textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Patchy freezing drizzle may linger this morning.

- A Winter Weather Advisory is in effect for portions of southern Wisconsin for snow accumulations as well as the potential for some freezing rain. This will bring impacts to travel Tuesday evening into early Wednesday morning.

- Additional rounds of light snowfall are then possible at times later Thursday through the weekend.

- Below normal temperatures continue through next weekend, with wind chills as cold as -15 to -25 degrees Friday and Saturday night.

SHORT TERM

Issued 432 AM CST Tue Dec 9 2025

Today through Wednesday:

Left a mention of freezing drizzle in the forecast this morning based on weak reflectivities on radar and some lower visibilities to the west. Confidence is low though, given very few upstream observations with precipitation.

Attention then turns to a more potent low pressure system that is expected to zip through the region later today into Wednesday, with the low expected to move through the far northern forecast area. Ample warm advection and frontogenesis aloft will lead to a round of precip ahead of the low, with a showery setup under the low as it moves through, then some additional precip on the back sided of the low. The leading round of precip as well as the precip north of the low and behind the low will be primarily snow. Will likely see a mix of rain/snow or even all rain for a time under and to the south of the low. Additionally there is a chance that freezing rain could mix in with the snow initially across west and southwest portions of the forecast area. Several models show surface temps warming up at the same rate as temps in the lowest couple thousand feet though, which would suggest mainly a snow to rain transition. So, confidence isn't particularly high in the freezing rain potential at this time.

Given the current expected low track, kept the northern forecast area in a Winter Weather Advisory for the snow total potential of 2 to 5 inches. Though rain could briefly mix in even in northern areas, the warmer period would be short lived, with some snow moving back in behind the low. A few counties farther southwest were added to the advisory due to the initial burst of snow (though totals will be lower) as well as the above mentioned potential for a little freezing rain. Though winds will be gusty during this system, the snow will be wetter, limiting any blowing or drifting.

A lingering concern with this system is that fact that models still vary with the track of the low, with a couple short term models taking the low quite a bit farther north. These models are north of pretty much all of the ECMWF, GFS, and Canadian ensemble member low tracks, so not putting much weight in them at this moment. The large scale models initialized the low position north of Montana pretty well this morning. These low track differences are worth watching though, as there is a fairly tight gradient with expected precip types and totals. A wiggle north would push the higher now totals out of the forecast area, but a wiggle south would bring them farther into the forecast area.

Any lingering snow Wednesday should wind down by early afternoon, with decreasing clouds expected overnight.

DDV

LONG TERM

Issued 432 AM CST Tue Dec 9 2025

Wednesday through Monday:

Colder temperatures will push into the region Wednesday night through the end of the week, as multiple shortwaves move through, possibly also bringing a little light snow at times. By this weekend, high temperatures may not get out of the single digits most places. Overnight wind chills this weekend may dip as low as -25. Temps will then slowly recover early next week, but will remain well below normal.

DDV

AVIATION

Issued 432 AM CST Tue Dec 9 2025

Left a mention of freezing drizzle in the forecast this morning based on weak reflectivities on radar and some lower visibilities to the west. Confidence is low though, given very few upstream observations with precipitation.

Widespread precip is then expected to move in by early this evening, with mainly snow for the first round. Could see some freezing rain mix in from the Madison area westward and to the south, though confidence is not high in the freezing rain potential. Snow will likely transition to rain from north to south from mid-evening into early tonight, possibly remaining a rain/snow mix or mainly snow in the far north towards Fond du Lac and Sheboygan. The precip will then transition back to lighter snow from north to south the remainder of the night, with light snow lingering into Wednesday.

Breezy winds are expected during this system, though the snow will be wetter, thus limiting the blowing/drifting potential. Could see some more low level wind shear tonight, though surface winds may be high enough to limit the potential for shear. Lower ceilings are likely through this event, with some lower visibilities during the periods of snowfall.

It is worth noting that there remains some uncertainty with the low track, which could impact precip types and totals if the low deviates from the current expected track.

DDV

MARINE

Issued 432 AM CST Tue Dec 9 2025

Low pressure around 29.7 inches over Lake Superior this morning has brought southwest gales to the northern half of the lake with Gale Warning in effect until 12z this morning. The winds will gradually weaken over the next few hours to below gale force.

A much stronger low around 29.2 inches will then track from Minnesota across southern Lake MI and into lower MI tonight. Southwest to westerly gales will develop ahead of the low over the southern third of the lake tonight, followed by the potential for northwest to northerly gales on Wednesday after the low passes. The northwest gales will bring more widespread gales across the southern two thirds of the lake. A Gale Warning is now in effect for the south third starting mid evening tonight and starting for the central third early Wednesday morning (11z). The brisk winds will then gradually diminish Wednesday night. A period of northwesterly gales may then return Friday night into Saturday as a strong arctic front moves through the Great Lakes region. Heavy freezing spray may develop.

DDV

MKX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056- WIZ057-WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ067- WIZ068...6 PM Tuesday to 6 AM Wednesday.

LM...Gale Warning...LMZ080-LMZ673-LMZ675-LMZ777-LMZ779-LMZ874- LMZ876-LMZ878...9 PM Tuesday to 6 PM Wednesday.

Gale Warning...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ868 until 6 AM Tuesday.

Gale Warning...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ868- LMZ870-LMZ872...5 AM Wednesday to 6 PM Wednesday.

Gale Warning...LMZ643-LMZ644...6 AM Wednesday to noon Wednesday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until noon Tuesday.

Small Craft Advisory...LMZ643-LMZ644...6 PM Tuesday to 6 AM Wednesday.

Small Craft Advisory...LMZ645-LMZ646...6 PM Tuesday to 9 PM Wednesday.