textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Additional flurries and light snow showers are expected in southwestern Wisconsin for the next few hours. - A Gale Warning is in effect for all open waters of Lake Michigan through 7 AM CDT today, and a Heavy Freezing Spray Warning is in effect early through 11 AM CDT today.

- Light accumulating snowfall will occur Tuesday night into Wednesday morning. 1 to 2 inches of snow are expected across the area, with 2 inches most likely southwest of Madison. Patchy freezing rain or drizzle is possible as snow exits.

SHORT TERM

Issued 1218 AM CDT Tue Mar 17 2026

Today through Wednesday:

Low pressure exiting into Ontario as Arctic high pressure presses into Wisconsin will lead to lowering northwesterly winds and low temperatures in the single digits along the lakeshore and near zero inland this morning. A few areas in central Wisconsin may see lows in the single digits below zero. Morning wind chills in the negative teens are expected.

Winds will shift to southerly this afternoon, bringing in warming temperatures and highs in the low 20s. Temperatures will hover in the upper teens overnight tonight as a warm frontal feature brings in light snow from west to east. As this warm front lifts into Lake Michigan late tonight into Wednesday morning, surface temperatures will rise into the 20s and an 850 mb warm nose may develop at the same time as the dendritic growth zone desaturates. Pockets of freezing rain and freezing drizzle become possible for a brief period as snow exits. Expecting 1-2 inches of snow for much of southern Wisconsin, with a light glaze of ice possible into Wednesday morning. The best chances for up to 2 inches of snow are expected from Madison westward.

Precipitation ends from west to east Wednesday morning, with southwesterly winds continuing to bring in warmer air. Highs near 40 degrees are expected.

MH

LONG TERM

Issued 1218 AM CDT Tue Mar 17 2026

Wednesday night through Tuesday:

A quick-moving shortwave will progress through southern Wisconsin Wednesday night, bringing a mix of rain and snow showers through the late overnight hours. Temperatures are expected to remain at or just above freezing, leading to no freezing rain expected. A trace of snow is possible. Precipitation tapers off into Thursday morning, and ridging returns for highs in the 40s.

Ridging looks to remain dominant through the weekend, with high temperatures in the 50s and potentially creeping into the 60s in southwestern Wisconsin by Saturday as a low pressure system propagates through southern Ontario and brings strong southerly winds to the area. A few showers are possible (~15% chance) Saturday night into Sunday as a cold front slowly progresses through southern Wisconsin. Highs in the upper 40s to low 50s are expected Sunday, with northerly winds continuing through the overnight hours and lows in the 20s. A more active pattern returns early next week as multiple shortwaves bring chances for on and off showers and cooler temperatures in the 40s.

MH

AVIATION

Issued 1218 AM CDT Tue Mar 17 2026

VFR conditions are expected through the majority of the pre-dawn hours, with a few brief pockets of MVFR snow in south-central to southwestern Wisconsin where light snow showers are lingering in narrow bands. VFR conditions are expected throughout all of the daylight hours today, with MVFR conditions returning overnight as snow progresses west to east into early Wednesday morning. Visibilities as low as 1 SM are possible within the heaviest snow, primarily along and southwest of a line from MSN to JVL. In these regions, expect 1-2 inches of snow, locally up to 3 inches. Northeast of this line, expect around an inch of snow.

MH

MARINE

Issued 1218 AM CDT Tue Mar 17 2026

Low pressure of 28.6 inches continues to exit into Quebec this morning while Arctic high pressure of 30.3 inches presses into the northern Plains. This will lead to continued gales across the open waters, and a Gale Warning is in effect through 7 AM CDT. Gales may end earlier than forecast, and a early cancellation may be sent. Even after gales end, heavy freezing spray is expected to continue. A Heavy Freezing Spray Warning is in effect through 11 AM CDT. Winds will diminish and become light and variable midday today, before shifting to become southwesterly and increasing tonight as low pressure of 29.7 inches progresses through the southern Canadian Prairies tonight through Wednesday. A weak cold front from this low will shift winds to westerly overnight Wednesday before an additional weak low tracking through Illinois shifts winds back to southerly, then northerly Thursday. Winds will remain variable through the weekend as multiple weak systems move through the Great Lakes region.

MH

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Gale Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563- LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 7 AM Tuesday.

Heavy Freezing Spray Warning...LMZ080-LMZ261-LMZ362-LMZ364- LMZ366-LMZ563-LMZ565-LMZ567-LMZ643-LMZ644-LMZ645-LMZ646- LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 until 11 AM Tuesday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 11 AM Tuesday.