textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Winter Storm Warning for Saturday and Saturday night. A significant winter storm will impact southern Wisconsin Saturday into early Sunday. Widespread snowfall totals of 8 to 12 inches, with locally higher amounts possible. Travel will be difficult, especially Saturday afternoon and evening when snowfall rates will be highest.

- Below normal temperatures will likely persist through next week.

UPDATE

Issued 935 PM CST Fri Nov 28 2025

Snow is now moving into ern IA but do expect it to slow down and/or evaporate as the 700 mb baroclinic zone weakens as it approaches srn WI. Thus have delayed the onset a snow by a couple hours or so across srn WI for Sat AM. The snow will overspread ern WI by 14-16Z with the heaviest snowfall rates for srn WI as a whole from late morning into the early evening. This corresponds to the nose of a sly 40-50 kt LLJ that will shift ewd across nrn IL and far srn WI during the afternoon. 850-700 mb warm, moist advection and frontogenesis supported aloft by increasing PVA will be the main mechanisms for deep lift. The initial shortwave bringing the PVA will lift newd from IL through ern WI during the evening and will be followed by a larger shortwave trough across nrn IL during the late evening and overnight. The sfc low is still expected to track from nrn MO Sat afternoon to near Chicago by 06Z Sun with a few millibars of deepening expected. These features will support a 2nd round of 850-700 mb frontogenesis that will shift from nern IL nwd to east central WI during the evening then quickly back swd as the low moves away across lower MI. In addition, the sely fetch will support at least 12 hours of lake enhanced snow for Sheboygan, ern Fond du Lac, Washington, and Ozaukee Counties with less effects from LES to the south. Thus expect heavier QPF and snow totals over ern WI vs. south central WI. 8-12 inches of snow accum is forecasted for south central WI with the lowest totals nw of Madison, while 10-15 inches is forecast for ern WI but locally more where the lake enhanced snow is the heaviest. Winter Storm Warning continues for Sat-Sat nt.

Gehring

SHORT TERM

Issued 400 PM CST Fri Nov 28 2025

Tonight through Sunday:

Stubborn clouds this afternoon should decrease in coverage late afternoon into the evening. This will likely allow temperatures to tank for a few hours as winds will be light, before clouds begin to increase by late evening ahead of an approaching winter storm. Will probably see a few spots drop into at least the upper teens.

A significant winter storm is then expected to impact all of southern Wisconsin Saturday into early Sunday. There are a couple changes to note from the previous forecast. The first is that overall forecast snow totals have come up a bit. ECMWF deterministic and ensemble mean liquid equivalent precip totals have held pretty steady over the last several runs, while the GFS and associated ensemble mean have gradually increased over the last 24 hours. The short term meso models are not surprisingly on the high end with totals along with the NAM. The lowest totals are still with the Canadian solutions. Knowing that models can get a little excited with QPF 1 to 3 days out, kept totals on the moderate side, at or below many model solutions. Still ended up with pretty healthy totals though. Feel these totals are reasonable given good support for lift with the low track, low level and upper level jet placement, decent frontogenesis and warm air advection, and no issues with dry air entrainment during the bulk of the system. Also kept snow to liquid ratios on the conservative side, averaging around 15 to 1 for the bulk of the event. A few models have as high as 20 to 1 during portions of the storm. Bumped the SLRs down a bit in the east due to some milder temps along the lakeshore, but that milder air will be very shallow.

Another change from the previous forecast is increased confidence for higher lake enhanced totals along and east of the Kettle Moraine. Between the moisture increase from the lake, increased lift due to solid sfc to 850 mb temp diffs, and some low level convergence, looks like there could be a notable swath of higher amounts in the east. There is a pretty consistent signal for this among the latest meso models. In the end, the snow totals were bumped up to 8 to 12 inches across the forecast area per the above mentioned reasons, with totals of 10 to 14 inches possible in eastern areas. These higher totals will likely be localized, due to the nature of frontogenetic banding and lake enhancement.

The highest snowfall rates will be during the afternoon and evening hours tomorrow, and could be as high as 1 to 2 inches an hours at times, especially in the east. Average short term model visibilites are between 1/4 and 1 mile during this time frame, with travel likely difficult due to the reduced visibilities and snow covered roads.

Snow will wind down by daybreak Sunday. Though the snow will have ended, winds will pick up by early Sunday, with some blowing and drifting of the freshly fallen snow possible. Northwest winds are expected to gust 25 to 35 mph through the morning, with winds gradually easing during the afternoon.

DDV

LONG TERM

Issued 400 PM CST Fri Nov 28 2025

Sunday night through Friday:

Following the active weekend and snow, expect Arctic air to settle across the area overnight Sunday through Monday. High pressure and light winds paired with the anticipated fresh snow will contribute to an early season cold snap. Nightly low temps for Sunday night and Monday nights are looking to dip into the single digits and potential even dip below zero for inland locations of southern WI with single digit below zero wind chills. Meanwhile high temps on Monday will only top off in the teens to lower 20s, which is around 15-20F below normal for this time of year. Additionally with a shortwave trough and associated surface progged to trek from the Plains and along/just south of the Ohio River Valley, cannot rule out a glancing chance of snow Monday night into Tuesday morning. Overall any snow accumulations looking minimal as southern WI sits on the northern fringes of the QPF and best forcing lingering to our south.

Tuesday through midweek begin to see temps rebound briefly back toward, but still below normal. Long range models are hinting at a bit more of an active cold pattern with a few rounds of additional snow. Next chance will be Wednesday with a passing cold front passage. High pressure and Arctic air will filter in behind the front towards the end of the week with single digit temps overnight and sub-zero wind chills. Another bout of snow will be possible with a few passing systems across the Upper Midwest later Friday through the weekend. Could see an addition few inches with each system given the cold pattern. So will need to keep an eye on the later week impacts.

Wagner

AVIATION

Issued 935 PM CST Fri Nov 28 2025

VFR conditions for much of tnt over srn WI but with MVFR Cigs and Vsbys developing over south central WI from 9-13Z as light snow develops. This area of light snow and Cig and Vsbys restrictions will overspread all of srn WI by 15-16Z. Cigs will then fall well below 1 kft for the remainder of the day and night with vsbys ranging from 1/2-1 mile as the snow becomes heavier. Periods of 1/4SM +SN will be possible over ern WI.

Gehring

MARINE

Issued 400 PM CST Fri Nov 28 2025

High pressure working across the region will bring the lighter, west- northwesterly winds this evening, but will begin to see winds back to the south and easterly overnight into Saturday as low pressure tracks across KS Saturday morning to the south tip of Lake Michigan Saturday night. Will be a brief six hour window of stronger south-southeasterly winds and expecting to reach gale force gusts as the low pressure approaches later Saturday into Saturday evening and a gale warning is issued for the southern third of the lake, while small craft conditions for southern WI near shores. Winds will weaken below gale as the low pressure passes the southern tip of Lake Michigan overnight Saturday, but small craft conditions for the nearshores continue as we see this low deepen as it lifts into Lake Huron by mid- Sunday. Stronger northwesterly winds will develop and expect to reach gale force once again across the open waters with the colder air mass moving into the region. Thus a Gale Watch is in effect for Sunday. High pressure will then build in later Sunday into the start of next week with light winds.

Wagner

MKX WATCHES/WARNINGS/ADVISORIES

WI...Winter Storm Warning...WIZ046-WIZ047-WIZ056-WIZ057-WIZ062- WIZ063-WIZ064-WIZ067-WIZ068-WIZ069-WIZ070-WIZ071- WIZ072...3 AM Saturday to 6 AM Sunday.

Winter Storm Warning...WIZ051-WIZ052-WIZ058-WIZ059-WIZ060- WIZ065-WIZ066...6 AM Saturday to 6 AM Sunday.

LM...Gale Warning...LMZ080-LMZ675-LMZ777-LMZ779-LMZ876-LMZ878...3 PM Saturday to 9 PM Saturday.

Gale Watch...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM Sunday to 7 PM Sunday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...9 AM Saturday to 11 PM Sunday.