NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 041226 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
626 AM CST Wed Mar 4 2026

.KEY MESSAGES...

- Dense fog will linger at least into the middle morning hours
  for areas near the Illinois border. This may move northward
  and into southern Waukesha and Milwaukee Counties. The dense
  fog may linger into later this morning or beyond.

- Light rain or drizzle are possible (30 to 50 percent) later
  Wed night from Madison to Milwaukee and south. Light to
  moderate rain (60 to 80 percent) is expected Thursday morning
  over much of southern Wisconsin.

- Moderate to brief heavy rainfall rates are possible Friday
  into Friday night, with embedded thunderstorms expected.

- Very mild Friday and again early next week.

&&

.UPDATE...
Issued 626 AM CST Wed Mar 4 2026

The Dense Fog Advisory continues until 9 AM CST this morning for
the counties along the Illinois border, and Waukesha and
Milwaukee Counties. The area of dense fog and low stratus clouds
appears to be slowly shifting northward, and this may reach into
southern Waukesha and Milwaukee Counties. This could reach into
areas further west as well, so will continue to monitor this
trend. It is possible that the dense fog may linger into later
this morning or this afternoon, as there may not be much mixing
of the low levels despite some daytime heating. Uncertainty is
fairly high with what may transpire with the dense fog today, so
keep up with the short term forecast. The patchy freezing fog
may lead to slick spots on roads as well, until temperatures
rise above freezing.

Wood

&&

.SHORT TERM...
Issued 912 PM CST Tue Mar 3 2026

Today through Thursday:

Stratus clouds drifted back north into MKE early this evening
around high pressure over srn Lake MI. The stratus then lowered
with even dense fog over portions of se MKE County. Low stratus
and fog continue over Racine and Kenosha Counties and along the
state line toward Janesville. With stagnant conditions
expected, will maintain the low stratus and fog through the
night with patchy fog possible elsewhere. A Dense Fog Advisory
may be needed. Freezing fog and slick roads are possible over
this region.

For Wed, the stratus may continue over far se WI and near the
state line while the remainder of srn WI should see mostly sunny
skies and mild temps. Widespread low stratus, drizzle, and light
rain will then gradually develop nwd Wed nt. This is in response
to a shortwave trough approaching from the Great Plains and
reaching ern IA by 12Z Thu. Low to mid level warm, moist
advection will ensue with the aforementioned stratus and light
drizzle or rain. The shortwave trough will then pass across far
nrn IL on Thu with weak sfc low pressure late Fri nt while low pressure
tracks through wrn and nrn WI, likely reaching Ontario Sat AM.
The cold front will then pass on Sat, likely in the morning. passing
just to the south across the nrn Ohio River Valley. Thus expect
50-80 percent chances for rain on Thu with mdt rainfall rates
at times over se WI. PWATs will actually increase to 0.80-1.00
inches.

Gehring

&&

.LONG TERM...
Issued 912 PM CST Tue Mar 3 2026

Thursday night through Tuesday:

Weak shortwave ridging will briefly take hold Thu nt in the wake of
the shortwave trough. Stratus clouds will likely linger and
small rain chances will return toward daybreak over south
central WI.

An upper low over the Intermountain West Thu nt will then eject newd
as an open shortwave trough to nrn WI by 12Z Sat. A weak sfc low
or wave of low pressure will track to se MN or sw WI by Fri
evening. The GEFS does become a bit more amplified late Fri nt
as the low moves across the nrn Great Lakes. Nevertheless, a
good surge of warm, moist advection on a strong swly low level
jet is expected Fri-Fri nt. Widespread rain (80-100 percent)
with embedded thunderstorms are expected. The sfc warm front
will reach central WI by Fri evening with a cold front to
quickly follow for Sat AM. Overall the timing and evolution of
this system has been changing a bit, but a mild and wet period
is still likely. High temps in the 50s and 60s are forecast.

Afterward an active quasi-zonal polar jet stream over srn Canada
will then result in strong low pressure tracking ewd across far nrn
Ontario on Sunday and possibly again on Monday. This will
support dry swly winds and warm advection over srn WI with
continued mild temps. Rain could then return for Tue when an
upper trough digs into the Great Plains and low pressure and
cold front approach.

Gehring

&&

.AVIATION...
Issued 626 AM CST Wed Mar 4 2026

The dense fog down to one quarter mile or less and low stratus
of 200 to 300 feet AGL lingers for Janesville and Kenosha, and
other areas near the Illinois border. The area of dense fog and
low stratus clouds appears to be slowly shifting northward, and
this may reach toward Milwaukee between 13Z and 14Z. This could
reach into areas further west as well, so will continue to
monitor this trend. For now, have the dense fog and low stratus
in Janesville and Kenosha until 15Z today.

However, it is possible that the dense fog may linger into
later this morning or this afternoon in these areas, as there
may not be much mixing of the low levels despite some daytime
heating. Uncertainty is fairly high with what may transpire
with the dense fog and low stratus clouds today.

Otherwise, patchy fog should end elsewhere by middle morning,
with slick spots still possible until temperatures rise above
freezing. The low ceilings may just slowly shift northward later
today or tonight into the area, with light winds lingering.
Uncertainty here is high as well. There should be an area of
light rain or drizzle that moves northeast through the area
Thursday morning, with 1 to 3 mile visibility and low ceilings
of 300 to 800 feet AGL.

Wood

&&

.MARINE...
Issued 626 AM CST Tue Mar 3 2026

A Dense Fog Advisory remains in effect until 9 AM CST this
morning for the nearshore waters south of Port Washington and
the open waters to mid-lake from Port Washington to Wilmette
Harbor Illinois. This dense fog and low cloud deck may linger
into this afternoon and tonight, especially for the nearshore
waters, with light winds lingering. Uncertainty is high with
what may occur with the fog and low clouds during this period.

Light to modest easterly flow will then become established from
tonight into Thursday night, as weak low pressure passes across
the northern Ohio River Valley.

Low pressure around 29.5 inches will develop in the central
Plains Thursday night, and track toward the Upper Mississippi
River Valley by Friday evening. This low will move near or just
north of Lake Michigan later Friday night into Saturday morning,
quickly moving into Quebec by Saturday evening.

As the low passes to the north, breezy southerly winds will
develop for Friday afternoon and night, then shifting northwest
on Saturday with the passage of the cold front. Widespread rain
and embedded thunderstorms will accompany the approaching and
passing low Friday into Friday night.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Dense Fog Advisory...WIZ065-WIZ066-WIZ067-WIZ068-WIZ069-WIZ070-
     WIZ071-WIZ072 until 9 AM Wednesday.

LM...Dense Fog Advisory...LMZ644-LMZ645-LMZ646-LMZ671-LMZ673-LMZ675-
     LMZ777 until 9 AM Wednesday.

&&

$$

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