textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Scattered flurries are expected this afternoon.

- Cold and blustery conditions with falling temperatures this afternoon. Wind chills tonight and early Thursday will fall to between -15 and -20 degrees.

- A cold and active pattern is favored next week, with additional opportunities for light snow Monday through Wednesday (30 to 60 percent chances, with the highest confidence in widespread light snow on Monday).

SHORT TERM

Issued 256 PM CST Wed Dec 3 2025

Tonight through Thursday night:

The cold front is through Milwaukee and Janesville and arctic air is spilling into southern WI. Northwest wind gusts are remaining below 20 mph. As the environment cools, the clouds will be within the snow growth zone before the dry air takes over, so expect some flurries through early evening until the clouds clear out. With the clearing skies and high pressure ridging into southern WI overnight, expect winds to decouple for all but the lakeshore.

Thus, expecting the coldest temperatures of the season so far by early Thursday morning. Models are looking a little too warm when comparing them to the 925mb temps of around -15C that are moving in, so kept the hourly and minT values from the previous forecast. Lows of -3 to -8F are expected inland, with -2 to +2 for the lakeshore counties. Wind chill values will bottom out around -17 tonight, so no Cold Weather Advisory is needed (criteria of -20). Tonight will be a case where the temp could be lower than forecast in some cold pockets, but if that happens, then there would be no wind. Similarly, temps could be slightly warmer but that would require a breeze, so wind chill values would still be in the -15 to -20 range.

Despite sunshine and light winds on Thursday, temperatures will only rebound into the 10 to 15 degree range. Wind chills will hover around 0.

Cronce

LONG TERM

Issued 256 PM CST Wed Dec 3 2025

Friday through Wednesday:

High pressure exits to the east on Friday as a clipper system propagates across southern Ontario, bringing snow showers to southern Wisconsin along its trailing cold front Friday afternoon through Friday night (20-40% chances/coverage). Meanwhile, decent agreement in modeling suggests that an atmospheric river setup will slowly sag southward into the Pacific Northwest, allowing for low pressure to develop in the vicinity of the Wyoming Rockies by Saturday. Modeling then becomes less confident on the evolution of this low as it ejects eastward. Euro and Canadian bring the low eastward, bringing a wave of snow to southern Wisconsin. Meanwhile, the GFS has a slower, weaker progression that results in weak shortwaves and very little precipitation across southern Wisconsin. Due to this uncertainty, comfortable with the NBM PoPs for Saturday night at this time (~30% chances). A cold front will work its way through the region overnight Sunday as well, bringing lows in the single digits above zero (warmer near Lake Michigan).

Arctic high pressure builds into the region Sunday regardless of the strength of the precursory system, bringing highs in the teens and lows in the single digits below zero (wind chills may dip down into the teens below zero). An atmospheric river is forecast to pivot back northward into British Columbia Sunday night into Monday, leading to primary low pressure genesis regions in Montana and Alberta and therefore a return to low pressure systems tracking primarily across southern Canada into the Great Lakes region through midweek. Multiple cold fronts and associated light snow potential will propagate through southern Wisconsin Monday through Wednesday, with the most confidence at this time in widespread light snowfall Monday into Tuesday (40-60% chances) and continual snow potential through Wednesday (30-50% chances) as additional systems propagate through.

MH

AVIATION

Issued 256 PM CST Wed Dec 3 2025

The cold front cleared Milwaukee and will arrive in Kenosha within the next hour. There are still a few flurries ahead of the front. Wind gusts behind the front are remaining less than 20 kt and there will be a downward trend the rest of the evening. Ceilings are around 1800 ft for most of southern WI, but expect them to improve to 2500 ft a little behind the cold front, and then eventually 3500 ft around the time they are clearing early this evening. Flurries are expected as the clouds rise and temperatures cool this afternoon/evening, with no accumulation or much of a visibility restriction.

Clear skies and light winds inland will allow temps to drop quickly and down below zero. Cannot rule out freezing fog in the favorable low spots. Lakeshore areas will have a little better mixing, so slightly elevated winds. Winds will become southerly on Thursday but remain light. Look for increasing higher clouds during the afternoon.

Cronce

MARINE

Issued 256 PM CST Wed Dec 3 2025

A cold front continues to progress across Lake Michigan this afternoon, currently draped across the far southern portions of the open waters. Expect gusty northwest winds behind this front, with a few gusts up to gale force possible tonight in far northern portions of the open waters. These gusts are not expected to be widespread or consistent. Very cold air combined with gusty conditions will result in periods of moderate freezing spray tonight into Thursday morning.

In nearshore regions, a Small Craft Advisory for elevated winds and waves remains in effect through tonight until 6 AM CST Thursday.

Winds shift southwesterly again Thursday as high pressure builds over the Ohio Valley. A weak low pressure system will move west to east across southern Ontario Thursday night through Friday, increasing southwesterly winds to gales across the northern third of the open waters. Elsewhere, expect gusts around 30 kt. Small Craft Advisories will again be needed during this time frame. A Gale Warning is in effect from Thursday night into Friday morning. Moderate freezing spray is expected once again Thursday night into Friday.

A cold front will drape across the open waters Friday into Friday night, bringing lighter westerly winds.

MH

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Gale Warning...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...9 PM Thursday to 9 AM Friday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 6 AM Thursday.