NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 251959
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
259 PM CDT Wed Mar 25 2026

.KEY MESSAGES...

- Highs in the upper 60s to low 70s across the majority of
  southern Wisconsin this afternoon, with gusty southwest winds
  between 25 and 30 mph.

- A cold front will drop through the area Thursday, bringing
  rain and much cooler temperatures. A few rumbles of thunder
  are possible, mainly south of I-94. An isolated thunderstorm
  cell is possible along the Illinois/Wisconsin border.

- Cooler conditions will persist Friday, with scattered
  rain/snow showers possible from central to southeastern
  Wisconsin (15-25% chance).

- Return to warmer temperatures for the weekend.

&&

.SHORT TERM...
Issued 300 PM CDT Wed Mar 25 2026

Tonight through Thursday night:

Clouds have largely cleared out across the region, with only a few
areas of cloud cover remaining. Therefore expecting temperatures
to reach the forecasted highs in the low 70s across southwestern
Wisconsin and in the upper 60s in south central Wisconsin.
Additional cloud cover will move in this evening. Gusty
southwesterly winds between 25 and 30 mph are expected to
continue through sunset before diminishing. Winds will weaken
overnight and become light and variable as low pressure deepens in
the central Plains. Overnight lows are expected to be in the 40s.

As low pressure ejects into Iowa and strong high pressure builds
into Ontario on Thursday morning, expect a cold front to slide
down Lake Michigan into southern Wisconsin by midday. This front
is expected to set off a round of rain and a few embedded
thunderstorms. Depending on the timing of the front and pre-
frontal convection (definitely in question as dewpoints are only
expected to be in the 40s), temperatures in the low to mid 60s are
possible across far southern Wisconsin. However, a more likely
solution is that the CAA regime originating from Canada and Lake
Michigan slides underneath the warmer airmass and produces
elevated convection with temperatures in the upper 50s before
falling through the afternoon. Cannot rule out an isolated
stronger storm, but have strong confidence in the elevated nature
of any convection that does develop. Hail would be the only
expected threat.

Storms will transition to rain showers Thursday evening, tapering
off overnight. Northerly winds will remain gusty, with expected
gusts between 30 and 35 mph and a few gusts up to 40 mph near
Lake Michigan. Temperatures will fall into the low to mid 20s.
Winds slowly diminish into the early morning hours Friday.

MH

&&

.LONG TERM...
Issued 300 PM CDT Wed Mar 25 2026

Friday through Wednesday:

Northerly winds will shift northwesterly into Friday and diminish,
with temperatures rising back into the 40s. A 500 mb shortwave
propagating southward through the region will bring light,
scattered rain and snow showers (15-25% chance) to primarily
central to southeastern Wisconsin during the afternoon and evening
hours, with little to no snow accumulations expected. Overnight
lows in the low 20s are expected under building high pressure.

High pressure continues to propagate eastward into Saturday as
broad low pressure develops in the lee of the central to northern
Rockies. This will also bring a return to southwesterly surface
flow and allow for temperatures to recover to around 50 degrees.

Southwesterly winds continue to increase into Sunday as a weak low
propagates through Canada. This will continue to build
southeastern U.S. ridging through early next week, leading to
warm frontogenesis across the Upper Midwest, and increasing
chances for rain and a few thunderstorms (PoPs ~50% Monday night
into Tuesday). Low pressure finally ejects into the central
Plains Tuesday night. Exact track of this low remains in
question at this time, with a strong Canadian high suppressing
its northward trajectory while it taps into Gulf moisture. Will
bear watching in future forecast updates as a more northerly
track to the low could result in widespread organized
thunderstorms going into Wednesday.

MH

&&

.AVIATION...
Issued 300 PM CDT Wed Mar 25 2026

VFR conditions expected to continue throughout this afternoon and
tonight. Expect southwesterly wind gusts 20 to 25 kt through this
afternoon, diminishing tonight. Winds will become light and
variable tonight (around 5 kt), then will turn to northeasterly
through Thursday morning as a cold front slides southwestward
through the morning hours. Rain and a few embedded thunderstorms
are expected along this front, with rain lingering after
thunderstorms end. The best chances for thunderstorm activity is
in far southern Wisconsin (JVL/ENW), and the chance is still low
(~20-30%). Ceilings will also fall into MVFR along the edges of
the front, falling to IFR into Thursday evening.

MH

&&

.MARINE...
Issued 300 PM CDT Wed Mar 25 2026

Southwesterly winds will continue through this evening, slowly
diminishing to light and variable tonight under a brief wave of
weak low pressure. A Small Craft Advisory is in effect for the
southern Wisconsin nearshore zones through 7 PM CDT for gusty
winds. Low pressure of 29.5 inches developing in the central
Plains Thursday will bring a wind shift of northerly as strong
high pressure of 30.7 inches builds over the Canadian Prairies.
Increasing pressure gradient is expected to bring gales to the
southern two thirds of the open waters Thursday afternoon
through Thursday night. Winds will gradually diminish into
Friday, as high pressure builds into the northern Plains and
Upper Mississippi Valley. Light and variable winds are expected
into Saturday as high pressure moves east through the Ohio
Valley. Winds return to southerly as high pressure exits Sunday,
with southerly winds continuing through Monday.

MH

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM
     Wednesday.

     Gale Warning...LMZ644-LMZ645-LMZ646...7 PM Thursday to 5 AM
     Friday.

     Gale Warning...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-
     LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-
     LMZ876-LMZ878...5 PM Thursday to 5 AM Friday.

&&

$$

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