textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Bitter cold temperatures and wind chills are expected tonight into the weekend. An Extreme Cold Warning is in effect from 12 AM CST Friday until 1 PM CST Saturday for wind chills 37 to 42 below zero. An Extreme Cold Watch is in effect from 1 PM CST Friday until 12 PM CST Saturday for wind chills of 20 below to 30 below zero.

- Cold temperatures and wind chills will continue later this weekend into next week.

SHORT TERM

Issued 445 AM CST Thu Jan 22 2026

Today through Saturday:

Some low clouds will move southeast through the area at times this morning, before more low clouds develop this afternoon. West winds this morning will become gusty this afternoon, with highs in the teens expected.

There should be yet another Arctic cold front that shifts southeast through the area this afternoon, exiting to the south this evening. Forecast soundings do show saturated low levels with steep lapse rates in the dendrite snow growth zone developing this afternoon. There is some low level frontogenesis response with the front, though it does not look like there is low level instability and a strong enough wind shift for robust convective snow showers/squalls. However, may still see at least a few snow showers and some flurries develop this afternoon, and kept 20 percent chances going in the forecast.

Strong cold air advection tonight into Friday on gusty northwest winds will bring the Arctic airmass into the region. Lows look to be well into the teens below zero, with wind chills bottoming out in the 37 to 42 below zero range early Friday morning. Fairly confident in these values occurring, given the brute force cold air advection.

Thus, the Extreme Cold Warning continues later tonight into early Friday afternoon, as the wind chills remain below 30 below zero during this period. Frostbite can occur in as little as 10 minutes when wind chills get to 40 below zero.

The Extreme Cold Watch remains in effect for Friday afternoon into Saturday morning. There is still some question as to how cold temperatures and wind chills will get during this period.

Highs Friday are currently forecast in the 3 below to 8 below zero range, but may vary as the cold air advection ends and even a little modification of the airmass occurs in the afternoon. The forecast highs are just below the 50th percentile of model guidance, and the spread is relatively small. So, small variations in the highs may result, with wind chills in the 20 to 30 below zero range Friday afternoon still expected.

Lows and wind chills into Friday night and Saturday morning are also somewhat in question, as the Arctic high moving into the area weakens winds and sets up a low level inversion versus some clouds moving into the region. This will affect how cold it gets and subsequent wind chills. For now, have lows of 10 below to 18 below zero Friday night, with wind chills generally 20 below to 30 below zero.

The forecast highs are again just below the 50th percentile of model guidance, and adjustments lower may be needed if the clouds do not materialize as predicted. Thus, kept the Extreme Cold Watch in place for now until more confidence is gained with the lows and wind chills Friday night into Saturday morning. Either way, bitter cold conditions are expected.

There is some potential for a lake effect snow band to push westward toward the lakeshore Saturday, mainly in the afternoon, as a convergent band sets up over the lake and possibly pushes westward. Kept some 20 to 30 percent chances for snow showers in the forecast for this possibility. Will wait and see how later model runs handle this feature.

Wood

LONG TERM

Issued 445 AM CST Thu Jan 22 2026

Saturday night through Wednesday:

Southern Wisconsin could get clipped by light snow Saturday night into Sunday, as low pressure passes by well to the south. Kept precip chances generally under 50 percent during this time frame though, as there remains a fair amount of uncertainty with how far north the snow will be as the surface low lifts into the Ohio River Valley.

The better chance for snow during this time period might come from a lake effect potential, due to the cold airmass in place along with a period of winds backing from east to the north. Models have started to show some run to run consistency with this possibility, so may have to bump precip chance up in future forecasts.

Otherwise, the story will be continued cold weather through the weekend, with lows 5 below to 10 below zero Sat night and Sun night, and highs only 10 to 15 on Sunday. Winds will be light Sat night, but will be higher Sunday night, resulting in wind chills possibly in the -15 to -25 range.

Dry weather is expected Monday under high pressure, with a light snow potential Monday night as a shortwave moves through. Tuesday and Wednesday then look dry under high pressure. Temperatures are expected to be a few degrees milder for the first half of the week, though likely remaining below normal.

DDV

AVIATION

Issued 445 AM CST Thu Jan 22 2026

Some low ceilings around 3000 to 4000 feet AGL will move southeast through the area at times this morning, possibly lowering to 2000 to 2500 feet AGL at times. More low ceilings around 2500 to 3500 feet AGL should develop this afternoon. West winds this morning will become gusty this afternoon.

There should be yet another Arctic cold front that shifts southeast through the area this afternoon, exiting to the south this evening. At this time, at least a few snow showers and some flurries may develop with the frontal passage this afternoon. Brief visibility drops may occur with the snow showers.

Ceilings should gradually scatter out and dissipate tonight into Friday, with gusty northwest winds bringing bitter cold air into the area. The gusty northwest winds will weaken Friday afternoon, as Arctic high pressure approaches from the northwest.

Wood

MARINE

Issued 445 AM CST Thu Jan 22 2026

Low pressure around 29.6 inches will move into Quebec today, with gusty west winds lingering over Lake Michigan. Gale force gusts are expected over the southern two thirds of Lake Michigan into the middle morning hours, where a Gale Warning is in effect. A period of west to northwest gales are expected tonight into middle morning on Friday over the southern two thirds of the lake, and a Gale Warning is in effect for this period as well.

A Small Craft Advisory is in effect for the nearshore waters of Lake Michigan through Friday, for gusty west to northwest winds. Freezing spray is possible, mainly toward the open waters.

Gusty northwest 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.

The gusty winds, Arctic air and elevated wave heights will support periods of heavy freezing spray into Friday night. A Heavy Freezing Spray Warning is in effect for this period across all of Lake Michigan.

The high will expand across the Great Lakes over the weekend, while weakening to around 30.5 inches. This should help winds gradually weaken over Lake Michigan.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...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.

Gale Warning...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876- LMZ878...6 PM Thursday to 9 AM Friday.

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.