NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 242344 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
644 PM CDT Tue Mar 24 2026

.KEY MESSAGES...

- Temperatures continue to warm through Thursday, with highs
  nearing 70 degrees in far southern to southwestern Wisconsin
  on Wednesday and Thursday.

- Chances (mainly 30 to 50 percent) for precipitation returns to
  the area for Thursday. Thunderstorms are possible south of the
  I-94 corridor.

&&

.UPDATE...
Issued 644 PM CDT Tue Mar 24 2026

A mix of mid and high level clouds should help to keep temps
from falling as far as they could tonight given light winds and
relatively low dewpoints. In general, the forecast look on track
for the evening and overnight hours, with no significant update
anticipated.

DDV

&&

.SHORT TERM...
Issued 123 PM CDT Tue Mar 24 2026

Tonight through Wednesday night:

Southwesterly winds will diminish into mid-afternoon, with
continued very dry air across the region. Expecting high
temperatures in the upper 40s to low 50s, even toward Lake
Michigan as southwest winds keep the lake breeze offshore. Late
this afternoon as winds diminish, a brief lake breeze may spread
inland after high temperatures are reached.

Overnight, winds will diminish to light and southeasterly as
high pressure moves into the Northeast U.S. Temperatures will
fall into the mid 30s. Even with the southeasterly tilt to the
wind direction, continued dry air is expected to filter into the
region as Hudson Bay high pressure filters dry northern air into
the mean flow. This will allow for continued dry conditions
through Wednesday as winds shift back to southwesterly ahead of
a weak low pressure system propagating through northern
Wisconsin. Southwest winds are expected to become gusty around
20 mph, while RH values dip to near 30% and perhaps even lower.
Some fire weather concerns may develop if RH values continue to
trend lower. Wind gusts below 30 mph will temper these concerns,
but worth continued awareness. A lake breeze may develop during
the afternoon hours as winds begin to diminish. High
temperatures in the upper 60s are expected in most areas, with a
few spots seeing 70 degrees in far southern to southwestern
Wisconsin and areas near Lake Michigan seeing highs in the low
60s.

MH

&&

.LONG TERM...
Issued 123 PM CDT Tue Mar 24 2026

Thursday through Tuesday:

Synopsis: West-northwest upper level winds will continue to prevail
through the long term period. An absence of any pronounced mid-level
disturbances will thus lead to attendant areas of upper divergence
and surface frontal passages being the primary forcing mechanisms
for precipitation. Two windows for precipitation remain apparent in
forecast guidance, with the first moving in on Thursday & the second
arriving by next Tuesday. Rain will be the favored in each round of
precip, with a few thunderstorms possible along/south of I-94 and US-
18 on Thursday. Widespread hazards are not currently anticipated in
any isolated thunderstorm development on Thursday. A sharp cool down
remains forecast behind a departing cold front Thursday night into
Friday, though temperatures will steadily rebound from the weekend
into early next week.

Thursday: The first precip chances of the period arrive along/behind
a passing cold front. Thermal profiles will be plenty mild enough
through the column to keep precipitation all rain, with precip
chances expected to shut off well in advance of arriving chilly
temperatures behind the front. Have kept precip probabilities capped
at chance (~25-45%) thresholds in the mid-day update, as the
development of precipitation will depend on elevated processes
ongoing above a capped boundary layer. Guidance generally agrees
that said development will be realized during the late morning-early
afternoon hours as a wing of 700-500 mb warm advection shifts across
southern Wisconsin, though a number of different solutions remain
regarding the precise/preferred locations of precip development.
Thus anticipate some north-south sharpening of precip probabilities
as additional CAM guidance comes into range in the coming forecasts,
with likely (~60%+) values becoming necessary as development
location(s) clarify. Forecast soundings do depict some weak MUCAPE
from late morning into the early afternoon along/south of I-94 and
US-18, so have added some slight chance thunder mentions over these
areas in the mid-day update. Apart from some lightning or very small
hail, severe weather hazards are not expected in any thunderstorm
development.

Thursday night through Friday: Continue to expect a brief but
noticeable cool down behind Thursday's cold front. Did blend in some
cooler temperatures with the NBM Thursday night into Friday given a
post-frontal air mass arriving from south-central Canada. Will thus
be a chilly start to the day Friday, with early AM wind chills in
the mid-upper teens remaining on track in this forecast. Still
anticipating high temps in the 5-10 degree below normal range Friday
afternoon, with true temperature moderation not occurring until
Saturday.

Tuesday: The next precip chances arrive along an approaching surface
front & area of upper divergence. Preliminary temperature forecasts
suggest that precip will stay all rain, though trends will be
monitored as this portion of the period draws closer.

Quigley

&&

.AVIATION...
Issued 644 PM CDT Tue Mar 24 2026

Areas of mid and high level clouds will persist through tonight
and into tomorrow, with some clearing possible mid to late
afternoon tomorrow. Winds will generally be light (5 kt or less)
out of the southeast this evening through tonight, with
increasing south to southwest winds expected through the day
tomorrow ahead of an approaching trough. Gusts of 20 to 25 knots
are likely during the afternoon hours. Winds may stay a bit
more southerly from Port Washington to Sheboygan, which may
result in somewhat lighter winds due to the influence of the
chilly lake.

DDV

&&

.MARINE...
Issued 123 PM CDT Tue Mar 24 2026

High pressure of 30.4 inches over the Northeast U.S. and high
pressure of 30.5 inches pressing into Ontario as low pressure
develops in the lee of the central Rockies, keeping winds
southwesterly through this evening. Winds will weaken and shift
to become south-southeasterly tonight as high pressure builds
into the Hudson Bay. Southerly winds then increase into
Wednesday, becoming breezy. Weak low pressure of 29.7 inches will
progress through the Upper Peninsula of Michigan Wednesday
night, shifting winds to southwesterly and allowing them to
diminish. Tuesday morning, a cold front from this low will drag
southward through the lake. Winds behind the front will become
northerly and strong. Gales are becoming more likely Thursday
afternoon through Thursday night for the southern two-thirds of
the lake. Winds gradually diminish through Friday, with high
pressure bringing light and variable winds Friday night.
Saturday, southwesterly winds develop again as high pressure
sits over the Eastern Seaboard and low pressure develops in the
central Plains.

MH

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

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