textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Light snow accumulations are likely Sunday late morning into Sunday night. Accumulations will generally range from 0.5 to 1 inch across the area. - Milder this upcoming week with highs in the low to mid 20s, and potential for temperatures near freezing Thursday and Friday.

- More light snow looks possible later in the work week.

UPDATE

Issued 931 PM CST Sat Jan 31 2026

The temperatures are falling quickly with high pressure and calm winds over southern WI this evening. I nudged the forecast lows down a couple of degrees closer to zero inland from Lake Michigan for tonight. High clouds will start to move in toward daybreak and winds will begin increasing out of the south, so temps will start to rebound.

The light snow on the leading edge of a surface trough approaching from the Northern Plains is currently over MN and IA. The initial area of clouds and light snow will be battling low level dry air as it gets into south central WI just after sunrise, so it will probably take until the afternoon for that deeper moisture and more widespread snow to get into the area. Steadier but light snow is still looking likely for the late afternoon and evening hours.

Cronce

SHORT TERM

Issued 247 PM CST Sat Jan 31 2026

Tonight through Sunday night:

Any remaining cloud cover is expected to clear this evening and skies should remain mostly clear tonight as a high pressure ridge moves southeast across the state. Amid the subsidence and light winds, temperatures are expected to tank with lows in the low single digits.

Southerly winds will increase around daybreak as the high pressure moves east out of the area. 850mb WAA and weak 850mb fgen will then drive light snow as a shortwave moves east southeast into the state from Minnesota. The initial wave of WAA is expected to move in during the mid morning and track toward the lakeshore into the early afternoon. Following this initial wave, there may be a bit of a lull in snow for a few hours during the mid afternoon, before the main surface trough swings through during the late afternoon into the evening, bringing another round of snow. Overall snowfall rates are expected be very light throughout the day, around 0.1 in/hr up to 0.25 in/hr at times. Accumulations will also be fairly light as well given the rather weak forcing. A half inch is expected over southern Wisconsin from Sunday morning into Sunday night, although an inch of accumulation looks possible where the snow from the WAA wave and sfc trough overlap. Right now this looks best for areas from Madison, westward.

CMiller

LONG TERM

Issued 227 PM CST Sat Jan 31 2026

Monday through Saturday:

Northwest flow over the Upper Midwest and troughing over the Eastern US will continue to promote relatively dry and at to below average temperatures through Wednesday. Monday should be mostly cloudy, but high pressure sinking southeast into the state will promote clearer skies for Tuesday and Wednesday.

Thursday, a stronger low pressure is expected to form over the MN/Canada border region and track east over Lake Superior. Its positioning will promote southerlies and some modest WAA over the area. Temperatures will rise to near freezing and the WAA will drive light snow Thursday into Friday. Another push of arctic air then looks possible behind a cold front in association with this low, and temperatures may dip back into the teens next weekend.

CMiller

AVIATION

Issued 931 PM CST Sat Jan 31 2026

We can see light snow over MN and IA that is associated with a surface trough of low pressure. That trough will slowly move across WI Sunday and Sunday night. Snow on the leading edge will arrive in south central WI Sunday morning but will encounter dry air in the low levels. It may take until early afternoon for any snow to start reaching the ground as that trough makes its way across srn WI. Madison could see a few tenths of an inch of dry snow during the afternoon, and Milwaukee has a lower chance of seeing any measurable snow in the afternoon due to that dry air.

The trough will continue over srn WI during the evening and slightly more moisture will be available for light snow to reach the ground. Up to a half inch is possible for all of srn WI during the evening. Snow will end from west to east, clearing eastern WI around 3AM.

Cronce

MARINE

Issued 256 PM CST Sat Jan 31 2026

Breezy north winds over the southern half of the lake are expected to ease this evening as high pressure sinks southward across the lake. Winds are then expected to come around to southwesterly by daybreak on Sunday as low pressure moves east over Lake Superior. Southwest breezes to 20 knots are then expected Sunday into Sunday night until a cold front passes over the lake Monday morning. Light to moderate northwest winds are then expected to continue until late in the work week when a low approaches the lake.

CMiller

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None.