NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 032257
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
557 PM CDT Sun May 3 2026

.KEY MESSAGES...

- Chances for showers and thunderstorms (30 to 50 percent
  chances) remain for Monday afternoon and evening, as a cold
  front moves through the area. Gusty winds could occur with
  stronger storms.

- Warmer and breezy Monday, then cooler the rest of the week.

- Frost may occur toward the middle to later portions of the
  week.

&&

.UPDATE...
Issued 557 PM CDT Sun May 3 2026

A wind shift boundary will move southeast through the area this
evening, with gusty southwest winds weakening and becoming
west. The showers and storms with the better upward vertical
motion north of the area should remain there into the evening.
Thus, kept the forecast dry. Mostly clear skies tonight are
expected, with lows in the middle 40s.

Winds will become gusty again out of the southwest Monday
morning until the cold front pushes through the area later
Monday afternoon into Monday evening. Warm temperatures in the
middle 70s are expected Monday ahead of the front, even near the
lake with the gusty southwest flow.

CAMs still show scattered showers and storms (30 to 50 percent
chances) developing along the front in the late afternoon and
pushing through into the evening hours. There is decent upward
vertical motion from frontogenesis response in the low levels.
Forecast soundings showing around 500 to 800 J/kg of skinny mean
layer CAPE in the afternoon, with deep layer bulk shear of 35
to 45 knots. There may be gusty winds that occur with any
stronger storms, with the dry air in the low levels.

Some showers may linger overnight into Tuesday in southern
portions of the area, though the cold air advection on northwest
winds may help to dry things out and keep more of this to the
south.

Wood

&&

.SHORT TERM...
Issued 121 PM CDT Sun May 3 2026

Tonight through Monday night:

Given quick clearing behind this morning's rain, high
temperatures should rise in the upper 60s to low 70s this
afternoon amid good solar insolation and warm advection on
southwesterly surface winds. A cold front is then expected to
move over the area tonight, causing breezy southwesterly winds
to ease for a bit and become westerly.

Southwesterly winds then increase again after midnight and
another shot of surface warm advection is anticipated into
tomorrow on breezy winds ahead of another cold front. Highs
will rise into the low to mid 70s. The cold front is expected to
move south into our CWA during the mid afternoon and move to
the WI/IL border into the evening. Models continue to suggest
that the environment preceding this front will be starved of
moisture, leading to skinny CAPE profiles, high based storms,
and widely scattered storm formation along the front. As such,
activity will be hit or miss during the afternoon. If a stronger
storm does manage to get going, gusty winds would be the main
threat as these storms rain into the dry near surface
environment.

Thunderstorm activity may largely wrap up by 8-9 pm but some
post frontal fgen may cause some lingering scattered rain along
the WI/IL border Monday night into Tuesday as the front slows
it's southward progression in northern Illinois.

CMiller

&&

.LONG TERM...
Issued 111 PM CDT Sun May 3 2026

Tuesday through Sunday:

Models continue to advertise much of the same from yesterday's
long term forecast for the extended period.

Following the front, a cooler patter returns Tuesday through
Thursday as a large trough dips into the Great Lakes region.
Tuesday may feature some showers along the Wisconsin/Illinois
border as the northern periphery of 700mb fgen clips the border
area. Daily highs will be in the mid to upper 50s. Wednesday
looks relatively dry as some mild surface pressure rises occur
over the upper midwest, but Thursday does look like the best
day for shower activity at this time as the base of the upper
level trough rotates through the area. Frost potential will also
return Tuesday night through Thursday night, with the most
widespread potential on Wednesday night into Thursday morning.

Temperatures then begin to warm Friday into Saturday as ridging
builds over the plains. The deterministic runs of the GFS and
ECMWF suggest a few weak WAA waves may cause nebulous shower
chances Saturday.

CMiller

&&

.AVIATION...
Issued 557 PM CDT Sun May 3 2026

A wind shift boundary will move southeast through the area this
evening, with gusty southwest winds weakening and becoming
west. The showers and storms should remain north of the area
into this evening. Thus, kept the forecast dry. Mostly clear
skies tonight are expected.

Winds will become gusty again out of the southwest Monday
morning until the cold front pushes through the area later
Monday afternoon into Monday evening.

Scattered showers and storms (30 to 50 percent chances) are
forecast along the front in the late afternoon and pushing
through into the evening hours. There may be gusty winds that
occur with any stronger storms. Ceilings should remain in the
6000 to 8000 foot AGL range during this time.

Some showers may linger overnight into Tuesday in southern
portions of the area, though northwest winds behind the front
may help to dry things out and keep more of this to the south.

Wood

&&

.MARINE...
Issued 111 PM CDT Sun May 3 2026

A weak cold front is expected to pass over the lake this
evening, easing winds for a time before winds return to a
southerly direction and become gusty again around dawn on
Monday. Winds will then increase Monday morning ahead of another
cold front in association with low pressure of 28.9 inches, and
a short 6 hour period of Gales is anticipated over the northern
third of Lake Michigan between 10am and 4pm CDT. A Gale Warning
has been issued. Winds then ease through the afternoon from
north to south over the lake as the cold front moves south.
Winds behind the front will become northwesterly.

The pressure gradient will then ease over the lake Tuesday
through Thursday, with light persistent west to northwest winds
occuring. Light and variable winds may briefly occur at times
as various weak surface ridges move west over the lake.

CMiller

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563...10 AM Monday to 4
     PM Monday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM
     Sunday.

&&

$$

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