textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Another round of light snow is expected late this morning and afternoon, with amounts ranging from a dusting to an 1 inch. The best chances (20-40%) for snow amounts around/exceeding an inch will be for areas from Sauk county through Rock and Walworth counties.

- Cannot rule out a brief window of freezing drizzle ahead of the onset of the snow as well on the back edge, bringing minor impacts.

- Single digit temps and wind chills of 5 below to 15 below zero are expected overnight New Years Eve into New Years Day.

UPDATE

Issued 936 AM CST Wed Dec 31 2025

Bumped high temps up a couple degrees for today given latest observations and short term models. Otherwise, the forecast looks on track, with light snow pushing in from the northwest by late this morning. Still looks like a brief opportunity for freezing drizzle as the precip moves in, but most locations upstream are starting as snow.

DDV

SHORT TERM

Issued 405 AM CST Wed Dec 31 2025

Today through Thursday:

Another round of light snow is expected today across portions of southern WI as a mid-level shortwave trough to digs down across the Upper Great Lakes region through the day while a cold front pushes down from the nort-northwest to southeast. May be a brief window on the leading edge of the snow transition to see some light freezing drizzle before the DGZ saturates this morning. However confidence remains on lower side as uncertainty remains on how quickly it takes to saturate along with warmer/above freezing temps creeping from the southwest this morning.

Otherwise, expecting this snow activity to begin late morning across the Wisconsin River Valley and spread southeastward through the afternoon and into the early evening. Snowfall amounts will once again be on the low side given QPF less than a tenth of an inch and SLR of 12:1-16:1. The better slug of Pacific moisture is progged across areas along and southwest line from WI Dells to Kenosha where another 0.5-1.0 inch of snow is likely given the better alignment of a small swath of low- level WAA and the bands of 925-850mb frontogenesis pairing with the edge of the higher PWATS (around 0.5 inch). Would not be surprised to see locally higher swath of 1-2 inches within this area from Sauk County through Rock/Walworth county given the tendency for banded precip to over achieve. Meanwhile, while some models do have this snow activity spreading into east- central WI, overall trend limits this activity up that way with a dusting to under an additional half an inch. On the back side of the snow this evening could be another brief window for freezing drizzle as things dry out aloft, but less certain as models hint at a narrow/brief window. Lastly, timing of this activity will coincide with the afternoon/evening commute this New Year's Eve, so some impacts tor travel will be possible.

Behind the cold front expecting temps to fall as we ring in the New Year with temps around the teens after sunset and falling into the single digit as 2026 rolls on into southern WI. Breezy northwest winds will accompany this colder airmass and will result in even colder wind chills bottoming out between -5F to -15F into New Year morning. Otherwise, New Year Day will be drier, but on the chilly side with high temps ranging from around 20F to the mid teens.

Wagner

LONG TERM

Issued 405 AM CST Wed Dec 31 2025

Thursday night through Tuesday:

The colder trend is expected to continue through the end of the week with below normal temps as high pressure builds from the Dakotas and into the Great Lakes. While it is looking drier with the high pressure, there are a few models that hint a small ripple of mid- level vorticity working across the area with another slug of Pacific moisture and a weak cold front on Friday. So cannot completely rule out a quick burst of light snow.

Temps remain on the cool side Saturday as the high pressure weakens and as model continue to delay the ridge from moving into our neck of the woods. Temps then gradually warm Sunday into the start of next week as the upper-level ridge builds in and kicks the surface high east. However the pattern does continue to hint at becoming more active Sunday night with a series of mid-level disturbances traversing the Upper Midwest into the start of next week with a more prominent wave Later Tuesday.

Wagner

AVIATION

Issued 936 AM CST Wed Dec 31 2025

Light snow will move in from the northwest late this morning into the afternoon. There is a small chance for a brief period of freezing drizzle as the precip begins, though many upstream obs are starting as snow. The bulk of the snow will fall during the afternoon hours, winding down by around 00Z. Visibilities may drop as low as 1/2 - 1 SM at times, especially along/south of I-94. Ceilings will drop to around 1 kft, likely briefly dipping below that at times during the more moderate snowfall rates. Snow to liquid ratios of 10-15 to 1 are expected, with totals up to 1.5 inches. Westerly winds this morning will increase out of the northwest this afternoon as a cold front drops through, with gusts up to 25 knots during the afternoon and early evening.

Skies will clear out this evening into tonight along with decreasing winds as high pressure builds in from the northwest. Clouds will increase during the day tomorrow, with a chance for a little light snow during the afternoon hours.

DDV

MARINE

Issued 405 AM CST Wed Dec 31 2025

Northwesterly winds prevail across the Lake today as strong low pressure meanders back into the Hudson Bay region. Extending off of this low is a secondary cold front that is expected to slide down across the Lake through the day with increasing northwesterly gusts behind it into this evening. Cannot rule out seeing a few gales across the far northern portions of Lake Michigan this evening, but this window looks brief. Thus have held off on any gale headlines at this time. However, with the colder airmass and gusty winds behind the cold front, moderate freezing spray will be a concern overnight into New Years Day. Then winds slowly lessen through Thursday as high pressure builds down across the Upper Midwest Thursday through the weekend.

Wagner

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 3 AM Thursday.