textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Band of moderate to heavy snow, persist across central CWA tonight into Saturday morning. Several inches of additional snow and travel impacts from gusty winds, drops in visibility, and the potential for roads to become quickly snow covered and frozen as temperatures drop. Winter Weather Advisory issued until 9 am Saturday.

- Colder and light snow linger through late Saturday morning, but chances diminish Saturday afternoon.

- A more active pattern sets up this weekend into next week, with multiple clippers bringing an inch to three inches of snow each on Sunday, Tuesday night into Wednesday, and on Friday.

- 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. Cold Weather Advisory criteria (20 degrees below zero) may be met or exceeded Sunday night into Monday morning.

UPDATE

Issued 945 PM CST Fri Jan 16 2026

A west to east band of moderate to heavy snow has set up across the central portion of the CWA tonight. Based on radar and 00z model trends this band to wobble north and south a bit, but looks to overall persist through the night as the low-level trough and forcing (TROWAL and 925mb frontogenesis band) remains anchored over the area. This paired with dropping temps, increased QPF total, and increasing SLR of 15:1 to 19:1 will all contribute increased snowfall within this band. Already have seen reports of 1-2 inches and can expect additional 2-3 inches throughout the night. Thus snow totals from this evening through Saturday morning are looking to range from 3-5 inches will localized pockets of higher amount approaching 6 inches. Given the confidence and persistence have issued a Winter weather Advisory for Sauk/Iowa counties east through Ozaukee/Milwaukee counties.

On the edges and outside of this heavy band, expect lighter snow to persist through much of the night. Models prog this moderate- heavy persisting band of snow to finally begin to shift south as the mid-level trough begins to swing east Saturday morning as surface high pressure tries to push in from the west.

Wagner

SHORT TERM

Issued 353 PM CST Fri Jan 16 2026

Tonight through Saturday night:

A broken line of snow showers has developed along a line from La Crosse to Dubuque, and will rapidly move eastward through this evening. 40 to 60 J/kg of potential instability has worked its way into southwest Wisconsin this evening within the warm sector of the low (temperatures have risen into the mid-30s this afternoon). A trigger for this instability is available upstream in the form of an arctic front currently draped corresponding to the broken line of snow showers. A northwesterly 925-850 mb jet is nosing its way through Iowa into northwestern Illinois as well, bringing potential for gusts of 35 to 45 mph along the WI/IL border as these snow showers develop. However, the main core of that wind punch is expected to remain to the south and gusts of 25 to 35 mph are expected across far southern Wisconsin.

All of these ingredients together lends credence to the potential for these snow showers to become locally intense into the evening rush hour. Visibilities as low as 1 mile have been observed in far southwestern Wisconsin, and visibilities as low as 1/2 mile are expected to develop within the most intense showers. As the showers are expected to remain scattered across southern Wisconsin, impacts will be localized, but can expect roads under these showers to quickly become snow covered as temperatures rapidly drop below freezing, with lowered visibilities from both snowfall and gusty winds creating additional hazards to travelers. The best chances for the most intensive activity are from a line from Wisconsin Dells to Madison to Janesville south and westward, although cannot rule out pulsy snow showers through the remainder of the I-94 corridor.

After the more intense snow showers end across the region this evening and the Arctic front comes through, expecting a broad area of lift to work its way into southern Wisconsin. This will bring additional light snow to the region throughout the overnight hours, with perhaps a few breaks at times. However, currently monitoring radar upstream shows light snow as far upstream as eastern North Dakota, so confidence is relatively high in continuing snowfall throughout the overnight hours. Still, with a much drier and colder airmass (lows in the teens and wind chills in the single digits below zero) in play, expecting only a half inch to an inch of accumulations.

Saturday, the final swath of wrap-around precipitation from the occluded low to the northeast pushes slowly through southern Wisconsin. A few models (namely the NAM12k and HRRR) are indicating potential for a localized, more intense band of snowfall capable of producing around 3 inches of snow, but in general expecting accumulations of 1-2 inches through the day Saturday into Saturday evening before snow tapers off completely. With highs in the upper teens to low 20s, expecting this snow to be dry, and gusty winds around 25 mph may creating blowing snow concerns as it falls as well.

Finally, Saturday night spells a end to the snow system as the low lifts northeastward into Canada and a dry Arctic high nudges into the region. Expecting low temperatures Saturday night to fall quickly into the single digits, with wind chills in the negative single digits. Winds will become lighter overnight, but will remain around 10 mph, so wind chills will certainly remain a concern.

MH

LONG TERM

Issued 353 PM CST Fri Jan 16 2026

Sunday through Friday:

Clippers, Clippers and more clippers. In one word, that is what we can expect for Wisconsin through the extended forecast. The first of these clippers looks to approach and move through Wisconsin Sunday into Monday morning. Guidance has some good consensus around 500 mb among the global models with the GFS being the one slight outlier as its slightly deeper and further south. Even with this slight discrepancy, light snow showers are expected. Snow showers are likely to start along some mid level WAA in the late morning to early afternoon then continue along a cold front into the late evening (potentially lingering into the overnight hours in the east). Snow accumulations are also expected to be light. Temperatures will drop quickly behind this cold front for Sunday night as arctic air rushes into southern Wisconsin. Overnight lows are expected to fall below zero inland with lakeshore areas at or just above 0 degrees. As temperatures fall, west to northwest winds will become breezy which will drop winds chills to around -20 to -25 (Cold Weather Advisory Criteria). With the quickly dropping temps, increasing winds and snow showers, there could be some dropping visibilites so will have to keep an eye on this system for impacts to travel. Overall a cold, windy and snowy Sunday.

As the low exits to the east Sunday night, sfc high pressure will begin to move into the Northern Plains and Great Lakes Region. This area of high pressure will be quick moving but will keep the arctic air streaming in. Day time highs will be in the single digits Monday with overnight lows falling below zero inland and at or near zero along the lakeshore. The gusty northwest winds will remain throughout the day and into Tuesday morning which will keep wind chills low around negative 20 to 25. If trends continue a Cold Weather Advisory may be needed. There will be broad cyclonic flow aloft (500mb) so can't rule out very light flurries coming out of any clouds that develop. Little to no accumulations are expected with any very light snowfall.

Heading into Tuesday, we will get our next clipper approaching. Temperatures should rebound a bit into the teens and winds turn southerly during the day. There are more uncertainties with exact timing, location and strength of the low, but guidance does suggest more snow showers. These showers should develop along a swath WAA and could swing in location from northern to southern Wisconsin based on the current guidance. Best timing looks to be Tuesday night through Wednesday. Looking further beyond this there looks to be yet another (say it with me) clipper. Guidance varies wildly for Friday on this so just know that low chance POPs around 20% will linger through the extended.

Patterson

AVIATION

Issued 945 PM CST Fri Jan 16 2026

West to east band of moderate to heavy snow will continue to impact southern WI terminals overnight into Saturday morning. MSN, UES, and MKE will see the greatest impacts with lower ceilings (1-3kft), several inches of accumulating snow, 0.5-1 in/hr snow rates, and lower visibility ranging from 1-3sm persisting through 15z Saturday. SBM as well as JVL and ENW will still see persisting snow overnight, but will be lighter with less accumulations, visibilities greater than 4sm, and high end MVFR to VFR ceilings. Otherwise, gusty westerly winds will persist tonight. Conditions are expected to gradually improve through saturday morning as the moderate to heavy snow bands shifts south and high pressure tries to work its way into southern WI Saturday afternoon.

Wagner

MARINE

Issued 353 PM CST Fri Jan 16 2026

Breezy southwest winds continue as low pressure over western Ontario swings into northern Lake Michigan this evening. The low will move into northern Lake Huron tonight and continue into eastern Ontario by Saturday. As this low moves through a cold front will move across the lake turning winds to the west. West to northwest winds will persist through Saturday night.

Another low pressure system will track from Alberta into Lake Superior Sunday afternoon and evening. Winds will turn to southwesterly and increase ahead of this system. A few gusts will approach Gales Sunday afternoon and evening. A cold front will move across the lake late Sunday evening causing winds to further increase and turn to westerly. Gales will become increasing likely Sunday night into Monday.

As the low moves east into eastern Ontario Monday, strong northwest to west winds are expected with building waves. The pressure gradient will further tighten as a high follows on the heels of the exiting low. Gales are likely during this time. Freezing Spray will also be expected as arctic air settles over the Great Lakes Region. Some heavy freezing spray is possible Sunday night into Monday.

Monday night into Tuesday winds will begin to diminish and turn to southwesterly ahead of another low pressure system tracking from Alberta towards the Great Lakes.

Patterson

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ644-LMZ645-LMZ646 until 3 AM Saturday.