West Allis, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

507
FXUS63 KMKX 060525
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1225 AM CDT Mon Apr 6 2026

.KEY MESSAGES...

- Increasing potential for pop-up/convective snow showers this
  afternoon and evening, especially over east central Wisconsin.
  Some late afternoon/evening commute impacts may occur, caused
  by sharp visibility drops and light slushy accumulations on
  roadways. Some freezing of wet surfaces may occur tonight as
  temperatures drop.

- A mix of light rain and light snow may occur Tuesday night
  (40 to 60 percent chances), with a little light freezing rain
  mixed in as well. Best chances for this would be toward
  Wisconsin Dells and Montello.

- Active pattern continues Wednesday into next weekend, with
  multiple additional periods of rain and a few thunderstorms.

&&

.SHORT TERM...
Issued 1225 AM CDT Mon Apr 6 2026

Today through Thursday:

Any rain showers should exit the area to the southeast over the
next hour or so. There may be some partial clearing that occurs
overnight, before the next area of clouds moves into the area
from the north. Northwest winds should develop overnight and
gradually pick up by dawn. They will become gusty during the
morning hours and linger through the afternoon.

There continues to be increasing potential for pop-
up/convective snow showers this afternoon and evening, mainly
toward east central Wisconsin and possibly affecting areas east
of Interstate 41 and south toward Milwaukee. There is decent
upward vertical motion from more differential CVA aloft, with
low level frontogenesis response with the cold front passing
southward through Lake Michigan and eastern parts of the area.

Forecast soundings are showing steep low level lapse rates with
perhaps up to around 100 J/kg of mean layer CAPE toward the
Sheboygan area, with lower instability values to the southwest.
HREF continues to show potential for at least scattered
convective snow showers with snowfall rates of one half inch
per hour (perhaps up to one inch per hour with the
instability), which seems reasonable given the setup. There
should also be mild ground temperatures that drop quickly Monday
evening, so there may be some refreezing of wet roads.

This does not seem to be a classic snow squall setup at this
time, but certainly a good setup for these convective snow
showers. They may reduce visibility to 1 to 2 miles or less in
a short amount of time, with the snow rates and gusty winds.
Any accumulations may be tough to come by on the warmer roads,
but may see wet, slushy accumulations under an inch on grassy
surfaces.

Thus, some impacts to the late afternoon/early evening commute
are possible, especially toward east central Wisconsin. Will
continue to monitor this potential and message accordingly.

High pressure should bring quiet weather Tuesday, with continued
cool temperatures in the lower 40s. Onshore winds near the
lake will keep highs in the 30s there.

There remains a 40 to 60 percent chance for light rain and light
snow mix Tuesday night, with some light freezing rain possibly
mixing in. Forecast soundings continue to show this potential,
as warm air advection on gusty south winds helps bring a
gradually warmer layer of air in the low levels but above the
surface. It may be more of a transition from light snow to a
wintry mix to light rain Tuesday night, with mainly light rain
Wednesday morning. The best chances for this will be toward
Wisconsin Dells and Montello. Will continue to monitor this
potential.

The gusty south winds should bring warmer highs into the 60s
inland, with perhaps 50s closer to the lake with south southeast
winds developing. A cold frontal boundary sagging into the area
from the northwest Wednesday night into Thursday should bring
continued rounds of showers with a few storms possible at
times. Better chances look to be Wednesday night (60 to 80
percent chances), with 30 to 40 percent chances lingering
Thursday.

Another mild day Thursday with highs into the 60s are
anticipated with gusty southwest winds. Temperature confidence
is relatively high, as ensembles are showing small spreads in
the forecast ranges of temperatures Wednesday into Thursday.

Wood

&&

.LONG TERM...
Issued 1225 AM CDT Mon Apr 6 2026

Thursday night through Sunday:

Ensembles remain in some disagreement with the progression of
the frontal boundary across and south of the area Thursday night
into Saturday. Some take the front to the south of the area
later Friday into Saturday, keeping the area generally dry.
Others stall it out across southeast and far southern parts of
the area, with continued chances for showers and a few
thunderstorms at times. For now, will maintain at least 20 to 30
percent chance for showers and a few thunderstorms at times
Thursday night into Saturday, until more clarity on the frontal
boundary location can be seen.

Temperature spreads in the ensembles are relatively small
during this period, considering the uncertainty with the frontal
boundary. They generally point to mild temperatures, with highs
well into the 50s and lows in the middle to upper 30s. Cooler
values near the lake may occur if winds become onshore.

Ensemble means are generally showing south to southwest flow
and warm air advection at the surface later in the weekend, with
possible warming temperatures into the 70s by Sunday. Spreads
in the temperatures are still fairly low, with most ensemble
members showing the warmer trend. Chances (generally 40 to 50
percent or more) for showers and a few storms may linger at
times into Sunday, with the warmer and more moist airmass moving
into the region.

Wood

&&

.AVIATION...
Issued 1225 AM CDT Mon Apr 6 2026

Any rain showers should exit the area to the southeast over the
next hour or so. There may be some partial clearing that occurs
overnight, before the next area of ceilings around 3500 feet
AGL moves into the area from the north. They should remain
around 3500 feet AGL through the day and evening. Northwest
winds should develop overnight and gradually pick up by dawn.
They will become gusty during the morning hours and linger
through the afternoon.

There continues to be potential for pop-up snow showers this
afternoon and evening, mainly toward the Sheboygan terminal and
possibly affecting Waukesha and Milwaukee terminals by late
afternoon/early evening. Snow showers with snowfall rates up to
one half to one inch inch per hour are possible with the gusty
northwest winds.

May see visibility drop quickly to 1 to 2 miles or less at
times, with ceilings varying between 2500 and 3500 feet AGL.
There should also be mild ground temperatures that drop quickly
Monday evening, with some quick refreezing potential. May see
wet, slushy accumulations under an inch mainly on grassy areas
toward the Sheboygan terminal if these persist.

Winds will become north tonight and weaken, with ceilings
gradually shifting out of the area.

Wood

&&

.MARINE...
Issued 1225 AM CDT Mon Apr 6 2026

Northwest winds will linger overnight, as high pressure around
30.7 inches builds into the northern Plains. These winds will
increase once more during the day Monday, as a small area of low
pressure around 30.0 inches develops east of Lake Huron. A few
gale force gusts are possible over the northern half of the open
waters during the afternoon hours.

Winds will decrease Monday night into Tuesday, as high pressure
around 30.5 inches moves over and east of the area. Some moderate
freezing spray is possible over the northern half of the lake
Monday evening.

A Small Craft Advisory is in effect for later this afternoon
and tonight for the nearshore waters, for increasing northwest
winds and building waves.

Low pressure around 29.6 inches will form over the northern Great
Plains and approach Lake Michigan Tuesday night into Wednesday,
resulting in increasing southerly winds across the waters. Winds
will remain gusty into Wednesday night, as the low passes north
of Lake Superior. Gale force gusts will be possible with this
system.

A Small Craft Advisory will likely be needed for the Wednesday
into Wednesday night period for the nearshore waters, with a few
gale force gusts possible.

Winds will taper during the day Thursday, with high pressure
around 30.4 inches moving from the northern Plains toward Lake
Superior. Showers and a few thunderstorms are forecast Wednesday
into Thursday.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...4 PM
     Monday to 7 AM Tuesday.

&&

$$

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