NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 230002
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
702 PM CDT Wed Apr 22 2026

.KEY MESSAGES...

- Well above-normal temperatures continue through Thursday.

- Periods of showers and storms (60-90 percent chance) expected
  late Thursday evening into Friday. There is a Marginal Risk
  for severe storms mainly for damaging winds.

- Showers and thunderstorms return late Sunday night through
  Monday night.

&&

.UPDATE...
Issued 702 PM CDT Wed Apr 22 2026

Dry and quiet conditions continue this evening across Wisconsin.
Southeast winds this evening will weaken overnight and should
turn to southerly Thursday as a warm front slowly creeps north.
The associated low pressure system and upper level PVA remain to
the west in the northern and central Plains. This system will
approach the Great Lakes Region for Thursday evening into Friday
morning. No major changes to the forecast.

Patterson

&&

.SHORT TERM...
Issued 250 PM CDT Wed Apr 22 2026

Tonight through Thursday night:

Cyclogenesis will continue from the high plains of MT this
afternoon into srn Manitoba on Thu, while downstream upper
ridging is expected over WI. Increasing sly winds can be
expected as a n-s sfc trough and cold front moves ewd across
the Great Plains. High temps are still expected to be near 80F
for Thu afternoon.

For late Thu evening and Fri a shortwave trough will lift from
the central Great Plains into WI, while the cold front slowly
passes. Thus 60-90 percent chances for showers and scattered
storms are forecast. There is a Marginal Risk for severe storms
Thu evening into the overnight as a MCS will likely track from
the MS River into south central WI. Despite relatively weak
effective shear, 0-3 km shear is 25-30 kts and cannot rule out
bowing structures and some potential for meso-vortices. The CAMS
do show a weakening trend as it moves into se WI during the
early morning hours, which may be due to the gust front
accelerating ahead of the main line of convection. In addition,
rainfall totals over an inch will be possible over south
central WI, and cannot rule out urban and small stream
flooding. The models then differ on the timing of the cold
frontal passage on Fri, but will count on some redevelopment
into the early afternoon.

Gehring

&&

.LONG TERM...
Issued 250 PM CDT Wed Apr 22 2026

Saturday through Wednesday:

A weak high pressure area will then pass on Sat followed by
increasing sely winds and warm advection for Sunday ahead of
cyclogenesis over the central Great Plains. The low pressure
area and associated shortwave trough is then expected to lift
newd into WI on Mon, with another round (60-80 percent) of
showers and storms. At this time, widespread rainfall totals of
an inch are reasonable. Quiet weather will then return Tue-Wed
with temps around normal.

Gehring

&&

.AVIATION...
Issued 702 PM CDT Wed Apr 22 2026

Mostly VFR conditions are expected through the period. Southwest
winds inland and northeasterly along Lake Michigan will diminish
overnight into Thursday morning. Winds will then turn due
southerly and become breezy Thursday with gusts around 25 kts
(30 MPH). Terminals along Lake Michigan are likely to keep that
onshore component to the winds making it south to
southeasterly. Winds will weaken again Thursday night and then
turn to northwesterly behind a cold front Friday morning/early
afternoon.

As the cold front approaches Wisconsin Thursday evening into
Thursday night, clouds will increase from west to east. The
potential for any lower ceilings (MVFR to IFR) will depend on
how quickly rain/storms move in ahead of the cold front. Rain
and storms are expected to move in near the end of the TAF
period. This system has been trending a bit slower overtimes so
this could be pushed back a couple hours yet (closer to
midnight). Rain and storms are expected to become weaker and
more scattered to isolated as they move east. Lightning,
damaging winds and heavy rain are the main concerns with any
storms overnight into Friday morning.

Patterson

&&

.MARINE...
Issued 250 PM CDT Wed Apr 22 2026

High pressure will shift from the northern Great Lakes to the
lower Great Lakes into this evening. Light northerly winds are
expected with areas of fog over far southern Lake Michigan.

Winds veer southeast and accelerate late tonight through Friday
morning as 29.2 inch low pressure develops over the northern Great
Plains and slowly tracks eastward. Some 30 kt easterly winds may
occur over the northern tip of the lake Thursday night and Friday.

The low will pull a cold front across Lake Michigan Friday
afternoon and evening, resulting in a breezy north-northwest wind
shift. Showers and thunderstorms are expected late Thursday night
through Friday, both ahead of and along the front. Severe weather
is not anticipated at this time.

Northerly winds will continue through the weekend across Lake
Michigan. 29.4 inch low pressure is forecast to track
northeastward from the central Great Plains (Sunday night) near or
over Lake Michigan (Monday night), with gusty east to southeast
winds ahead of its arrival and gusty west or northwest winds
behind it (into Tuesday). Not seeing widespread gale potential
with this system, though trends will be monitored.

A Small Craft Advisory may be needed Thursday night into Friday
morning north of Port Washington for building waves. Additional
Small Craft Advisories may be needed early next week for breezy
winds and high waves.

Gehring

&&

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

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, X, and YouTube at:
www.facebook.com/NWSMilwaukee
www.x.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee