textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Snow showers along the cold front are possible moving through this morning, and may cause a brief drop in visibility and slick spots for the morning commute.

- A High Wind Warning is in effect until 4 PM CDT today. West to northwest winds with gusts up to 60 MPH are expected behind a cold front.

- A Storm Force Wind Warning is in effect for the southern half of Lake Michigan this evening. Gales are expected for the north half of the lake.

- Confidence is increasing for significant accumulating snow, blowing snow, and wintry mix Saturday night through Monday afternoon. A Winter Storm Watch has been issued. There does remain some uncertainty with the exact track of the low along with resultant precipitation types and totals. Pay close attention to the forecast if planning travel during this time frame.

UPDATE

Issued 655 AM CDT Fri Mar 13 2026

High Wind Warning is panning out as we continue to see gusts of 40-50 mph and occasionally up to 60 mph especially with any shower activity. Otherwise, it will be very windy through the day. Still watching the band of snow and some wintry mix across western WI to move into southern and central WI this morning. May bring drops in visibilities and slick travel for areas along and north of I-94 through the late morning.

Wagner

SHORT TERM

Issued 1145 PM CDT Thu Mar 12 2026

Early Friday Morning through Friday Night:

The approach of the precip tonight has slowed a bit but otherwise largely remains on track with rain gradually pushing in over the next few hours with some snow mixing in toward central WI. The initial period of snow has pushed through much of the area just linger toward east central WI and will exit in the next couple hours. The primary slug of precip will likely swing through the area fairly quickly, likely in and out in 3-4 hours.

Thereafter there will be increasing concerns for snow behind that precip. A few models suggest a wave of precip that may be either snow or rain right behind the primary slug of precip. If it is snow there will be some concern for a snow squall type feature but if it is largely rain, concerns would be limited. With a brief break behind that there will be a better chance for snow showers behind the front correlated with the surface low and TROWAL. Snow squall concern with that is more limited given the more broad brushed nature of it in CAMs but it could be convective which might increase concern should it become banded and more intense. These snow squall concerns are in conjunction with the strong winds where a decent snow will likely cause visibilities around a quarter mile. There is also a slight concern for some freezing drizzle behind the front as well given some loss of ice in soundings. By mid to late Friday morning the precip concerns will exit the area. Some minor snow accumulations are possible though generally expected to be an inch or less with highest amounts toward east central WI.

The other concern continues to be the wind, which on the high end will be near severe level winds, which is why the High Wind Warning is in effect. The concern had increased for precip loading with this event as winds at 900mb were 70+ knots later tonight as precip moves through so we have move the High Wind Warning earlier to account for that. Moderate rain showers to the west have already produced some 40-45 kt winds. In addition we know the 850mb jet is continuing to strengthen directly over southern WI tonight. While overnight southerly winds do not generally cause much mixing the combination of precip and how low to the surface the significant winds are caused enough concern to warrant the earlier warning time. These winds may for the most part be temporary with precip loading and southerly winds. However, later tonight into Friday morning behind the front expect winds to really pick up and become more consistent as CAA and the sun allows us to mix more significantly. Additional impacts in the morning may continue from precip loading as well. Later into the day Friday the surface low will start to push out and allow for higher pressure to nudge thus slowly lowering winds across the area through the mid to late afternoon.

Kuroski

LONG TERM

Issued 1145 PM CDT Thu Mar 12 2026

Saturday through Thursday:

Into the day Saturday, a band of midlevel moisture and WAA will slide into southwest WI and continue north through the day. Initially limited forcing and dry air may limit precip potential but gradually WAA will strengthen and begin to bring snow across southern WI by Saturday evening. This will likely occur as a result 850mb WAA will increase significantly with LLJ factoring in as well as upper level PVA.

As models have come into more focus over the last 24 hours we seem to be getting a better idea of the track with the surface low pushing through around northern IL. Still some time for this to change but this low track with a more northerly 850mb low track will drive the potential impacts of this event. There are certainly some timing deviations among the models still but later Saturday night into Sunday there is some increasing concern that we could be dry slotted for at least parts of southern WI as we lose moisture around 700mb. This may be overdone as forcing persists with moisture available for much of the rest of the profile. Toward central WI precip will likely remain through the entire period. Where precip occurs we will turn to the discussion of what type of precip. While primarily snow Saturday night there will be some potential for IP/ZR/RA/SN depending on exactly where everything sets up but snow is most likely toward Central WI. A period of ZR/IP will be possible overnight and into Sunday on the northern fringes of the dry slot. Where exactly this sets up is still uncertain at this time. Later Sunday the dry slot should push out to the east with the area of mixed precip potential swinging back to the east on the backside of the dry slot with snow pushing in right behind that. Then a prolonged period of snow would be expected in the TROWAL and in the vicinity of the upper low, in addition to the Fgen banding. Snow will linger through a good portion of the day Monday.

The exact impact of this event remains uncertain, especially now with the added concern for the dry slot undercutting some of the potential impacts. Towards central WI the chance for a significant heavy snow event remains fairly high. While some mixiness will occur at times the predominant effect will be the impact of the snow. For the rest of southern WI the impact of a potential dry slot with the SN/ZR/IP concerns will cause significant variability of impacts across the rest of southern WI. Somewhere in southern WI may significant impacts from ice. Impacts from this system may be much more limited toward the WI/IL border however with the primary impacts coming on the back end of the system with transitory Fgen.

It is worth mentioning that this will be another event with the potential for high winds given strong LLJ winds which could cause some blizzard like conditions where there is consistent heavier snow as quarter mile visibilities would be expected. Wind Advisory may be needed Sunday into Monday.

Otherwise Monday evening high pressure will push in. Tuesday looks largely dry at this time but Tuesday night and beyond may feature several weak bouts of rain/snow mixed precip events through midweek.

Kuroski

AVIATION

Issued 655 AM CDT Fri Mar 13 2026

A band of snow/wintry mix showers is moving through southern WI this morning mainly impacting MSN and SBM through the late morning. This activity may bring an hour or two of lower visibility and MVFR ceilings, but will quickly exit late morning. Otherwise expecting MVFR ceilings around 1-3kft will spread in until the early afternoon before improving. Otherwise, today main concern will the strong winds with frequent gust greater than 40kt until this afternoon. Then winds gradually ease this evening as the low pushes east and high pressure builds across the Upper Midwest.

Wagner

MARINE

Issued 1159 PM CDT Thu Mar 12 2026

A low pressure system will track from the northern plains and cross the northern half of the lake tonight into Friday morning. Winds are increasing across the lake with Gales expected across the northern half and storm force gusts across the southern half. There is a Gale Warning in effect for the north and Storm Warning for the south through 10 PM tonight. As the low pressure system tracks across the lake there will be areas of rain and snow showers. These shower will continue through Friday afternoon.

High pressure will then approach the lake Friday night causing winds to diminish. As the high crosses central Lake Michigan Saturday winds will become light and variable. This area of high pressure will quickly move east and a second low pressure system will traverse the central Plains and into the southern Great Lakes Region by Sunday. East-northeast winds will steadily increase Saturday night through Sunday as this low approaches. This low will deepen as it passes near the far southern end. Winds will then shift out of the northwest Monday as the low continues into Ontario. As this low passes there will be prolonged person of gale force winds. There is a potential that winds could become storm force as this low deepens. Additional headlines will be necessary across the Lake during this time. Mixed precipitation of snow, sleet, rain and freezing rain will be possible across Lake Michigan as this low passes.

Patterson

MKX WATCHES/WARNINGS/ADVISORIES

WI...High Wind Warning...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057- WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066- WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072 until 4 PM Friday.

Winter Storm Watch...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057- WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066- WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...7 PM Saturday to 4 PM Monday.

LM...Storm Warning...LMZ080-LMZ643-LMZ644-LMZ645-LMZ646-LMZ669- LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ870-LMZ872-LMZ874- LMZ876-LMZ878 until 10 PM Friday.

Gale Warning...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ868 until 10 PM Friday.