NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 222358 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
658 PM CDT Wed Jul 22 2026

.KEY MESSAGES...

- Dry and less humid through the rest of the work week. Muggy
  conditions return this weekend.

- Showers and thunderstorms return to the forecast Saturday
  evening. Rounds of storms, possibly severe, are possible into
  the middle of next week.

&&

.UPDATE...
Issued 700 PM CDT Wed Jul 22 2026

Scattered to broken stratocumulus clouds may linger through a
good portion of the evening, before dissipating overnight. High
pressure will move southeast across the area overnight into
Thursday morning, before shifting to the southeast in the
afternoon and into Thursday night. Dry conditions are expected.

Another round of scattered to mainly broken stratocumulus clouds
are anticipated Thursday afternoon and early evening. Light and
variable to calm winds overnight may lead to some fog in the
Wisconsin River Valley and other low lying areas. A southeast
lake breeze is expected again Thursday afternoon near Lake
Michigan, with light southwest winds inland.

Lows tonight in the lower 50s are expected over most inland
locations, with middle to upper 50s close to Lake Michigan.
Highs Thursday will be mainly in the upper 70s, turning a little
cooler near the lake in the afternoon.

Wood

&&

.SHORT TERM...
Issued 132 PM CDT Wed Jul 22 2026

Rest of Today through Friday:

There were more widespread cumulus clouds and lightly stronger
winds across southern WI today than what was previously
expected, but our forecast highs remain on track at around 74 to
75 (except a degree or two cooler along the lakeshore due to
the lake breeze).

With surface high pressure over southern WI tonight, expect
efficient radiational cooling and another night with lows in the
lower 50s.

Light south-southwest winds are expected Thursday as the high
begins to exit. Inland highs will be in the upper 70s. Expect a
lake breeze to drop the afternoon temps a couple degrees near
the lakeshore.

Steadier southerly winds will develop Friday as a surface
trough approaches from the Northern Plains, but a lake breeze is
still expected. High temperatures will be around 80 with quiet
weather continuing.

Cronce

&&

.LONG TERM...
Issued 132 PM CDT Wed Jul 22 2026

Saturday through Wednesday:

A weak surface trough stemming from a broad upper low and
associated surface low crossing Ontario will sag through WI on
Saturday. This will mainly bring a wind shift from southwest to
west, but the 850-700mb warm air advection and weak surface
convergence (enhanced by the lake breeze) may help trigger a few
showers or thunderstorms in the afternoon and evening. Saturday
high temps will be in the mid 80s with dewpoints creeping back
into the 60s. It will feel warm and humid.

Sunday afternoon and night, and potentially into Monday, look
to bring some more unsettled weather into the area. Overall,
there will be another broad, warm and humid ridge over the
center of the country. This ridge should push into at least the
southwest half of WI on Sunday and bump our highs to around 90
with dewpoints pushing 70 (very warm and humid). Meanwhile, a
mid level shortwave trough is expected to slide across the
US/Canadian border from MN to Lake Superior to Lake Ontario,
coincident with an 850mb baroclinic zone. It looks like
ingredients (moisture, instability, shear) will be in place over
at least central WI Sunday afternoon/night for the potential
for a round of severe storms. The forcing would be the nose of
the low level jet and shortwave trough. There is more
uncertainty for how far south the storms will get Sunday night.

The ridge will hang on over the central U.S. through much of
the next week. Several more shortwave troughs are expected to
track across the Upper Great Lakes from Monday through
Wednesday, so additional rounds of storms (possibly severe) are
likely for central and southern WI. Each round will depend on
how the previous day's storms panned out. This looks to be an
active weather pattern setting up for WI.

Cronce

&&

.AVIATION...
Issued 700 PM CDT Wed Jul 22 2026

Some broken ceilings around 6000 to 8000 feet AGL may linger
into this evening, with scattered clouds mixed in, before
dissipating overnight. High pressure will move southeast across
the area overnight into Thursday morning, before shifting to the
southeast in the afternoon and into Thursday night. Dry
conditions are expected.

Another round of scattered to mainly broken stratocumulus clouds
are anticipated Thursday afternoon and early evening. Any
ceilings should be in the 5000 to 7000 foot AGL range. Light
and variable to calm winds overnight may lead to some fog in the
Wisconsin River Valley and other low lying areas. A southeast
lake breeze is expected again Thursday afternoon near Lake
Michigan, with light southwest winds inland.

Wood

&&

.MARINE...
Issued 132 PM CDT Wed Jul 22 2026

Light and variable winds are expected tonight into Thursday as
high pressure around 30.1 inches crosses Wisconsin and southern
Lake Michigan. Look for southerly winds to develop by Friday as
the high progresses into the northeastern United States. A 29.5
inch low pressure will move quickly from the Canadian Great
Plains toward Quebec Friday through Saturday, maintaining south
to southwest winds over Lake Michigan. The low will attempt to
pull a cold front into the western Great Lakes on Saturday, with
the boundary slowly advancing south across the waters through
Saturday night, which will result in returning thunderstorm
chances. A stationary front is expected to sit across Lake
Michigan through the middle of next week, so there will be
switches between northerly and southerly winds at times. This
front will be the focus for several rounds of thunderstorms,
possibly severe.

Cronce

&&

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

$$

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