textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Widespread accumulating snowfall this evening into early Sunday. Snow totals generally of 1"-4" north of I-94 and 3" to 6" south. A Winter Weather Advisory is in effect for portions of southern Wisconsin.

- Below normal temperatures will persist much of next week. Additional rounds of light snow at times next week, possibly mixed with rain later Tue into early Wed.

SHORT TERM

Issued 324 AM CST Sat Dec 6 2025

Today through Sunday:

Clouds will likely decrease in coverage this morning as high pressure briefly moves through the area. Colder temps are expected today behind the shortwave that moved through last evening, with well below normal highs in the low to mid 20s.

Clouds will then quickly return to the area later today into this evening as a shortwave approaches from the west. This system will bring widespread accumulating snowfall to southern Wisconsin during the evening and overnight hours, winding down west to east early Sun morning. While there remains some differences among model solutions as to the amplitude of the shortwave and strength/placement of the surface low, the overall trend has been towards a farther north and snowier solution for southern Wisconsin.

The bulk of large scale models and mesoscale models show ample forcing via warm air advection and frontogenesis, especially across the southern forecast area. The deterministic GFS continues to remain on the lower end with precip amounts but is notably lower than the GEFS ensemble mean. While the dendrite growth zone isn't very deep per latest model soundings, the DGZ is expected to be in the heart of the better forcing. Between this and the colder nature of the system, expecting snow to liquid ratios of 14-17 to 1. With the precip totals trending upward, these ratios give forecast snow totals of generally of 1"-4" north of I-94 and 3" to 6" south.

Not out of the question to see some lake enhancement come onshore later tonight into early Sunday, particularly from Milwaukee southward. Still some uncertainty with the mean flow from the surface to 850 mb though, so confidence isn't high in lake enhancement. Still opted to put a slight bump up in totals in the far southeast to reflect this potential.

Given the higher expected snowfall totals and increased overall confidence in this snow event, a Winter Weather Advisory has been issued for roughly the southern half of the forecast area. Could see the need for the advisory to be expanded northward a bit if this northward model trend continues.

Clouds will decrease Sunday morning into early afternoon behind the departing low pressure system. Despite the sunshine, highs will be chilly, only topping out in the upper teens to low 20s most places. Breezy northerly winds will keep wind chills in the single digits above zero through the day. Could see little lake effect snow in the far southeast forecast area Sunday night as winds veer from northerly to easterly. Not expecting much more than a dusting given that the wind direction will be changing through this period, limiting a prolonged fetch from any particular direction.

DDV

LONG TERM

Issued 324 AM CST Sat Dec 6 2025

Monday through Friday:

High pressure will bring dry and continued well below normal temps to the area Monday. A quick moving shortwave may bring a dusting of snow to southern Wisconsin Monday night as the high pushes eastward. Another low pressure system is expected to move through the area later Tuesday into early Wednesday. Models continue to suggest a more northern track with this system, which could lead to a little rain/snow mix, particularly in the southern forecast area. A colder airmass is then expected to quickly return to the area behind the low Wednesday night into Thursday, with more snow chances returning on Thursday, possibly lingering into Friday.

DDV

AVIATION

Issued 324 AM CST Sat Dec 6 2025

A mix of MVFR ceilings early this morning will likely give way to mainly VFR conditions during the day today. Upstream clouds have been decreasing in coverage and daytime mixing will help to raise the bases of any remaining clouds. Light west to northwest winds today will become light and variable this evening ahead of an approaching trough. This trough will then bring widespread accumulating snowfall to southern Wisconsin this evening into early Sunday.

Snow is expected to move in west of Madison between 01Z and 03Z this evening, spreading eastward and reaching lakeshore areas between 04Z and 06Z. Snowfall rates of generally 0.25" to 0.5" an hour are likely during the main accumulating period, though there could be some banding that pushes rates briefly towards 1" an hour. The best chance for these higher rates is currently expected to be along and south of I-94. Latest forecast snow totals range from roughly 1-4" north of I-94 and 3-6" south, the highest totals southwest and lowest northeast. The snow is expected to wind down west to east from 10Z to 14Z early tomorrow morning.

The snow will lean towards the drier variety, with snow to liquid ratios of 14-17 to 1. Ceilings will drop to 1 kft or lower during the main period of accumulating snowfall, with visibilites largely in the 1 to 3 mile range, occasionally down to 1/4-1/2 mile in any heavier snow bands.

DDV

MARINE

Issued 324 AM CST Sat Dec 6 2025

Breezy westerly winds this morning will gradually ease while veering to the northwest today, as high pressure of 30.0 inches builds in from the west. Breezy northerly winds are then expected later tonight into Sunday as low pressure passes by to the south and strong high pressure of 30.5 inches begins to build in from the west. More rounds of gusty winds are expected at times through at least the first half of next week, as multiple low pressure systems move through the region.

DDV

MKX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory...WIZ056-WIZ062-WIZ063-WIZ067-WIZ068- WIZ069...8 PM Saturday to 6 AM Sunday.

Winter Weather Advisory...WIZ064-WIZ065-WIZ066-WIZ070-WIZ071- WIZ072...10 PM Saturday to 8 AM Sunday.

LM...None.