NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 171147
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
647 AM CDT Tue Mar 17 2026

.KEY MESSAGES...

- Light accumulating snowfall will occur tonight into Wednesday
  morning. 1 to 2 inches of snow are expected across the area,
  with 2 inches most likely southwest of Madison. Patchy
  freezing drizzle is possible as snow exits.

- Temps gradually warm up through the end of the week.

&&

.UPDATE...
Issued 650 AM CDT Tue Mar 17 2026

Current forecast remains on track. No major updates other than
letting the Gale Warnings expire this morning.

Wagner

&&

.SHORT TERM...
Issued 1218 AM CDT Tue Mar 17 2026

Today through Wednesday:

Low pressure exiting into Ontario as Arctic high pressure presses
into Wisconsin will lead to lowering northwesterly winds and low
temperatures in the single digits along the lakeshore and near
zero inland this morning. A few areas in central Wisconsin may
see lows in the single digits below zero. Morning wind chills in
the negative teens are expected.

Winds will shift to southerly this afternoon, bringing in warming
temperatures and highs in the low 20s. Temperatures will hover in
the upper teens overnight tonight as a warm frontal feature
brings in light snow from west to east. As this warm front lifts
into Lake Michigan late tonight into Wednesday morning, surface
temperatures will rise into the 20s and an 850 mb warm nose may
develop at the same time as the dendritic growth zone desaturates.
Pockets of freezing rain and freezing drizzle become possible for
a brief period as snow exits. Expecting 1-2 inches of snow for
much of southern Wisconsin, with a light glaze of ice possible
into Wednesday morning. The best chances for up to 2 inches of
snow are expected from Madison westward.

Precipitation ends from west to east Wednesday morning, with
southwesterly winds continuing to bring in warmer air. Highs near
40 degrees are expected.

MH

&&

.LONG TERM...
Issued 1218 AM CDT Tue Mar 17 2026

Wednesday night through Tuesday:

A quick-moving shortwave will progress through southern Wisconsin
Wednesday night, bringing a mix of rain and snow showers through
the late overnight hours. Temperatures are expected to remain at
or just above freezing, leading to no freezing rain expected. A
trace of snow is possible. Precipitation tapers off into Thursday
morning, and ridging returns for highs in the 40s.

Ridging looks to remain dominant through the weekend, with high
temperatures in the 50s and potentially creeping into the 60s in
southwestern Wisconsin by Saturday as a low pressure system
propagates through southern Ontario and brings strong southerly
winds to the area. A few showers are possible (~15% chance)
Saturday night into Sunday as a cold front slowly progresses
through southern Wisconsin. Highs in the upper 40s to low 50s are
expected Sunday, with northerly winds continuing through the
overnight hours and lows in the 20s. A more active pattern returns
early next week as multiple shortwaves bring chances for on and
off showers and cooler temperatures in the 40s.

MH

&&

.AVIATION...
Issued 650 AM CDT Tue Mar 17 2026

High pressure will be working its way across southern WI today
bringing lighter and variable winds through the afternoon along
with prevailing VFR conditions. Will see clouds and MVFR
ceilings build in from west to east later this evening and
overnight as snow moves into the area. Expecting snow to bring
lower visibilities and some accumulation through Wednesday
morning. The higher snowfall ranging from 1-3 inches is
expected mainly for MSN and southwest, while the rest of
southern WI terminals are likely to see anywhere from a dusting
to generally less than an inch through Wednesday morning. Will
see the snow activity move out through the morning and cannot
rule out some light freezing drizzle to mix in on the backside
of the snow, but overall potential remains low. Otherwise expect
winds to increase from the south-southwest while lower ceilings
linger behind the departing snow through Wednesday morning.

Wagner

&&

.MARINE...
Issued 1218 AM CDT Tue Mar 17 2026

Low pressure of 28.6 inches continues to exit into Quebec this
morning while Arctic high pressure of 30.3 inches presses into
the northern Plains. This will lead to continued gales across the
open waters, and a Gale Warning is in effect through 7 AM CDT.
Gales may end earlier than forecast, and a early cancellation
may be sent. Even after gales end, heavy freezing spray is
expected to continue. A Heavy Freezing Spray Warning is in
effect through 11 AM CDT. Winds will diminish and become light
and variable midday today, before shifting to become
southwesterly and increasing tonight as low pressure of 29.7
inches progresses through the southern Canadian Prairies tonight
through Wednesday. A weak cold front from this low will shift
winds to westerly overnight Wednesday before an additional weak
low tracking through Illinois shifts winds back to southerly,
then northerly Thursday. Winds will remain variable through the
weekend as multiple weak systems move through the Great Lakes
region.

MH

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
     LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
     LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 7 AM
     Tuesday.

     Heavy Freezing Spray Warning...LMZ080-LMZ261-LMZ362-LMZ364-
     LMZ366-LMZ563-LMZ565-LMZ567-LMZ643-LMZ644-LMZ645-LMZ646-
     LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-
     LMZ872-LMZ874-LMZ876-LMZ878 until 11 AM Tuesday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 11 AM
     Tuesday.

&&

$$

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