645
FXUS63 KMKX 180850
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
350 AM CDT THU SEP 18 2025
KEY MESSAGES
- CHANCES (25% TO 35%) FOR SCATTERED STORMS FROM A MONROE /
MADISON / FOND DU LAC LINE THRU THURSDAY.
- SHOWER AND THUNDERSTORM CHANCES EDGE EASTWARD INTO FRIDAY,
WITH MORE WIDESPREAD 20-50% CHANCES ARRIVING THIS WEEKEND.
- SMALL CRAFT ADVISORY CRITERIA WAVES MAY START FRIDAY NIGHT AND
LINGER INTO SATURDAY AS GUSTY WIND COME AROUND TO
SOUTHEASTERLY OVER THE LAKE.
SHORT TERM
ISSUED 347 AM CDT THU SEP 18 2025
TODAY THROUGH FRIDAY:
PATCHY GROUND FOG WILL BE POSSIBLE AGAIN THIS MORNING, WITH
AREAS DISSIPATING AFTER DAWN. THEN, PARTLY SUNNY SKIES ARE
EXPECTED THROUGH MOST OF TODAY, WITH HIGHS GENERALLY IN THE
80S, SAVE FOR AREAS ALONG THE IMMEDIATE LAKE MICHIGAN SHORELINE.
A LOBE OF THE UPPER LOW OVER THE NORTHERN PLAINS IS EXPECTED TO
DIG INTO IOWA/EASTERN NEBRASKA THIS AFTERNOON AND EVENING,
CAUSING AREAS OF THUNDERSTORMS OVER IOWA. SOME OF THESE
THUNDERSTORMS MAY MOVE INTO AREAS ALONG AND WEST OF A
MONROE/MADISON/FOND DU LAC LINE DURING THE LATE AFTERNOON INTO
THE EVENING.
SHOWER AND STORM CHANCES THEN SLOWLY BEGIN TO PROGRESS EAST ON
FRIDAY AS THE SURFACE LOW FINALLY MEANDERS INTO WESTERN MN/IA.
BETTER CHANCES MOVE IN (30 TO 50%) MOVE IN WEST OF THE LAKESHORE
FRIDAY AFTERNOON.
CMILLER
LONG TERM
ISSUED 323 AM CDT THU SEP 18 2025
FRIDAY NIGHT THROUGH WEDNESDAY:
LOW PRESSURE WILL FINALLY EJECT OUT OF THE CENTRAL PLAINS FRIDAY
NIGHT, PUSHING NORTHEASTWARD INTO MANITOBA AND SLOWLY DRAGGING A
FRONT THROUGH SOUTHERN WISCONSIN. HIGH PRESSURE CONTINUING TO SIT
JUST TO THE EAST OVER QUEBEC AND ONTARIO WILL RESULT IN A
PROLONGED PERIOD OF ON-AND-OFF SHOWERS AND THUNDERSTORMS THROUGH
THE WEEKEND (30 TO 50 PERCENT CHANCE IN ANY GIVEN TIME FRAME) AS
THE FRONT STALLS OVER SOUTHERN WISCONSIN. EXPECT ALMOST ALL AREAS
TO SEE SOME RAINFALL OVER THE COURSE OF THE WHOLE WEEKEND.
AS HIGH PRESSURE SLOWLY EXITS INTO MONDAY, THE FRONT BEGINS TO
SHIFT EASTWARD OUT OF THE AREA. HOWEVER, A SHORTWAVE TRAVELING
SOUTHWARD ALONG THE ROCKIES THROUGH THE WEEKEND WILL CATCH THE
SOUTHERN TAIL OF THIS FRONT AND SPIN ITS WAY INTO A SURFACE LOW
PRESSURE SYSTEM MONDAY INTO TUESDAY, BRINGING ADDITIONAL RAINFALL
CHANCES TO THE GREAT LAKES REGION. HOWEVER, EXACTLY HOW THIS
SHORTWAVE WILL PHASE WITH THE TROUGH AND THEREFORE HOW MUCH LIFT
WILL BE BROUGHT TO SOUTHERN WISCONSIN REMAINS IN QUESTION. LOWERED
CONFIDENCE RESULTS IN LOWER PRECIPITATION CHANCES (15 TO 30
PERCENT) ACROSS THE ENTIRE MONDAY TO TUESDAY TIMEFRAME. MODEL
DIVERGENCE BECOMES EVEN MORE APPARENT GOING INTO WEDNESDAY, WITH
SOLUTIONS FOR LOW PRESSURE PLACEMENT RANGING FROM THE GREAT LAKES
(GFS) TO THE LOWER MISSISSIPPI VALLEY (ECMWF) TO EASTERN ONTARIO
(CANADIAN). KEPT NBM SOLUTION FOR THIS TIME FRAME.
MH
AVIATION
ISSUED 325 AM CDT THU SEP 18 2025
AFTER SOME PATCHY MORNING FOG, AND SCATTERED LOW VFR STRATUS, A MIX
OF SUN AND CLOUDS SHOULD OCCUR TODAY WITH CONTINUING VFR. THERE
ARE SLIGHT CHANGES FOR SCATTERED SHOWERS AND STORMS TO OCCUR
ALONG AND WEST OF A KMRJ TO KMSN TO KFLD LINE LATER THIS
AFTERNOON INTO THE EVENING. WINDS WILL BE LIGHT AND VARIABLE
THIS MORNING, AND REMAIN LIGHT INTO THIS EVENING WITH NORTHEAST
WINDS ALONG THE LAKESHORE, AND EAST TO SOUTHEAST WINDS INLAND.
CMILLER
MARINE
ISSUED 324 AM CDT THU SEP 18 2025
WINDS REMAIN LIGHT AND VARIABLE OVER THE SOUTHERN HALF OF THE LAKE,
WITH A LIGHT NORTHEAST WIND DEVELOPING OVER THE NORTHERN HALF OF
THE LAKE IN RESPONSE TO A WEAK BACKDOOR COLD FRONT THROUGH THIS
MORNING. THIS FRONT SAGS SOUTHWARD ACROSS THE REST OF THE LAKE BY
THIS AFTERNOON, BRINGING STEADY NORTH WINDS.
LIGHT TO MODERATE NORTHEAST WINDS ARE THEN EXPECTED INTO FRIDAY,
BECOMING BREEZY AND VEERING SOUTHEAST FRIDAY NIGHT THROUGH
SATURDAY MORNING AS THE HIGH PRESSURE STRENGTHENS AND
APPROACHES SOUTHERN ONTARIO AND QUEBEC AND AS LOW PRESSURE
MOVES INTO THE DAKOTAS AND MINNESOTA. ON AND OFF THUNDERSTORMS
ARE EXPECTED FRIDAY NIGHT THROUGH SUNDAY.
CMILLER
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...NONE.
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