NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 121050
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
450 AM CST Fri Dec 12 2025

.KEY MESSAGES...

- Areas of very light snow or flurries this afternoon and
  evening with the passage of an arctic front.

- An Arctic airmass settles in this weekend with wind chills
  ranging from -10F to -30F late Friday night through Sunday
  night. A Cold Weather Advisory is in effect from Madison to
  Milwaukee and north toward central WI from late tonight
  through Saturday morning. Another advisory will likely be
  needed Sat nt-Sun AM for all of Srn WI.

- Next week temps return to near normal with daytime temps
  around or above freezing by midweek.

&&

.SHORT TERM...
Issued 450 AM CST Fri Dec 12 2025

Today through Saturday:

The upper trough over Manitoba will amplify as it moves sewd
into Ontario today and tonight. Cyclogenesis will ensue north of
Lake Superior this afternoon and continue ewd as well. This will
drive the arctic front, currently over wrn MN, through srn WI
this evening. Areas of very light snow or flurries can be
expected with the frontal passage. Brisk nwly winds and very
cold temps will drop the wind chill temps to -20 to -25F for Sat
AM from Madison to Milwaukee and northward. Thus a Cold Wx
Advisory is now in effect.

During the day on Sat, a frontogenetic band of light snow will
move across IA and IL, but it could clip far srn WI. 20-40%
chances of light snow are forecast near the IL border. High
temps only in the single digits above zero are forecast. An
upper trough axis will then swing sewd from Canada Sat nt,
thereby reinforcing the arctic air. Low temps well below zero
for well inland locations are forecast along with wind chill
temps of -20 to -29F over all of srn WI. The arctic high around
1045 mb will reach IA by 12Z Sun then move ewd into the Ohio
Valley by Sun nt. Swly winds and warm advection will then begin
Sun nt but still with cold temps and wind chills hanging on.


Gehring

&&

.LONG TERM...
Issued 450 AM CST Fri Dec 12 2025

Saturday night through Thursday:

The arctic high pressure weakens and pushes southeast of the
region Monday, continuing into the Atlantic Ocean through mid
week. Breezy southwest winds (strong WAA) are expected through
the first half of next week, likely boosting daytime highs around
or slightly above the freezing mark Tuesday, then towards 40
degrees for Wednesday. Strong low pressure tracking eastward
across Canada will allow the WAA to continue the pace even as the
arctic high dissipates and merges into the Atlantic mid week. Dry
weather is looking likely through the first half of the week.

Predictability drops from mid next week onwards, but models do
hint at a passing low pressure system, which could be anything
from a small clipper system (00z-GFS) to a more dominant synoptic
low pressure system (00z-ECMWF). We've left precip chances
(30-40%) in the forecast from Wednesday evening onwards to
compensate.

Sheppard

&&

.AVIATION...
Issued 450 AM CST Fri Dec 12 2025

Patchy light freezing fog through 14Z. Otherwise VFR conditions
until MVFR Cigs develop ahead of the arctic front this afternoon
with MVFR Cigs continuing in the evening with flurries. The
stratus clouds will then dissipate by late tnt.


Gehring

&&

.MARINE...
Issued 450 AM CST Fri Dec 12 2025

Light and variable winds this morning will give way to breezy
southwest winds this afternoon as low pressure around 29.7 inches
develops north of Lake Superior and moves east through the
weekend. The low will sweep an arctic front across Lake Michigan
tonight, with a prolonged period of brisk northwest winds and
heavy freezing spray for much of the weekend.

High pressure around 30.8 inches will move southeast from the
northern Plains and through the western Great Lakes late Sunday.
Winds ease later Sunday as the high approaches, but gusty winds
may return early next week as the high exits into the Ohio River
valley.

Brisk nwly winds has resulted in a Small Craft Advisory from
Sheboygan to Winthrop Harbor for this evening through Sun A>

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Cold Weather Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-
     WIZ057-WIZ058-WIZ059-WIZ060-WIZ063-WIZ064-WIZ065-
     WIZ066...midnight Saturday to noon Saturday.

LM...Heavy Freezing Spray Warning...LMZ080-LMZ261-LMZ362-LMZ364-
     LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
     LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
     LMZ878...midnight Saturday to 9 AM Sunday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...9 PM
     Friday to noon Sunday.

&&

$$

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