textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Light snow overspreads the area late this afternoon into this evening. Patchy freezing may mix in at times this evening into tonight. Additional waves of snow showers will affect the area Friday morning, then periodic chances for snow/snow showers will continue through the weekend.

- Below-normal temperatures continue this weekend through the beginning of next week. Coldest temps and wind chills expected Sunday through Tuesday, and may approach Cold Weather Advisory criteria at times.

UPDATE

Issued 947 AM CST Thu Jan 15 2026

Forecast remains on track through today, with light winds slowly shifting to southwesterly this afternoon as high cloud cover increases. Expecting highs in the low to mid 20s. Early evening still appears to be the most likely timeframe of snowfall banding developing across the area, moving west to east into the early overnight hours.

MH

SHORT TERM

Issued 234 AM CST Thu Jan 15 2026

Today through Friday Night:

Winds are decreasing across the area early this morning as high pressure builds in from the west. Temperatures will fall a few more degrees through daybreak, with lows bottoming out in the upper single digits and low teens. Highs today will only reach the low to mid 20s.

Warm advection ahead of the next clipper will begin to overspread the area late this afternoon. This is expected to generate an area of light snow, though there continue to be questions about how quickly this precipitation will be able to overcome a substantial dry layer in the low levels. Some model guidance has the column saturating as early as mid afternoon along and west of I-39/90, but this seems rather fast given both the depth and magnitude of the dry layer. Early evening seems more likely, with several bands or areas of snow/snow showers transiting the region from west to east.

Heading into the late evening and overnight, guidance suggests a few more substantial pockets of mid level dry air may move across the forecast area, resulting in a loss of cloud ice at times. Lift in the low levels is not substantial, but low level moisture may be deep enough at that point to result in pockets of freezing drizzle between bands of snow. Currently, the freezing drizzle potential looks most likely between about 9 PM and midnight, and again between 3 and 8 AM on Friday. Confidence is low in this occurrence, however.

Temperatures are expected to rise through the night tonight due to the persistent warm advection, reaching the upper 20s by daybreak Friday, and the low to mid 30s by mid day Friday.

Winds will pick back up mid day into Friday afternoon with the arrival of another Arctic front, with temperatures rapidly falling during the late afternoon and evening hours. Additional areas/bands of snow will be possible with the front.

Boxell

LONG TERM

Issued 234 AM CST Thu Jan 15 2026

Saturday through Wednesday:

Synopsis: Mean upper troughing will stay entrenched across the western Great Lakes Saturday through the first half of next week. Embedded shortwaves & affiliated surface frontal passages will support periods of light snow across southern Wisconsin, with the daytime hours Saturday and Sunday into Sunday night being the currently favored time periods for precipitation. The aforementioned series of surface frontal passages will help to reinforce an Arctic air mass across the western Great Lakes Sunday through at least the first half of next week. Sunday through Tuesday night currently appears to be the coldest time frame. Global deterministic & ensemble guidance hints at additional snow potential by mid-week next week as the upper jet stream attempts to migrate north into the western Great Lakes, though forecast uncertainty remains high.

Saturday: A round of light snow is possible (~20-40% chances) as an upper shortwave & surface front cross southern Wisconsin. Latest probabilistic guidance indicates that most accumulation would be light (<30% of 1"+ in most spots) but non-zero (>70% of 0.1"+ areawide). Combined with breezy to at-times gusty northwest winds, will thus be monitoring trends for possible travel impacts in the coming forecasts.

Sunday through Wednesday: Will be watching for another round of light snow potential (~15-30% chances) Sunday into Sunday evening as another shortwave & surface front move through the area. Some uncertainty remains regarding the precise time frame period favored for snow, with timing windows being refined in coming forecasts. The Sunday/Sunday evening frontal passage will reinforce an already chilly air mass in place across southern Wisconsin, allowing well below-normal temperatures to continue through the first half of next week. Sunday through Tuesday are currently favored for the chilliest conditions, when deterministic and ensemble guidance shows the coldest 850 mb temperatures of the period moving through the western Great Lakes. Current forecast from the NBM suggests that daytime highs will remain in the single digits and teens during this window, with wind chills remaining below zero in most locations from Sunday afternoon through Tuesday. While current probabilistic guidance indicates low (20% or less) potential for cold weather headlines across most of southern Wisconsin during this window, will be monitoring forecast guidance closely over the coming forecasts. With the current forecast from the NBM showing overnight wind chills in the -10s, only minor downward trends would push overnight wind chills to near Cold Weather Advisory criteria during the Sunday through Tuesday time period. Will continue to refine in coming forecasts.

Quigley

AVIATION

Issued 947 AM CST Thu Jan 15 2026

VFR conditions continue into early this evening, light northwesterly winds turning to become southwesterly. Ceilings will lower to MVFR as snow develops across the region this evening, with visibilities as low as 2 SM expected. Snow will taper off from west to east late this evening, with a few snow showers and patchy freezing drizzle with IFR ceilings then expected through the remainder of the overnight hours. Snow will regain dominance into the morning hours, but snow showers are expected to be more scattered in nature. Ceilings will begin to recover to MVFR into Friday morning, with winds shifting to become westerly Friday morning as well. Gusty northwest winds and a return to VFR ceilings Friday afternoon.

MH

MARINE

Issued 234 AM CST Thu Jan 15 2026

Winds will continue to decrease across the open waters today as 1020 mb high pressure moves across Lake Michigan. Low pressure of 998 mb will build into the upper Mississippi River Valley this evening, resulting in increasing southwesterly winds across the waters. Winds will trend westerly on Friday as the aforementioned area of low pressure moves across Lake Michigan. 25-30 knot gusts are possible tonight through Friday afternoon, though widespread gale potential is low at this time. Generally west to northwesterly winds and periods of 25-30 knot gusts will continue through the day Sunday.

A cold front is forecast to cross Lake Michigan at some point Sunday night into Monday morning, bringing increasing northwesterly winds to the open waters. There is increasing potential for gales late Sunday night into at least Monday afternoon, particularly across the southern half of Lake Michigan. Winds will decrease on Tuesday as high pressure builds into the northern Great Plains.

Moderate freezing spray will remain a concern through Sunday. Following the frontal passage Sunday into Monday, gusty winds and even colder air will result in the potential for widespread heavy freezing spray.

For the nearshore waters, a Small Craft Advisory continues through mid morning today. Another Advisory will likely be needed tonight and Friday.

Boxell/Quigley

MKX WATCHES/WARNINGS/ADVISORIES

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