textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Gusty west northwest winds behind the front will cause some blowing snow tonight.

- Scattered light snow showers are possible along the leading edge of the Arctic front Thursday afternoon. - Bitter cold temperatures and wind chills are expected Thursday night into the weekend. An Extreme Cold Warning is in effect from 12 AM CST Friday until 1 PM CST Saturday for 30 below zero and colder wind chills.

- Cold temperatures and wind chills will continue through Saturday.

UPDATE

Issued 1020 PM CST Wed Jan 21 2026

The fgen has largely pushed out of the region as the heavy banded snow and weakened/moved out of the region. However, scattered snow showers are pushing in from the west likely associated with some of the CAA aloft allowing for some convective snow shower activity this evening. While some drier air may inhibit some of this activity it is expected that this should push all the way across the CWA. We will continue to monitor conditions with these snow showers as some may be moderate to heavy at times with low visibilities but likely only last around 30 minutes of so. Onset may be sudden and may cause briefly hazardous driving conditions.

Kuroski

SHORT TERM

Issued 529 PM CST Wed Jan 21 2026

Tonight through Thursday night:

Snow is spreading into southwest WI early this evening. A band of higher snowfall rates is expected and is currently developing and beginning to pivot - it is expected to remain south of the Madison metro area, but could clip southwest Dane county. This is associated with a narrow band of low level (sfc to 850mb) frontogenesis. A Winter Weather Advisory is in effect for Iowa, Lafayette and Green Counties from 5 to 11 PM to account for the snowfall rates up to 1 inch per hour and the blowing snow that will develop behind it. Low visibility of a half mile or less is expected within this band. Total snow accumulation of up to 3 inches is expected beneath this short- lived but intense band. The advisory may need to be expanded depending on the track of this band.

Snow will exit southeast WI by midnight. Gusty west-northwest winds will develop behind the snow this evening, with gusts up to 35 mph during the overnight hours. This is behind the first push of arctic air. The main arctic cold front will arrive tomorrow afternoon. A few snow showers are possible along the leading edge of the front.

Expect rapidly falling temps down into the negative teens Thursday night, along with gusty west-northwest winds up to 35 mph (again). The combination of cold temps and gusty winds will create dangerously cold wind chill values in the -30 to -40F range Thursday night through midday Friday. The Watch was upgraded to an Extreme Cold Warning from midnight Thu nt (12 AM Fri) until 1 PM Friday. Confidence is high in reaching wind chills below -30. The lowest probability of hitting that criteria is 89 percent and that is only in far southeast Wisconsin, including Milwaukee.

The wind will be diminishing through the afternoon and evening Friday as the high pressure ridge moves into WI, so wind chill values may remain just above the warning criteria of -30. If that forecast remains on track, then the watch may roll into a Cold Weather Advisory, but if the forecast trends colder or windier, then the watch would go to a warning for the time period of Friday afternoon through mid Saturday morning.

Cronce

LONG TERM

Issued 529 PM CST Wed Jan 21 2026

Saturday night through Wednesday:

The arctic high pressure system exits our region and tracks northeastward across Montreal Saturday night, with a second (weaker) high pressure system following in the prior system's tracks, sinking southeastward from Saskatchewan into the Dakotas. The pressure gradient between these systems should be weak, leaving our region with nearly calm winds. Fortunately, jet dynamics interacting with moisture aloft are expected to produce mid to high-altitude cloud cover during this time, limiting radiational cooling and holding Saturday night's minimum temperatures to the single digits below zero (perhaps closer to zero or single digits above zero for the Lake MI shoreline). A gap in the clouds (if present) could allow temps to fall at least another 5 to 10 degrees, but again with practically calm wind.

Our forecast calls for 25-50% chances for light snow Saturday night through Sunday evening on account of the aforementioned jet dynamics and weak isentropic upglide on the northwestern fringe of the eastern CONUS winter storm. This should be a very light snowfall if applicable at all (generally 1 inch or less based on most guidance). Even the most aggressive guidance (ECMWF- ENS) for the snow has most estimates close to just 1 inch, and only a 10-20% chance of reaching or exceeding 3 inches.

Predominantly dry weather is then forecast for the remainder of the forecast period, with daytime high temperatures slowly moderating upwards into the positive teens by the middle of next week.

Sheppard

AVIATION

Issued 1030 PM CST Wed Jan 21 2026

The heavy banded snow has weakened/moved out of the region with light snow showers still in the area. However, additional scattered snow showers are pushing in now. While some drier air may inhibit some of this activity it is expected that this should push all the way across southern WI. We will continue to monitor conditions with these snow showers as some may be moderate to heavy at times with low visibilities but likely only last around 30 minutes of so. Onset may be sudden and may cause briefly hazardous conditions. Otherwise, winds will pick up across southern WI over the next few hours and likely bring some blowing snow and perhaps some temporarily reduced VSBYS. Patchy MVFR CIGS over the next few hours but VFR conditions will return early Thursday morning but may only last through the early morning. Additional snow flurries expected Thursday morning and even some snow showers and corresponding MVFR CIGS/VSBYS will be possible for the afternoon.

Kuroski

MARINE

Issued 529 PM CST Wed Jan 21 2026

Changes to the headlines: Expanded Gale Warning slightly northward and delayed the start and end times.

Low pressure of 29.6 inches will cross Lake Superior this evening. An Arctic front will surge through Wisconsin and across Lake Michigan overnight. Gale force gusts are expected over the southern two thirds of Lake Michigan, where a Gale Warning is in effect from mid evening through mid Thursday morning. Gusty westerly winds will gradually diminish Friday afternoon and night as strong high pressure around 31.0 inches over the Northern Plains expands into the Upper Midwest.

Arriving Arctic air and elevated wave heights will support periods of heavy freezing spray tonight into Friday night. A Heavy Freezing Spray Warning is in effect for this period.

The high will expand across the Great Lakes over the weekend while weakening to 30.5 inches. A weak trough around 30.2 inches will cross Lake Superior Sunday. The strong high of 30.7 inches over the Northern Plains will drop into the Central Plains at around 30.5 inches on Monday. A low pressure trough averaging 29.8 inches will sweep across the Upper Great Lakes Monday afternoon and night.

The Small Craft Advisory remains in effect for the Nearshore portions of southeast WI.

Cronce

MKX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory...WIZ062-WIZ063-WIZ067-WIZ068-WIZ069- WIZ070-WIZ071-WIZ072 until 11 PM Wednesday.

Extreme Cold Warning...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056- WIZ057-WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065- WIZ066-WIZ067-WIZ068-WIZ069-WIZ070-WIZ071- WIZ072...midnight Friday to 1 PM Friday.

Extreme Cold Watch...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057- WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066- WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...1 PM Friday to noon Saturday.

LM...Gale Warning...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 8 AM Thursday.

Heavy Freezing Spray Warning...LMZ080-LMZ261-LMZ362-LMZ364- LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 3 AM Saturday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 6 PM Friday.