NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 120427
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1027 PM CST Sun Jan 11 2026

.KEY MESSAGES...

- Mild to start the workweek, with the warmth peaking on Tuesday
  (highs in the mid 40s).

- The next low pressure system brings 20-45% light rain chances
  on Tuesday, followed by 35-75% light snow chances Wednesday.

- Turning colder for the second half of the week into next
  weekend.

&&

.UPDATE...
Issued 1025 PM CST Sun Jan 11 2026

The weak upper level lift and shallow layer of mid level
moisture have worked together just enough to allow for some
very light precipitation to develop across east central
Wisconsin. These isolated showers will quickly move east over
the next hour and will be very light. The narrow areas of 30
dBZ on radar are likely the only spots where these flurries will
be capable of making it to the ground as dry air in the low
levels will prevent anything else from reaching. For areas that
do see these flurries a trace of snow is possible, but it will
be near impossible to measure with the breezy winds. Otherwise
no major changes to the forecast.

Patterson

&&

.SHORT TERM...
Issued 310 PM CST Sun Jan 11 2026

Tonight through Monday night:

There remains some slight potential (~30% chance) that some snow
flurries could develop over portions of southern WI this
evening (especially east-central WI) between 8 PM and 11 PM CST
this evening, driven by some weak 500mb PVA and 800-700mb WAA
interacting with the shallow moist layer (containing the
currently observed stratocumulus clouds across the region). That
being said, with the cloud bases generally 2,000 ft above ground
or higher, and plenty of dry air both above and beneath this
layer, the odds of this happening have decreased since the prior
forecast iteration. Either way, no measurable accumulation will
come of it.

A southwest breeze develops tonight, working with the lingering
cloud cover to hold overnight low temperatures to the mid 20s
tonight (despite our thin snow pack). Continued dry and quiet
weather on tap for Monday and Monday night, with highs around 40
degrees and lows around freezing.

Sheppard

&&

.LONG TERM...
Issued 310 PM CST Sun Jan 11 2026

Tuesday through Sunday:

The unseasonably warm temperatures peak on Tuesday, with highs
in the mid 40s expected. A low pressure system tracks east
across Lake Superior Tuesday afternoon, with 20-45% rain chances
across the region Tuesday morning and afternoon (highest in
east-central WI), with a lull in the rain chances possible
Tuesday evening (due to a dry slot resolved on most model
guidance). Late Tuesday night, precipitation chances begin to
increase again as a potent cold front and the 500mb trough swing
through, with a rain/snow transition expected to complete at
some point Wednesday morning. The daytime hours of Wednesday
feature a 35-75% chance for light snowfall (highest further
east in Wisconsin). ECMWF-ENS and GEFS total snow plumes
describe the synoptic snowfall with this system as relatively
light (with the plumes centered around a half inch to 1 inch
snowfall, and some of the members making up the higher
percentiles leaning towards 2-3 inches). Precip chances taper
Wednesday night, but with 1 caveat, the due north winds on the
back side of the low coupled with lake surface to 850mb delta T
would suggest the formation of a lake effect snow band (oriented
North-South somewhere towards the southern end of the lake).
Exactly where this band sets up is uncertain, but we will have
to monitor the exact wind directions to ensure that it doesn't
meander west and clip far southeastern Wisconsin. Most ensembles
take the lake effect band and it's heavier accumulations well
clear of our CWA.

Cooler temperatures are expected for the late half of the work
week, with daytime highs in the 20s to around 30. Another low
pressure system with additional snow chances (possibly a clipper
system) is possible later this week, followed by colder
temperatures into the upcoming weekend.

Sheppard

&&

.AVIATION...
Issued 1025 PM CST Sun Jan 11 2026

Intermittent MVFR ceilings around 1.5 to 3 kft will be moving
out with the upper level ceilings over the next couple of hours.
This cloud deck has already cleared western Wisconsin and
remains across eastern. As these clouds clear so to does the
very small chance for flurries across east central Wisconsin.
VFR conditions are expected through the rest of the period.
There will be a period of clear skies lasting a couple hours
before more high level clouds move in from the west. These high
level clouds will be BKN to SCT which will leave breaks in the
deck through Monday morning before clearing by the afternoon
hours.

The LLWS of 40 to 45 kt southwest winds at 2 kft will linger
into the overnight time period. As winds come up at the sfc and
become breezy the speed wind shear potential will decrease and
end. Breezy southwest winds with gusts of 20 to 30 kts are
expected into early Monday morning once they develop. Light
westerly winds will take over Monday late morning becoming light
southwesterly by Monday night.

Patterson

&&

.MARINE...
Issued 310 PM CST Sun Jan 11 2026

Broad high pressure around 30.5 inches over the lower Mississippi
River Valley will work with low pressure around 29.5 inches over
Hudson Bay to drive southwest to west winds over Lake Michigan
tonight. From late this evening through late tonight, a surface
pressure trough extending south of the low will accelerate these
winds (to around 30 kt at times). Winds gradually decelerate
through the daytime hours of Monday.

Breezy south to southwest winds are expected Tuesday ahead of
another low pressure system around 29.3 inches. This low pressure
system will track east across Lake Superior Tuesday afternoon,
shifting winds to northwesterly Tuesday night. There is potential
for north to northwesterly gales behind the associated cold front
Wednesday through Wednesday night. Moderate freezing spray may
occur with these gales.

Sheppard

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 6 AM
     Monday.

&&

$$

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