textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Temperatures will rapidly fall well below freezing this evening, with any untreated surfaces becoming slick.

- After a lull in the precipitation, snow will gradually spread east across all of southern Wisconsin this evening and become heavier overnight.

- A Winter Storm Warning is in effect toward central and east central Wisconsin. A Winter Weather Advisory is in effect over most of the rest of southern Wisconsin. Accumulating snow of 2 to 6 inches, strong winds and reduced visibilities are expected, highest toward central and east central Wisconsin.

- Northwest wind gusts to 50 MPH are expected by later tonight, with a few gusts up to 55 MPH possible later tonight into early Monday morning near the lake. A Wind Advisory is in effect into Monday evening.

- A Storm Warning is in effect through early Tuesday morning over the open waters of Lake Michigan. Moderate freezing spray is also expected. The highest gusts are expected later tonight into Monday afternoon.

- Polar air returns later tonight and continues through the end of the week, with temperatures remaining near or below normal.

UPDATE

Issued 801 PM CST Sun Dec 28 2025

No changes are expected to the current winter weather headlines at this time.

The strong cold front has made its way through the area, for northwest winds behind it starting to ramp up and become gusty. This will continue to bring a rapid fall of temperatures well below freezing this evening, which may lead to untreated surfaces becoming slick.

The rain is exiting to the northeast of the area, with a brief lull in precipitation from a dry slot. Snow has already made its way east into parts of south central Wisconsin, and will continue to spread eastward through the evening. The snow is expected to become heavier overnight, especially toward central and east central Wisconsin, as the main area of low level frontogenesis response and the TROWAL axis shifts through the area.

Snowfall rates of one half inch or more per hour should occur overnight into early Monday morning in this area, with lower rates to the south. The snow character should gradually become more fluffy and powdery overnight into Monday morning, as the colder air moves in with the strong northwest winds that are expected within a tight pressure gradient and good low level mixing.

Northwest gusts up to 50 MPH are expected overnight into Monday morning, possibly to 55 MPH near the lake. This will bring blowing and drifting snow, which will help reduce visibility. The lowest may be toward central Wisconsin, where one half mile or less visibility values are possible with the heavier snow rates and amounts.

Will need to monitor these areas overnight into early Monday morning for these potential conditions. For now, the Winter Storm Warning continues into Monday morning for Marquette and Green Lake Counties, and into Monday afternoon for Fond du Lac and Sheboygan Counties.

The Winter Weather Advisory continues for most of the rest of the area into Monday, mainly for the combination of snow and blowing snow reducing visibility. The Wind Advisory also continues into Monday for the strong northwest winds. Most of the snow will end by midday Monday, but there may be lingering blowing and drifting snow impacts in eastern parts of the area, so the winter weather headlines linger into the afternoon there.

Wood

SHORT TERM

Issued 245 PM CST Sun Dec 28 2025

Tonight through Monday night:

Dense fog has lingered a bit longer than expected but has finally started to clear a bit this afternoon leaving lighter fog for much of the area in addition to widespread showers. This system carries significant lift with the upper low, strong WAA and strong Fgen with the early parts of this system as it bombs out across the Great Lakes. This is expected to bring rain across southern WI through the afternoon. Toward the late afternoon early evening ahead of the front we expect a dry slot to lower chances across the southern parts of the CWA but possibly across most of the CWA for a period. However, as the front slides in and the strong TROWAL swings in behind it temperatures will rapidly decrease with rain changing over to snow from west to east from late this afternoon through the evening. In addition that is when we expect winds to really start to ramp up as the LLJ pushes overhead over the course of the evening.

The increasing winds this evening and snow have lead us to issue a Wind Advisory across all of southern WI, as well as a Winter Weather Advisory and Winter Storm Warning for parts of southern WI through part or most of Monday. QPF for this event post changeover to snow is fairly light around 0.25 to 0.5 inches with somewhere around a 10-13:1 snow ratio event average. Many models suggest higher snow ratios but those do not really account for the wind that will most certainly break down flakes. So the focus with this event becomes the QPF and so snow totals are looking likely to be in the 3-6 inch range toward central WI and decreasing to around an inch toward the WI/IL border. The reason for the Advisory/Warning has a large degree to do with the impact of winds and blowing snow that will impact visibilities and conditions overall. This will lead to near blizzard conditions and perhaps even a few periods of blizzard- like conditions. Expect decreasing temperatures tonight to cause some concerns for flash freezing.

It is worth noting a few things; there are a few models that suggest some higher end QPF and snow with this event particularly toward central WI and that ignores the snow ratio concerns of being too high. So there are still some lingering scenarios that bring some higher snow than currently expected. In addition, late tonight into Monday morning there is a significant uptick in the higher end wind potential as we become unstable and we start to tap into increasingly strong LLJ winds aloft. Models suggest in the neighborhood of 60 mph winds possible. If this is realized then snow, especially if higher than expected and these higher end winds would likely lead to blizzard conditions as quarter mile visibilities would be expected. Thus we cannot rule out the need to upgrade to a Blizzard Warning for northern parts of the CWA.

Through Monday morning snow will end across southern WI. However, winds will remain gusty and thus blowing snow concerns will remain. The Wind/Winter Headlines are then expected to end by noon to the west and at 6pm to the east as gusty winds will linger to the east a bit longer.

Winds will linger Monday night as temperatures fall to the single digits bringing apparent temps in the negative single digits overnight.

Kuroski

LONG TERM

Issued 245 PM CST Sun Dec 28 2025

Tuesday through Sunday:

Northwest flow and colder temperatures will persist through the extended period with a few shortwaves moving through mid week. The better of the two shortwaves looks to move through on Tuesday afternoon into Tuesday evening, bringing some potential for light snow to the northeast half of the CWA. NBM PoPs are currently around 30 to 45%, but may increase heading into Tuesday as model agreement increases.

Another weaker shortwave is this expected Wednesday afternoon along with a reinforcing shot of cold air as an arctic cold front sinks south. QPF is very hit or miss, so blanket chance PoPs have been introduced along the front.

Beyond, the extended looks to remain quiet as high pressure moves in, with temperatures remaining at or below freezing.

CMiller

AVIATION

Issued 801 PM CST Sun Dec 28 2025

The rain has moved mainly northeast of Sheboygan terminal, with a brief lull in the precipitation. The snow has already moved east into parts of south central Wisconsin, and should reach Madison and Janesville around 9 PM and the eastern terminals between 10 PM and 11 PM this evening.

The snow will become heavier overnight into early Monday morning, especially toward Sheboygan. Lower rates and amounts are expected further south toward Janesville and Kenosha. Rates up to one half inch per hour or more may occur toward Sheboygan, with up to one quarter inch per hour rates for most of the rest of the area. Snow character will gradually become more fluffy and powdery overnight into Monday morning, as colder temperatures move in with the strong winds.

The gusty northwest winds are already ramping up and will continue to strengthen overnight into Monday morning. They will remain gusty Monday afternoon and evening, before weakening later Monday night. Gusts to 40 to 45 knots are anticipated overnight into Monday, highest for terminals near Lake Michigan.

These winds will also bring blowing and drifting snow, especially on north to south runways. This should bring reduced visibility to 1 to 3 miles with the snow, perhaps lower toward Sheboygan and toward central Wisconsin. The reduced visibility may linger into Monday afternoon and evening.

Ceilings should remain below 1000 feet AGL overnight, before rising up to 2000 feet AGL Monday morning and possibly scattering out from west to east in the afternoon. Visibility during the snow should be 1 to 3 miles, with lower values at times toward central Wisconsin and Sheboygan. Blowing snow may limit visibility to 1 to 3 miles into the afternoon.

Wood

MARINE

Issued 801 PM CST Sun Dec 28 2025

Low pressure around 29.5 inches will quickly strengthen to around 28.8 inches as it moves from southern Lake Michigan to Lake Huron tonight into Monday morning. As this strengthening occurs, a very strong pressure gradient is expected to move over Lake Michigan, causing widespread northwesterly storm force winds.

Gales should begin over the southern end of Lake Michigan early this evening and quickly spread northward over the lake. Storm force winds are then anticipated later tonight into Monday afternoon for the open waters. A Storm Warning is in effect for all of Lake Michigan into early Tuesday. Winds will back off slightly from storm force to gales late Monday afternoon and then continue into early Tuesday. High waves are also expected during this period.

A Gale Warning is in effect for the nearshore waters of Lake Michigan into Monday evening, for west northwest gales.

After the period of storm force winds and gales, breezy northwest flow below gale force will last late into the week.

CMiller/Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...Wind Advisory...WIZ046-WIZ047-WIZ056-WIZ057-WIZ062-WIZ063- WIZ067-WIZ068-WIZ069 until noon Monday.

Winter Storm Warning...WIZ046-WIZ047 until noon Monday.

Wind Advisory...WIZ051-WIZ052-WIZ058-WIZ059-WIZ060-WIZ064- WIZ065-WIZ066-WIZ070-WIZ071-WIZ072 until 6 PM Monday.

Winter Storm Warning...WIZ051-WIZ052 until 6 PM Monday.

Winter Weather Advisory...WIZ056-WIZ057-WIZ062-WIZ063-WIZ067- WIZ068 until noon Monday.

Winter Weather Advisory...WIZ058-WIZ059-WIZ060-WIZ064-WIZ065 until 6 PM Monday.

LM...Storm Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563- LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 6 AM Tuesday.

Gale Warning...LMZ643-LMZ644 until midnight Tuesday.

Gale Warning...LMZ645-LMZ646 until midnight Tuesday.