NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 260524
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1224 AM CDT Fri Jun 26 2026

.KEY MESSAGES...

- Hot and humid conditions are expected next week, possibly
  hitting Heat Advisory criteria at times Monday through
  Thursday.

- There will be a chance for storms Saturday night into Sunday
  and again later Tuesday through Thursday.

&&

.SHORT TERM...
Issued 1224 AM CDT Fri Jun 26 2026

Overnight through Sunday:

Patchy fog is possible overnight, primarily toward Lake
Michigan. Light to modest easterly winds will persist through
Saturday. This will keep lakeshore areas cooler than inland, and
also below normal for a couple more days. Look for plenty of
cloud cover across southern WI today as low pressure (and
associated showers/storms) tracks across IL and IN. The precip
will remain south of the WI/IL border.

There is still a chance (30-45%) of showers and maybe a rumble
of thunder Saturday night into Sunday morning as a weak "wing"
of mid level warm air advection lifts through WI. The chance for
thunder is low because of the strongly capped environment and
weak mid level lapse rates. This is our first push of warmer
and more humid air into the region, but lakeshore max temps
(mid- upper 70s) will remain cooler than inland (mid 80s) due to
steady southeast winds.

Cronce

&&

.LONG TERM...
Issued 1224 AM CDT Fri Jun 26 2026

Sunday night through Thursday:

The upper level ridge will settle over the Mid Mississippi River
Valley by Monday morning. Some overnight showers are possible
(20% chance) in east central WI. Very warm and humid air will
work into southern WI on Monday and stick around through the
holiday weekend. High temperatures will be in the lower to mid
90s each day, and dewpoints will likely reach 70 (not sure how
far above 70, as models seem to be overdoing this element). The
NAEFS (ensemble) is showing that this warm of temps is in the
99th percentile compared to climate, has a one-day-
every-10-years return interval, and is around 2 standard
deviations higher than normal.

This is going to be a prolonged period of hot and humid
conditions that will quickly become dangerous for those without
air conditioning, especially since overnight temps will remain
in the 70s (upper 70s at times). Heat advisories will likely be
needed.

Expect chances for thunderstorms at times during this heat wave,
although the ability to predict exactly when and where storms
could develop will be limited to the day before. This is because
storms will likely develop in the Northern Plains, MN and
northwest WI areas and then potentially roll into central or
southern WI overnight into the next morning. Any of these storm
complexes could limit our daily high temperatures and offer a
temporary reprieve from the extreme heat, but not the humidity.

Cronce

&&

.AVIATION...
Issued 1224 AM CDT Fri Jun 26 2026

Mid and high level clouds will increase overnight into Friday as
low pressure and associated precip tracks across MO/IL/IN.
Cloud bases should lower to around 5000ft as the system passes
by during the day, then diminish overnight. Light-modest
easterly winds are expected today.

Cronce

&&

.MARINE...
Issued 1224 AM CDT Fri Jun 26 2026

High pressure over Ontario and the western Great Lakes will
dominate today through Saturday with light north to northeast
winds. Sunday, low pressure will deepen over the Central
Plains, bringing breezy southeasterly winds to the lake. Winds
then turn southerly and strengthen Monday (not quite gales) as
low pressure exits into the Canadian Prairies. Breezy southerly
winds will persist for most of next week. A Small Craft
Advisory will likely be needed.

Cronce

&&

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

$$

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