NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 231041
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
541 AM CDT Sat May 23 2026

.KEY MESSAGES...

- Expect a gradual warming trend through early next week with
  highs in the 80s by Memorial Day.

- 40-50% percent chances for showers late this afternoon over
  south central WI, slowly spreading east across S WI through
  the night. Isolated thunderstorms are possible.


&&

.UPDATE...
Issued 541 AM CDT Sat May 23 2026

Stratus clouds have moved into ern WI, but expect the light
rain to remain over the lake as the associated shortwave trough
and low pressure from IN to Ohio moves newd today. The stratus
should become scattered by early afternoon. Farther to the west
broken cumulus development is expected by late afternoon as a
weak north to south sfc trough approaches. The shortwave trough
currently over CO will aid in driving the sfc trough across srn
WI tnt as it approaches. Very marginal MUCAPE will be present as
dewpoints increase well into the 50s along with PWATs of 1.3
inches. 40-50 percent chances for showers and isolated storms
are forecast. High temps will range from the upper 50s at the
Lake MI shoreline to lower 70s well inland.

The shortwave trough passage will occur Sun AM with a few
lingering showers possible over far ern WI. Stratus and patchy
fog will likely develop early in the morning but dissipate by
late morning as subsidence and heating ensues. High temps will
range from the upper 60s at the Lake MI shoreline to upper 70s
well inland.

Gehring

&&

.SHORT TERM...
Issued 1058 PM CDT Fri May 22 2026

Tonight through Sunday:

Surface low pressure will approach the area from the southwest
tonight, passing by to the southeast on Saturday. Models have
continued to trend drier for southern Wisconsin with this
system, with maybe a little light rain or sprinkles brushing the
southeast later tonight into early Saturday. Clouds will hang
around yet another day on Saturday as the low moves through the
region and a shortwave approaches from the west. Trended the
forecast towards the cooler end of model guidance for highs Sat
given the clouds, though temps should still return to around
normal values for late May away from Lake Michigan. Onshore
winds will keep it a bit cooler near the lake.

Kept a chance for showers and a few rumbles of thunder late this
afternoon into tonight as the shortwave slowly slides through
the area. Upstream showers/storms this evening along with higher
dewpoints over Iowa are boosting confidence a bit in the
shower/storm chances later tomorrow.

Skies are expected to clear west to east on Sunday, with above
normal temps likely under a good amount of sunshine in the
afternoon.

A high swim risk continues into late tonight for all southern
Wisconsin lakeshore counties. Life threatening waves and
currents are expected.

DDV

&&

.LONG TERM...
Issued 1058 PM CDT Fri May 22 2026

Monday through Friday:

Monday looks mainly dry under surface high pressure and as
upper level riding begins to build in from the west. There's a
small chance though that an area of showers/storms comes through
the top of the ridge on Monday, but confidence in this scenario
is decreasing. Above normal temps are expected for Memorial Day
along with somewhat higher dewpoints as well.

Warm temps and higher dewpoints will persist into mid-week,
with some instability suggesting the potential for more
shower/storm chances if a wave or two pushes through the area.
It then looks cooler and drier late week as surface high
pressure builds in from the north.

DDV

&&

.AVIATION...
Issued 541 AM CDT Sat May 23 2026

MVFR Cigs over ern WI this morning becoming scattered this
afternoon. Scattered showers and isolated thunderstorms will
then slowly move into south central WI late this afternoon, then
slowly east through the night. Areas to widespread MVFR Cigs are
expected to redevelop from late this evening through Sunday
morning. Patchy light fog is also possible.

Gehring

&&

.MARINE...
Issued 541 AM CDT Sat May 23 2026

High pressure around 30.5 inches centered over Quebec will slowly
move across the New England coast later today and tonight. Meanwhile,
low pressure of 29.8 inches over the western Ohio Valley will move
to Lake Huron and southern Ontario for tonight. Modest to breezy
easterly winds will continue into this evening over far northern
Lake Michigan. Elsewhere, light to modest east northeast winds
will turn northerly for this afternoon. The light winds will then
gradually turn southerly late tonight into Sunday morning across
all of Lake Michigan. Light to modest southerly winds are then
likely for Sunday through Tuesday.

Gehring

&&

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

$$

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