textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Light snow flurries may clip far southwest WI this evening with of a dusting of snow or less.

- Light snow may occur Friday afternoon and evening for central and east central WI with little if any accumulations.

- An Arctic airmass settles in this weekend with wind chills ranging from -10F to -30F late Friday night through Sunday night. - Next week temps return to near normal with daytime temps around or above freezing by midweek.

UPDATE

Issued 959 PM CST Thu Dec 11 2025

Breaks in the clouds across central and east central Wisconsin have caused temperatures to plummet into the single digits this evening. Breaks in the clouds are patchy as the mid to upper level clouds move southeast out of the area and low level clouds develop near simultaneously. Temperatures will fluctuate a bit as clouds move in and out southern Wisconsin.

As clouds continue to clear temperatures could fall on a more broad scale tonight. Satellite shows a large area with little to no clouds upstream which leaves temperatures dependent on low level stratus. These chances are dwindling as much of the stratus is developing once the temperatures plummet as dewpoints range roughly from 10 to 2 degrees across southern Wisconsin (dewpoint depressions shrinking). The few locations that have already had falling temperatures are Sheboygan at 8 degrees and Fond du Lac at 3 degrees. This isn't entirely out of the bounds of the forecast, but temperatures will need to be adjusted downward slightly. Temperatures were lowered a few degrees across the area tonight, but most predominantly across central and east central Wisconsin.

Patterson

SHORT TERM

Issued 243 PM CST Thu Dec 11 2025

Tonight through Friday night:

Will continue to see northwesterly upper-level flow with the trough prevail across the Upper Midwest now through the weekend. This will bring periodic chances for light snow and keep temps below normal through the end of the week with high temps on Friday in the 20s and nightly lows tonight in single digits and below zero Friday night.

This evening will see an embedded shortwave trough work its way down the main trough. While the more favorable upper-level dynamics remain south and west of our neck of the woods, there still will be a glancing blow to southwest WI this evening as the surface low tracks down the lower Missouri River Valley tonight and up the Ohio River Valley into Friday. Overall expecting minimal impacts and accumulations with a dusting to generally less than half an inch for areas southwest of Madison. These chances will quickly end by 06z (midnight) tonight.

Then another lobe of mid-level vorticity is progged to works its way down the trough across the Upper Great Lakes during the day Friday. This will bring another chance (20-50%) for light scattered snow into central and east-central WI. Again will be a quick moving wave with limited accumulation of a dusting to less than half of an inch ahead and along an Arctic cold front. The slug of moisture looks confined to the northern half of the CWA, but cannot rule out seeing light snow/flurries down to the border.

Behind the Arctic front overnight Friday will then begin to see strong CAA move into the area with a building high pressure. Will see overnight low temps around zero to negative single digits and even colder wind chills ranging from -10F to -25F into early Saturday morning.

Wagner

LONG TERM

Issued 243 PM CST Thu Dec 11 2025

Saturday through Thursday:

The bitter cold temps will persist Saturday through Sunday as the main upper-level trough digs down across the Upper Midwest advecting the cold Arctic air into the region ahead of a building +1040mb surface high. Expecting single digit high temps Saturday and Sunday for inland southern WI with sub zero lows through Monday night. Given the tighter pressure gradient over WI between the building high in the northern Plains and a low pressure gradually working its way east across the eastern Great lakes, will not see much relief in bitter cold wind chills through the day Saturday ranging from -10F to around -20F before plummeting again after sunset to -20F to around -30F Saturday night into Sunday morning. Will begin to see slightly warmer wind chills Sunday afternoon as the high pushes further east with lighter winds. However still expecting overnight winds chills ranging from -10F to -20F into Monday morning. Will likely see the first extreme cold headlines of the season with this blast of bitter cold air this weekend.

Fortunately this cold snap will be brief as the trough slides east through the start of next week. Temps will begin to warm back up on Monday as the upper-level ridging begins to build across the Upper Midwest with highs climbing back into the 20s. Even milder and near normal temps are progged for Tuesday into Wednesday with NBM and other ensembles supporting around to above freezing daytime temps.

Wagner

AVIATION

Issued 959 PM CST Thu Dec 11 2025

VFR to MVFR conditions are expected through the period. Snow chances have predominately stayed to the southwest of the state this evening. A few flurries will remain possible over the next couple of hours, but not expecting much. If any flurries do occuring, mainly across the far southwest, then a dusting of snow will be possible. Mid to upper level clouds are moving southeast out of the state this evening and as the temperatures fall there will be a potential for low level stratus to develop. The stratus deck is expected to be around 1 to 2 kft. These stratus clouds will be patchy and slow moving across southern Wisconsin. Clear skies will be possible in areas where the upper level clouds clear and no stratus develops, this is most likely across portions of central Wisconsin. Clouds will return across the state Friday as a cold front approaches. The front will pass Friday afternoon into Friday evening bringing chances for snow and plummeting temperatures. There will be a potential for MVFR to IFR ceilings as the front passes. A dusting to a couple tenths of an inch will be possible. Visibilites of 2-6 SM will be possible with any snow Friday. Clouds will linger into Friday night, but ceilings are expected to slowly rise.

Light and variable winds are expected tonight into Friday morning. West winds late Friday morning will start to increase and become breezy through the afternoon. Friday night brisk northwest winds are expected and will continue into Saturday morning.

Patterson

MARINE

Issued 243 PM CST Thu Dec 11 2025

Northwest winds will continue to weaken through the evening as high pressure moves east as a low pressure tracks in from the Plains tonight and up the Ohio River Valley on Friday. Light winds overnight will gradually pick up behind the low on Friday and may be a brief window of west to northwest gust around gale force Friday night through Saturday night as a strong Arctic cold front moves through the region. However, due to brisk conditions, looking like heavy freezing spray will develop during this period as the colder airmass moves into the Great Lakes region. Then a strong high pressure will move southeast from the northern Plains and through the region Sunday and to the south early next week. Will see winds ease later Sunday, but gusty winds may return early next week behind the exiting high as temps warm back to near normal.

Wagner

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None.