NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 030940
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
440 AM CDT Sun May 3 2026

.KEY MESSAGES...

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

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

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

&&

.UPDATE...
Issued 435 AM CDT Sun May 3 2026

Weak shortwave swinging through today with a fairly dry low
level but enough WAA and moisture at 700mb that we should manage
some showers reaching the surface though not everyone should
expect showers based on current CAMs. Most likely areas to see a
period of showers is across far southern WI. Things will clear
out into the afternoon becoming quiet the rest of the day.

Kuroski

&&

.SHORT TERM...
Issued 1257 AM CDT Sun May 3 2026

Overnight through Monday night:

Scattered to broken mid-level clouds should continue to move
southeast through the region overnight into Sunday. There is
some warm air advection expected overnight into Sunday, along
with a passing 500 mb vorticity maximum overnight into Sunday
morning.

These features should provide some upward vertical motion for
20 to 30 percent chances for showers. These showers will need to
overcome fairly dry air in the low levels overnight, before
trying to moisten up for a time Sunday morning. It is possible
that the showers end up gradually weakening to sprinkles or just
having virga as they shift southeast through the area overnight
into Sunday morning.

There may be a broken line of showers or perhaps a thunderstorm
later Sunday afternoon, as an initial weak wind shift boundary
pushes through the area. There is skinny mean layer CAPE a few
hundred J/kg that tries to develop along and ahead of this wind
shift boundary with some capping. Kept 20 percent chances for
showers in the northern areas this afternoon to account for this
potential.

Gusty southwest winds are expected Sunday morning into the
afternoon, shifting west. Highs should rise into the middle 60s
to around 70 degrees, including areas near Lake Michigan. The
clouds may limit highs somewhat.

Lighter winds and dry conditions tonight will give way to
another round of gusty southwest winds on Monday. There should
be highs into the lower to middle 70s with these winds and some
sunshine, including areas near the lake.

Models continue to bring a cold front southeast through the area
Monday afternoon and evening, bringing chances (30 to 50
percent) for showers and thunderstorms. Forecast soundings are
showing differing amounts of mean layer CAPE, though there
should be at least 500 J/kg with dew points in the middle to
upper 40s. Deep layer bulk shear of 35 to 40 knots with enough
mean layer CAPE may support some gusty winds with any stronger
storms, so will continue to watch this potential in coming
forecasts.

Wood

&&

.LONG TERM...
Issued 1257 AM CDT Sun May 3 2026

Tuesday through Saturday:

There should be enough of a push of cold air advection behind
the cold front later Monday night into Tuesday with northwest
winds to bring drier air into the area. The forecast still has
some 20 to 30 percent chances for showers lingering during this
time, but think these may drop lower or out of the forecast if
the drier look of the models continues.

A general elongated and broad 500 mb trough should develop over
the region by the middle portions of next week and linger into
Friday and Saturday. This pattern would generally support cool
temperatures each day, with a few showers possible at times.
Ensembles suggest the better chances for this may be Thursday,
as a 500 mb shortwave trough rotates through the area.

Lows may drop into the middle 30s away from the lake Tuesday
night, Wednesday night and Thursday night, which may allow for
frost to develop once again. Thus, frost/freeze headlines may
eventually be needed for the area each night.

Wood

&&

.AVIATION...
Issued 440 AM CDT Sun May 3 2026

Mid level CIGS expected this morning with these showers pushing
through. Light rain is not expected to bring and VSBY concerns
though periods of 5SM will be possible. Early this morning will
feature a period of LLWS but will be brief. Clouds will clear
out into the afternoon with VFR conditions expected. Quiet
tonight with the next best chance for aviation impacts Monday
afternoon and evening associated with the potential for storms.
Limited impacts expected regardless at this time.

Kuroski

&&

.MARINE...
Issued 1257 AM CDT Sun May 3 2026

South to southwest winds will increase into Sunday, as low
pressure around 29.7 inches approaches the lake. A few gusts may
approach gale force over the southern portions of the lake in
the afternoon. The low pressure system will drag a cold front
southeast over the region Sunday into Sunday evening. Winds will
become westerly for a brief period behind the front Sunday
night, before returning to southwesterly and becoming breezy
again on Monday. A few gale force gusts may occur over northern
portions of the lake on Monday.

Another stronger low around 29.2 inches and a cold front is
expected to move across the region later Monday into Monday
night. There are chances for showers and thunderstorms as the
front moves across the region. Winds will shift to the
northwest and north behind the front later Monday night into
Tuesday and weaken. High pressure around 30.1 inches building
into the northern Plains for the middle to later portions of
next week should bring lighter winds.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM
     Sunday.

&&

$$

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