West Allis, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

450
FXUS63 KMKX 041920
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
220 PM CDT Sat Jul 4 2026

.KEY MESSAGES...

- Brief funnel clouds possible in central forecast area.

- Areas of dense fog along the Lake Michigan lakeshore. Patchy
  fog possible for inland areas overnight.

- Scattered showers and thunderstorms through early evening.
  Highest coverage and the potential for strong storm or two
  will be toward the IL border this afternoon. Outside of that
  area, the risk for severe storms is low, but cloud to ground
  lightning and localized gusty winds and funnels are possible
  with any storms.

- A seasonably warm, comfortable airmass will enter the area the
  first few days of next week.

&&

.SHORT TERM...
Issued 220 PM CDT Sat Jul 4 2026

Rest of Today and Sunday:

A boundary with surface convergence developed from northwest
Iowa to south central WI. There are showers and thunderstorms
that are developing along this east-west boundary (northern Dane
County to south half of Dodge County). Before the showers
develop, funnel clouds seem to be present. We have had several
reports of funnel clouds. We have enough low level instability
(SPC mesoanalysis identifying this axis with the non-supercell
tornado parameter) to support these funnels so for now we will
handle these like landspouts with SPSs. These are brief and weak
and we cannot pick up the rotation on radar. Once the rain
develops, it wipes out the funnel. There are signs of outflow
from these storms, so that should diminish funnel chances. We
are also seeing an inland progression of the lake breeze, so
that will help cut off our chances for funnels.

Dense fog developed over the open lake and expanded to the
nearshore areas from Sheboygan to Kenosha. Models picked up on
this to some degree and most gradually shift the axis of dense
fog southward down the lake through early evening. While this is
a viable option, the forecast winds remain persistent in an
onshore/northeast direction through tonight, then increase
Sunday morning. I was not confident enough that the fog would
actually move offshore or diminish with the winds in that
direction, so I have a Marine Dense Fog Advisory for most of
Lake Michigan, including the Nearshore areas, in effect until
10AM Sunday.

An upper trough will slowly cross MN and WI tonight through
Sunday. This trough has slowed down, weakened, and trended
southward compared to previous forecasts. This trough will help
enhance northeast flow off Lake Michigan and keep southeast WI
cooler (high of mid-upper 70s, cooler along the immediate
lakeshore). Our forecast highs may be a little too warm. Expect
isolated to scattered showers to develop during the daytime
hours, with a westward progression of them as the day goes on.
Forecast soundings show very shallow moisture and instability
due to steeper low level lapse rates, so I opted to remove
thunder chances and kept pops in the 15-23 percent range.

Cronce

&&

.LONG TERM...
Issued 220 PM CDT Sat Jul 4 2026

Sunday night through Saturday:

Shortwave upper riding is expected to extend from the central Great
Plains into the Great Lakes for Mon-Tue. A sfc ridge will also
reside over the region during this time. Typical warm summer days
in the 80s is forecast.

As the shortwave upper ridge flattens, the upper level flow will
become wnwly for the remainder of the week. There will be
an organized shortwave trough and cold front in the flow either
arriving late Wed or Thu. Warm and humid conditions will be in
place ahead of this feature with potential MCS development. Rain
chances of 60-70 percent are forecast. Sfc ridging and high temps
in the lower 80s will return for Fri- Sat.


Gehring

&&

.AVIATION...
Issued 220 PM CDT Sat Jul 4 2026

Marine/Lake fog is hugging the shoreline this afternoon from
Sheboygan to Kenosha. It may affect areas up to 5 miles inland
this afternoon. The more prominent effect right now is the low
stratus that shifted inland to affect the Milwaukee area this
afternoon. Models are showing the potential for the fog/stratus
to shift southward with time through late evening, but kept it
in the forecast due to lack of confidence. If dense fog remains
in the nearshore areas through tonight, it will be possible for
the whole lakeshore counties (including MKE, RAC, ENW) after
dark since winds will be diminishing.

Also this afternoon, scattered showers and thunderstorms
developed. There were a few funnel clouds reported over northern
Dane County and southern Dodge County. The lake breeze is
progressing inland and will diminish the funnel cloud chances.

MVFR ceilings between 1500 and 3000 ft AGL are possible in east
central and toward the lakeshore all night and into Sunday
morning. Scattered-broken VFR clouds expected during daytime
heating hours on Sunday with a slight chance (15-24%) of
showers. Northeast winds will persist through the day Sunday.

Cronce

&&

.MARINE...
Issued 220 PM CDT Sat Jul 4 2026

High pressure around 30.1 inches over the Upper Great Lakes
will remain in place through Monday. Weak low pressure around
29.9 inches will slowly move east across northern Illinois into
Indiana during this time. Scattered showers and some
thunderstorms are expected over mainly the south half of Lake
Michigan through this evening. Additional showers are possible
Sunday. Areas of dense fog developed over Lake Michigan, mainly
in central portions, and is expected to expand southward
overnight. The Marine Dense Fog Advisory may need to be
expanded. There is an expectation that the fog would diminish
by mid Sunday morning with increasing northeast winds.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Dense Fog Advisory...LMZ366-LMZ565-LMZ567-LMZ643-LMZ644-LMZ645-
     LMZ646-LMZ669-LMZ671-LMZ673-LMZ675-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876 until 10 AM Sunday.

&&

$$

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