textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Periods of scattered light snow showers expected after dark this evening through tonight. Only a few tenths of an inch additional snow expected, but the rapidly falling air temps this evening could lead to slick spots / re-freeze of wet pavement.

- Mild to start the workweek, with the warmth peaking on Tuesday (highs in the mid 40s).

- The next low pressure system brings 20-35% light rain chances on Tuesday, followed by 10-35% light snow chances Wednesday.

SHORT TERM

Issued 300 PM CST Sat Jan 10 2026

Tonight through Sunday night:

The 500mb centroid of the low pressure system and two of it's associated vorticity maxima will pass over our region this evening / tonight, with this afternoon's sunshine and cold air aloft working together to sharpen surface to 800mb lapse rates upwards of 8 C/km ahead of it. This will cause snow showers to develop over our region this evening, primarily between 5 PM and 10 PM CST, with potential for additional scattered snow showers between then and 5 AM CST Sunday. New snow accumulations of a trace to a half inch expected across the region, with even the upper percentile estimates falling shy of 1 inch.

The existing snow pack (on the ground) is too wet / slushy to blow around, hence despite the 25 to 35 MPH west to northwest wind gusts expected this evening through Sunday morning, we are not particularly concerned with blowing and drifting snow. The aforementioned snow showers tonight will produce lighter / powdery snow which could be suspended in the air, but the expected amounts (0.5") are not much to work with. Temperatures fall deep into the 20s this evening, reaching around 20 degrees flat for an overnight low. Hence, there could be some slick spots on pavement where lingering puddles / moisture are found, as well as from the trace snow accumulations.

Low clouds will linger into Sunday morning, though the lack of any forcing for ascent suggests only flurries would be possible after ~5 AM CST. Gusty northwest winds continue into Sunday morning, dissipating towards mid day as the low clouds scatter apart. High temps right around the freezing mark Sunday afternoon, with continued dry weather and a low in the mid 20s Sunday night.

Sheppard

LONG TERM

Issued 300 PM CST Sat Jan 10 2026

Monday through Saturday:

500 mb cluster analysis generally shows a deepening trough over the eastern part of the country Tuesday into Wednesday, with an amplified ridge over the west. The eastern trough then deepens a bit to the west over the Ohio River Valley, with the amplified ridge more over the west coast. This should generally result in northwest flow at 500 mb over the Upper Midwest during the week.

Dry conditions with mild temperatures look to occur Monday into Monday night, with some warm air advection developing Monday night ion increasing south to southwest winds. A cold front passes southeast through the area later Tuesday, with warm temperatures ahead of the front as the southwest winds linger. This may melt any lingering snowpack across the area. There are mainly 20 percent chances for light rain ahead of the front Tuesday into Tuesday evening, though forecast soundings are rather meager with deep moisture.

Cold air advection then kicks in toward 12Z Wednesday, as gusty northwest to north winds develop with a tight pressure gradient. Forecast soundings are more robust with low level moisture developing with steep low level lapse rates later Tuesday night into Wednesday. There is some differential CVA with passing vorticity maxima during this time as well. Kept some 20 to 30 percent chances for light snow/snow showers during this period.

More seasonable temperatures are expected on Wednesday with the cold air advection, and these values should linger through the rest of the week. There are indications from ensembles of low pressure shifting southeast through or north of the area mainly Thursday night into Friday night. The ensembles show some potential for light snow to occur with this system. Kept 30 to 50 percent chances for light snow during this period for now, and this may be the next decent chance for some accumulating snow.

Wood

AVIATION

Issued 300 PM CST Sat Jan 10 2026

A brief window of VFR continues for the middle of this afternoon, with scattered light snow showers and 1,500 to 3,000 ft MVFR cloud ceilings expected to move in after sunset, with new snow accumulations of a few tenths of an inch (worst case scenario currently less than 1 inch). 20-30 KT northwest wind gusts are expected this evening through Sunday morning, dissipating by mid day Sunday. The scattered snow showers dissipate by 5 AM CST Sunday, with the MVFR ceilings hanging on for several more hours, possibly until mid day.

Sheppard

MARINE

Issued 300 PM CST Sat Jan 10 2026

Low pressure around 29.7 inches will develop over northern Lake Michigan by this evening, and will deepen to around 29.5 inches as it shifts into eastern Ontario by later tonight.

Expect west northwest winds to increase into tonight, as high pressure around 30.6 inches builds across the central high Plains. Northwest gales are expected, and a Gale Warning remains in effect for later tonight into Sunday morning.

A Small Craft Advisory remains in effect for the nearshore waters of Lake Michigan into Sunday afternoon for gusty west to northwest winds. A few gale force gusts may occur later tonight into Sunday morning.

Winds gradually ease Sunday evening into Monday. South to southwest winds will return by Tuesday, ahead of another low pressure system around 29.3 inches, which may move to north of Lake Michigan through the middle of next week.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Gale Warning...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675- LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876- LMZ878...3 AM Sunday to noon Sunday.

Gale Warning...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...3 AM Sunday to 9 AM Sunday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 3 PM Sunday.