textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Freezing drizzle to cause slick roads across south central Wisconsin until later this evening. A Winter Weather Advisory is in effect for this area.

- Widespread light snow will linger until later this evening for mainly southeast and east central Wisconsin.

- Another round of light snow is expected later Wednesday morning and afternoon, with amounts ranging from a dusting to under 1 inch. The best chances for snow amounts around an inch will be south of Madison.

- Single digit temps and wind chills of 5 below to 15 below zero are expected overnight New Years Eve into New Years Day.

UPDATE

Issued 816 PM CST Tue Dec 30 2025

A Winter Weather Advisory has been issued until 10 PM CST this evening for south central Wisconsin, as freezing drizzle has resulted in slick roads and travel impacts. This freezing drizzle was being driven by 925 mb warm air advection with no ice crystals available from western to south central Wisconsin.

This upward vertical motion should shift southeast of the area by later this evening, with drier air in the low levels moving southeast toward the area. So, the freezing drizzle should end by later this evening. Will watch radar and observation trends and see if the advisory needs to be extended beyond 10 PM CST this evening.

There may be some light freezing drizzle that occurs overnight toward the Dells and Montello, if there is enough lingering moisture and upward motion. Will continue to look at this potential with the 00Z suite of models.

The light to moderate snow continues across east central and southeast Wisconsin, as the main 500 mb vorticity maximum shifts through the region with some 850 mb to 700 mb warm air advection. This upward vertical motion will continue to slide southeast of the area by later this evening, so the snow should come to an end as well.

Wood

SHORT TERM

Issued 248 PM CST Tue Dec 30 2025

Tonight through Thursday:

An initial round of light snow has mostly fizzled out but new development, from a stronger shortwave trough currently over ne MN, is occurring across nrn and central WI. The upper wave will quickly track to east central WI by early this evening then to the border of lower MI with Ohio and nw IN by 06Z Wed. A wnwly LLJ of 40 kt will nose sewd from se MN into sw WI ahead of the upper wave; thereby enhancing warm advection over all of srn WI, and generating 850 mb frontogenesis over ern WI. Thus the better lift and snowfall rates will be late this afternoon and early evening. Overall expect QPF (0.1 or less) and snowfall to still be light and will range from 1/2 inch or less of snow accum over sw WI to 1.5 inches toward east central WI. Will continue to message the snowfall and potential travel hazards for the late afternoon and evening commute. The snow will then end from west to east around 01-05Z Wed.

Yet another stronger shortwave trough will then track sewd over Ontario and the nrn Great Lakes on Wed in response to an incredibly deep cyclone of 953 MB, which will occlude and retrograde across nrn Quebec and Hudson Bay through Thu. A polar cold front will accompany the aforementioned upper wave and will shift swd across the region from late Wed AM into the afternoon. Low to mid level frontogenesis along a strong tropospheric temperatures gradient will likely generate more light snow during this time. The Fgen values are fairly low and believe snow accums will remain light. Cold advection to then prevail Wed nt then slow down on Thu as high pressure tracks from srn MN to the Ohio River Valley. Lows New Year's morning will range from 1 below to 6 above zero with high temps climbing into the teens. Wind chills will bottom out at 5 below to 15 below zero around sunrise New Year's Day.

Gehring

LONG TERM

Issued 248 PM CST Tue Dec 30 2025

Thursday night through Tuesday:

Troughing over the northeastern United States and eastern Canada and northwest flow will keep us cold and dry to start the extended period. Overnight lows Thursday night through Saturday night will range from the single digits to low 10s with daytime temps Friday and Saturday in the upper teens to low 20s. This will be accompanied by high pressure arching from North Dakota into the eastern Corn Belt.

Temperatures moderate toward normal in the mid to upper 20s on Sunday as the center of the high pressure passes over the state and moves southeast into Indiana, allowing for south winds to return. Sunday evening, the NBM feathers slight chance PoPs (10 to 20%) into the area as global models vary widely on the placement of a passing, WAA-driven wave. The current spread for the expected snow band is as far south as the WI/IL border to as far north as Lake Superior, so nothing is set in stone for this wave at this time.

Otherwise the start of next week looks quiet with temperatures remaining around normal.

CMiller

AVIATION

Issued 816 PM CST Tue Dec 30 2025

Freezing drizzle should linger at Madison and Janesville until later this evening, before dissipating. Low ceilings below 1000 feet AGL may occur at times, though should mostly be 1000 to 1500 feet AGL into the overnight hours. There may be some light freezing drizzle that occurs overnight north of Madison. Light northwest winds are anticipated overnight into early Wednesday morning.

The light to moderate snow continues across east central and southeast Wisconsin including Sheboygan, Waukesha, Milwaukee and Kenosha. The snow should come to an end as well across these areas by later this evening. Light northwest winds are anticipated overnight into early Wednesday morning, with ceilings in the 1000 to 1500 foot AGL range.

Ceilings should generally stay in the 1000 to 2000 foot AGL range Wednesday into Wednesday evening, with northwest winds gradually increasing. An area of light snow will develop by midday across most of the area, except Sheboygan where some drier air may limit the snow.

The snow should linger through the afternoon and end by early Wednesday evening. Visibility should be in the 1 to 2 mile range with the snow, with snowfall rates of up to one quarter inch per hour. The snow character will be fluffy and powdery.

Wood

MARINE

Issued 248 PM CST Tue Dec 30 2025

Modest west to northwest winds will prevail this afternoon and tonight as strong low pressure remains over Quebec and a weak cold front moves across Lake Michigan. The strong low over Quebec will then move over eastern Hudson Bay for Wednesday into Thursday which will aid in moving a stronger cold front across Lake Michigan. Thus brisk northwest winds and moderate freezing spray is expected for Wednesday through Thursday morning. A few gale force wind gusts will be possible over far northern Lake Michigan Wednesday into Wednesday evening. Modest to brisk west to northwest winds will then continue the remainder of the week. A Small Craft Advisory may be needed Wednesday afternoon and night from Sheboygan to Winthrop Harbor, but confidence is low at this time.

Gehring

MKX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory...WIZ046-WIZ047-WIZ056-WIZ057-WIZ062- WIZ063-WIZ067-WIZ068-WIZ069 until 10 PM Tuesday.

LM...None.