOP.
WE WILL HAVE A WARMING TREND TUESDAY AND WEDNESDAY, WITH
WEDNESDAY HIGHS AROUND 70. ANOTHER UPPER TROUGH IS EXPECTED TO
CROSS ONTARIO WEDNESDAY. THE LATEST RUN OF THE GFS HAS A MORE
AMPLIFIED TROUGH THAN THE ECMWF, AND ENSEMBLES SUPPORT THIS
DIFFERENCE AS WELL. IF THE TROUGH IS MORE AMPLIFIED, THE CHANCE
OF RAIN SHOWERS WILL INCREASE FOR SOUTHERN WISCONSIN.
CRONCE
AVIATION
ISSUED 747 PM CDT WED SEP 30 2026
CIGS WELL BELOW 1 KFT WILL DEVELOP THIS EVENING AND LAST THROUGH
THU AM, THEN LINGERING INTO THE AFTERNOON OVER SE WI. VSBYS OF
2-4SM VIA BR AND DRIZZLE WILL PREVAIL THIS EVENING THEN DROPPING
TO 1-2SM VIA BR AND WIDESPREAD RAINFALL DURING THE OVERNIGHT AND
MUCH OF THU AM. LOCAL 1/2SM FG WILL BE POSSIBLE DURING THIS
TIME. THE WIDESPREAD RAIN WILL CONTINUE OVER SE WI DURING THE
AFTERNOON WITH LOW CIGS AND VSBYS CONTINUING. CIGS AND VSBYS WILL
THEN RISE TO MVFR THEN VFR FROM NW TO SE ACROSS SRN WI FROM
LATE AFTERNOON INTO THE EVENING.
GEHRING
MARINE
ISSUED 747 PM CDT WED SEP 30 2026
THE SMALL CRAFT ADVISORY HAS BEEN CANCELLED THIS EVENING FROM
PORT WASHINGTON TO SHEBOYGAN AS WINDS AND WAVES ARE SUBSIDING.
SOUTH WINDS WILL GRADUALLY BECOME SOUTHWEST AND EASE TONIGHT
INTO THURSDAY MORNING, AS A COLD FRONT APPROACHES FROM THE
NORTHERN PLAINS. EXPECT MODEST NORTHWEST WINDS IN THE WAKE OF
THE FRONT BY THURSDAY EVENING, WITH NORTH TO NORTHWEST WINDS
THURSDAY NIGHT INTO FRIDAY. STRONG HIGH PRESSURE AROUND 30.4
INCHES WILL OVERSPREAD THE GREAT LAKES FRIDAY NIGHT. THIS SHOULD
BRING LIGHTER WINDS TO THE LAKE FRIDAY NIGHT INTO SATURDAY.
A FAST-MOVING LOW PRESSURE SYSTEM AROUND 29.8 INCHES SHOULD
MOVE ACROSS OR NORTH OF LAKE SUPERIOR SATURDAY NIGHT, WITH HIGH
PRESSURE AROUND 30.4 INCHES MOVING SOUTHEAST INTO THE REGION BY
EARLY NEXT WEEK. SOUTH TO SOUTHWEST WINDS SATURDAY NIGHT SHOULD
VEER NORTHWEST TO NORTH SUNDAY INTO MONDAY ACROSS LAKE
MICHIGAN.
WOOD/GEHRING
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...NONE.
VISIT US AT WEATHER.GOV/MILWAUKEE
FOLLOW US ON FACEBOOK, X, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSMILWAUKEE
WWW.X.COM/NWSMILWAUKEE
WWW.YOUTUBE.COM/NWSMILWAUKEE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page