textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Widespread rain expected tonight. Some rain-snow mix is possible across the far north, with any accumulation remaining light (half inch or less). Snow showers along the front possible and even some post frontal freezing drizzle Friday morning.

- A Wind Advisory is in effect late tonight through Friday afternoon for wind gusts of 45 to 50 mph.

- Confidence is increasing for significant accumulating snow and blowing snow Saturday night through Sunday night. Where exactly the heaviest snow will fall remains uncertain. Pay close attention to the forecast if planning to travel during this time frame.

- Accumulating sleet/freezing rain will be possible for parts of southern WI during this event as well.

UPDATE

Issued 638 AM CDT Thu Mar 12 2026

The snow showers that had developed earlier in conjunction with a shortwave trough and steep mid level lapse rates have since dissipated. Sunshine and relatively light winds are expected into the early afternoon as a sfc ridge shifts across the region. Clouds will then increase mid to late afternoon with the onset of mid level warm advection. High temps are expected to reach lower to middle 40s today. The forecast is still on track tonight for rain and snow and increasing winds.

Gehring

SHORT TERM

Issued 1159 PM CDT Wed Mar 11 2026

Today through Friday:

Conditions have quieted across the area with clear skies expected for most of tonight with high pressure largely dominating the region. A brief, transitory period of light snow/flurries cannot be ruled out late tonight given some midlevel moisture in the DGZ and some weak omega (perhaps from mild WAA). But the drier air in the low levels likely prevent much if anything from reaching the ground. Otherwise quiet weather is expected through rest of tonight.

Thursday will start fairly quiet as a upper low and corresponding surface low from the north central US will dig and strengthen into the Great Lakes region toward the late afternoon/early evening hours. Generally models have come into line on this event with models suggestive that this event will really wrap up and strengthen as it slides through northern WI. The track and strength of the system has largely led to system to trend toward a largely rain event for southern WI. Strong southerly LLJ (upwards of 80 kts) with bring strong WAA in addition to the PVA from the upper low. This should allow for some rain primarily ahead of the front during the evening and overnight hours. Earlier rain likelihood (60+%) will be largely restricted toward central WI where the better forcing near the surface low exists and where the moisture profiles near the surface are better initially. Further south, chances ahead of the front are lower (35-55%) given some drier air that may need to be overcome first.

I should begin the mention that some CAMs are suggestive of some frontal based snow showers Early Friday morning that may potentially be fairly heavy. With the strong winds expected, this situation definitely raises some concern for snow squalls. While there remains high uncertainty with this, it becomes something to watch for in models over the next 24 hrs. Then behind the front we really see CAMs dry things out in the DGZ, in fact, given cooling temperatures some freezing drizzle cannot be ruled out behind the front though snow will be possible as well, particularly further north toward the low where moisture in the DGZ may persist somewhat. Otherwise precip largely pushes out by mid morning Friday.

The primary story with this event will likely be the potential impacts from wind. The strong southerly LLJ will push in Thursday evening, which will start to increase the concern for strong winds reaching the surface given that low level sounding profiles are fairly moist to dry adiabatic. The LLJ will also get stronger toward the early overnight hours. These factors in conjunction with the increased precip likelihood has caused increased concern for Wind Advisory criteria by the mid evening hours. This particularly true if we see the best precip potential during the late evening and early overnight periods as precip loading could be a major factor in whether we end up seeing those high end winds Thursday night. However, because it is an overnight period it becomes more difficult to expect winds to naturally mix down. For now, we have started the Wind Advisory at midnight with an end time of 6PM, but the start time could be shifted earlier or later depending on the exact timing of the precip, the precip loading potential and whether we should expect much mixing overnight at all. Into the daytime hours, winds will shift westerly behind the front and with strong CAA and daytime heating we should expect to mix down winds aloft with a much higher degree of certainty. Winds will start to come back down late afternoon as the surface low begins to push out with weak high pressure moving in.

Kuroski

LONG TERM

Issued 1159 PM CDT Wed Mar 11 2026

Friday night through Wednesday:

Friday night winds will continue to decrease with a period of high pressure at the surface and zonal flow aloft. 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. Into Saturday evening and night 850mb WAA will increase significantly with LLJ factoring in as well as upper level PVA. Into Sunday additional concern will come from the impact of banding and strong Fgen that will play a significant roll in how this system plays out.

It remains difficult to gauge the level of impact this will have at this time for southern WI as there are two main uncertainties and sensitivities that will significantly affect the impact this has on any individual area. The phasing of this system suggest there are still uncertainties in track and also, although related, the location of the freezing line. These two factors will determine in large part the impact this system has. At this point we know it is going to snow a lot somewhere and there also may be significant impacts from sleet and freezing rain potential, primarily for Saturday night and Sunday. While there is no current consensus among models at this time there is the general sense the freezing line will be over southern WI somewhere with heavy snow potential directly north of that line. This has certainly increased concern for both heavy snow and icing impacts. We will continue to monitor changes over the next 48 hours as models being to focus in on the exact where and when of this event.

Otherwise Monday morning remaining snow on the back end of this system will push out through the day with weak high pressure pushing in by Monday evening. Tuesday looks largely dry at this time but into midweek there are some semblances of a few features that may bring some activity but uncertainty beyond the weekend event remains high.

Kuroski

AVIATION

Issued 638 AM CDT Thu Mar 12 2026

VFR conditions today into the evening. Very breezy south winds develop this evening shifting westerly late tnt into Fri AM. Wind gusts to 40-45 kt expected. Widespread rain mixed with snow at times, especially toward central WI, will develop this evening and continue into the overnight. MVFR Cigs and Vsbys will occur with the rain and snow toward central WI. Widespread MVFR Cigs will then overspread srn WI Fri AM.

Gehring

MARINE

Issued 638 AM CDT Wed Mar 11 2026

High pressure of 30.2 inches approaching from the west will move across Lake Michigan midday. Thus decreasing northwest winds are expected this morning then backing southerly into the afternoon as the high moves away. Strong low pressure of 29.0 inches is then expected to move through northern Wisconsin into northern Michigan tonight into Friday. Increasing southerly winds are expected late this afternoon and evening ahead of the low. Southerly gales are expected over the entire lake by late evening then becoming west northwesterly for Friday. A Gale Warning is now in effect from late this evening into Friday evening. A few storm force gusts are also possible.

Winds are expected to ease Friday night into Saturday as high pressure of 30.3 inches moves in from the northwest. Another strong low pressure system is likely to move through the region late in the weekend into early next week, with another round of gales likely. A colder air mass behind the low may lead to a round of heavy freezing spray Sunday night into Monday as the strong winds and higher waves linger.

Gehring

MKX WATCHES/WARNINGS/ADVISORIES

WI...Wind Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057- WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066- WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...midnight Friday to 6 PM Friday.

LM...Gale Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563- LMZ565-LMZ567-LMZ643-LMZ644-LMZ645-LMZ646-LMZ669-LMZ671- LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874- LMZ876-LMZ878...10 PM Thursday to 10 PM Friday.