textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Snow will slowly taper off from west to east through midday, with up to an inch of additional accumulation.

- Scattered snow showers (30 to 40% chance) are expected this afternoon and evening, with a front bringing a broken line of showers to the I-90/94 corridor (60 to 70% chance) and a quick drop in temperatures. Brief heavier snowfall rates are possible, along with quick reductions in visibility and snow covered roads for the evening commute.

- Light snow showers may occur later tonight (20 to 30 percent chances), with light snow showers likely Saturday (60 percent chances) and light snow likely again Sunday afternoon (60 percent chances). Accumulations should be light (under an inch each period).

- Below normal temperatures are expected this weekend through the early part of next week. The coldest temperatures and wind chills are expected Sunday through Tuesday. Wind chills may approach Cold Weather Advisory criteria (20 degrees below zero) Sunday night into Monday morning.

UPDATE

Issued 1008 AM CST Fri Jan 16 2026

Snow is slowly tapering off from west to east this morning, with visibilities down to a half mile in some places, and therefore rates around to just over 0.5"/hr across southeastern Wisconsin. Expecting up to an inch of additional snowfall this morning.

Forecast remains generally on track for the afternoon hours. Mesoscale modeling is beginning to indicate increased activity along the Arctic front this afternoon, with a broken line of snow showers possible. Have accordingly bumped up PoPs to 70% as these showers progress eastward. Best chances are along and south of the I-90/I-94 corridor as the main low level jet impulse points into northern Illinois. Quick changes in visibility are possible, and stronger showers may result in a rapidly snow-covered road.

MH

SHORT TERM

Issued 415 AM CST Fri Jan 16 2026

Today through Saturday night:

An area of light to moderate snow will continue to push east across the area this morning, bringing snow covered roads for the morning commute. This snow is being driven by a combination of upper divergence from a left exit region of a 300 mb jet streak, differential CVA in the 400 to 600 mb layer and focused warm air advection in the 925 mb to 850 mb layer. This will help bring deep upward vertical motion and saturation, which will negate any concerns for freezing drizzle. Snowfall rates of around one quarter inch per hour are expected, with one half inch per hour rates possible. An additional one half to one and one half inches of snow accumulation are possible with this round of snow.

There may be a brief lull in the snow activity after this round of snow moves out of the area by later this morning. CAMs suggest the development of scattered snow showers (30 to 40 percent chances, perhaps higher) by middle afternoon and lingering into early to middle evening. This is in response to an Arctic cold front moving east through the area in the late afternoon and evening.

There is the potential for convective snow showers to occur along and ahead of the front, with forecast soundings showing saturated and steep low level lapse rates, some weak instability and some frontogenesis response along the front. Would like to see a better wind shift and stronger winds along and behind the front for a more classic snow squall setup, though the parameter does reach 1 to 2 or a little more across the area on the NAM/GFS, with the RAP/HRRR are more aggressive with these values. Anything above a 1 is favorable for snow squalls, so they are not out of the question.

In addition, temperatures in the lower to middle 30s this afternoon should drop quickly into the 20s after the front moves through by early to middle evening, so a flash freeze is possible and may add to impacts.

At the least, some convective/intense snow showers, which is what the HRRR reflectivity forecast is showing, are possible. Will have to monitor this period for potential impacts, including quickly reduced visibility and brief heavy snowfall rates for the evening commute period.

Light snow showers may occur later tonight into Saturday morning, as the 500 mb low shifts southeast from eastern Iowa into west central Illinois. Forecast soundings keep the low levels moist with steep lapse rates in the dendrite snow growth zone. Colder temperatures will move in as well, within cold air advection.

There may be better chances (60 percent) for light snow showers Saturday afternoon, as low level frontogenesis response shifts across northern and central portions of the area and a deep moist layer within the dendrite snow growth zone develops. Any accumulations should be under one half inch.

The snow showers should wind down Saturday night, with colder temperatures moving into the area. Lows Saturday night may drop into the single digits above zero, with wind chills in the single digits below zero.

Wood

LONG TERM

Issued 415 AM CST Fri Jan 16 2026

Sunday through Thursday:

Latest models are in pretty good agreement that a shortwave will move through Sunday and bring light snow accumulations to southern Wisconsin. This system will also bring a cold front through the area by later in the day, with temps dropping to around or just below zero by daybreak Monday.

Gusty winds later Sunday into Monday will result in bitterly cold wind chills of 15 below to 25 below zero, the coldest conditions later Sunday night into early Monday morning. High temps Monday will likely struggle to get much above zero, with breezy winds persisting and keeping wind chills in the 10 below to 20 below zero range through the daytime hours. Winds should ease a bit Monday night into Tuesday, as high pressure slides by to the southwest.

Dry weather is likely Monday into Tuesday, with a shortwave possibly brining snow chances back to the area Tuesday night into Wednesday. Temperatures will be a little milder mid-week, though likely remaining below normal.

DDV

AVIATION

Issued 1008 AM CST Fri Jan 16 2026

MVFR ceilings are seen across much of southern Wisconsin, with a few pockets of IFR ceilings within heavier snowfall in southeastern Wisconsin, and within a corridor of light snow and mist in central Wisconsin. Ceilings are expected to improve to MVFR this afternoon across the entire region, falling to the 1000-1500 ft range within snow showers mid-afternoon onward. Ceilings will remain between 1000 and 2500 ft throughout the overnight hours tonight, slowly improving to VFR as low clouds exit briefly into Saturday morning. Southwesterly winds this morning will shift to become west-northwesterly this afternoon behind an Arctic front. Along and behind this front, expect scattered snow showers. A few of these showers may become locally intense, with drops in visibility to 1 SM or less and quick accumulations of up to 0.5 inch. Lighter scattered snow showers then continue through the overnight hours into Saturday.

MH

MARINE

Issued 415 AM CST Fri Jan 16 2026

Breezy southwesterly winds will continue to build over Lake Michigan today, as low pressure around 29.4 inches over western Ontario moves to the northern Lake Michigan. The low will then gradually weaken as it shifts into northern Lake Huron tonight and eastern Ontario on Saturday. The breezy southwest winds will shift westerly by early this evening, with the passage of a cold front. These winds will linger into Saturday night.

A Small Craft Advisory remains in effect for the nearshore waters of Lake Michigan into this evening, for gusty southwest to west winds. Additional Small Craft Advisories may be needed at times Saturday into early next week for gusty winds.

Winds are then expected to return to the southwest and increase for Sunday, as another low pressure system strengthens to around 29.4 inches as it tracks into the Lake Superior Sunday afternoon and evening. The associated cold front will sweep across Lake Michigan, as the low quickly pushes east into Monday.

Stronger northwesterly winds are expected to develop behind the departing low and cold front Sunday night through Monday. There will be a potential for gales during this time frame, including the nearshore waters, along with building waves.

Otherwise, low pressure around 29.5 inches shifts east later Monday, with high pressure around 30.5 inches remaining to the southwest and south of the region Monday night into Tuesday.

Given the colder Arctic airmass settling over the region and the brisk winds, expect freezing spray across Lake Michigan this weekend and continuing into next week. Some heavy freezing spray may be possible Sunday night into Monday.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 9 PM Friday.