NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 122003
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
303 PM CDT Fri Jun 12 2026

.KEY MESSAGES...

- Quiet and dry weather expected through tonight and Saturday
  morning.

- A few rounds of scattered thunderstorms expected Saturday
  midday through Saturday night. An isolated storm may become
  strong to severe, with damaging winds and hail the main
  threats.

- Below normal temperatures for early next week.

- Next chances for thunderstorms develop Tuesday and Wednesday
  next week. Too early to tell intensity, but monitoring for
  potential stronger storms, especially on Wednesday.

&&

.SHORT TERM...
Issued 303 PM CDT Fri Jun 12 2026

Tonight through Saturday night:

High temperatures today in the upper 70s to low 80s within dry
westerly flow. No precipitation is expected this afternoon. Winds
will gradually diminish tonight, becoming southwesterly into
Saturday.

As southwesterly flow becomes established over southern Wisconsin
Saturday, expect temperatures to rise into the low to mid-80s,
humidity to increase (dewpoints in the low 60s), and CAPE to
increase to near 1200 J/kg. A weak frontal boundary will set up
across northern to central Wisconsin during the afternoon hours,
with isolated storms expected to develop in the pre-frontal region
in central Wisconsin (currently looking to stretch as far
southward as the I-94 corridor). Storms upstream in Iowa in the
morning hours may progress eastward midday, but confidence is low
at this time. Forcing is not expected to be strong during the
afternoon hours, as the surface front is quite shallow and
oriented west-to-east through the region of southwesterly flow.
Still, if a few storms do develop (20-30% coverage), potential for
a few to become strong to severe with gusty/damaging winds and
hail still exists.

Going into the late afternoon/evening hours, the 500 mb trough
begins to push southward, bringing additional lift to the region.
CAMs still have quite a bit of timing discrepancies for
precipitation development with this shortwave, with faster models
showing development by 4 PM and slower models indicating an
arrival time after 8 PM. Still, the primed environment and global
modeling indicates enough potential to see a broken line of
storms moving southward between 4 and 9 PM (50-70% chances). There
is some indication that storms may linger across far
southeastern Wisconsin into the late overnight hours, bringing
potential for some local flooding across areas that saw
substantial rainfall the past few days (15-20% chance of
additional rainfall over 1 inch south of the I-94 corridor).
Precipitation will exit completely by Sunday morning.

MH

&&

.LONG TERM...
Issued 303 PM CDT Fri Jun 12 2026

Sunday through Friday:

Dry conditions with brisk northwest winds as high pressure builds
into the High Plains on Sunday, with highs only nudging up into
the upper 60s to low 70s. With plenty of sunshine, if winds
diminish during the afternoon some locations may reach the
mid-70s. Lows in the 50s expected overnight. High pressure slowly
slides southeastward into the Lower Mississippi Valley on Monday,
bringing southwesterly return flow to the Great Lakes region.

Meanwhile, a stronger shortwave rotating through the main flow
around a deep trough over the Hudson Bay will begin to progress
southward into the northern Plains. By Tuesday, expect developing
low pressure in the northern Plains to begin to propagate
eastward. This will bring the next chances for storms to southern
Wisconsin within the frontal features of this developing low. At
this time, southern Wisconsin looks to be within the warm sector,
so stronger storms cannot be ruled out. However, intensity will be
dependent on frontal timing as it will largely depend on how
much instability can build across the region.

Low pressure swings back northeastward into the Hudson Bay
Tuesday night into Wednesday, but an additional shortwave
propagating southeastward from the Canadian High Plains will
approach the Upper Midwest on Wednesday. This wave looks to tilt
rapidly northward into Wednesday evening, bringing potential
for additional rounds of strong storms to southern Wisconsin
(PoPs 60-80%). Wrap around precipitation on the back side may
continue to bring chances for rain and storms through Thursday
(15-30% chances), before high pressure builds back into the
Mississippi Valley on Friday.

MH

&&

.AVIATION...
Issued 303 PM CDT Fri Jun 12 2026

VFR conditions through the remainder of today, with westerly
winds gusting to 25 kt. Gusts up to 30 kt are possible for the
next few hours near Lake Michigan. Winds will diminish tonight,
becoming southwesterly and gusty again (20-25 kt) into Saturday
morning. Saturday midday, a broken line of thunderstorms may
progress eastward through the region (~15-30% chances). A better
chance for widespread thunderstorms develops between 4 and 8 PM
on Saturday, especially for MSN to MKE southward.

MH

&&

.MARINE...
Issued 303 PM CDT Fri Jun 12 2026

Low pressure around 29.2 inches in the Hudson Bay will continue
to bring gusty west-southwest winds to Lake Michigan through
this evening. Conditions will remain hazardous for small craft
in the nearshore regions of southern Wisconsin. Winds will
gradually diminish this evening, increasing briefly again
Saturday ahead of a cold front. As the cold front pushes north
to south Saturday night, winds become northwesterly and brisk.
Winds remain northwesterly but diminish through Sunday,
remaining light and variable through Tuesday morning before low
pressure develops in the northern Plains and brings gusty
southwesterly winds to the lake through Wednesday. Winds become
very gusty going into Wednesday evening as low pressure crosses
the northern half of the Lake. A few gales are possible. Winds
then shift to northwesterly as low pressure exits on Thursday.

MH

&&

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

&&

$$

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