textproduct: Marquette

KEY MESSAGES

- Light snow is expected Thursday night into Friday, with a moderate probability of light freezing rain also possible in the counties bordering Wisconsin. Snow totals are expected to remain below 4 inches, except in the Keweenaw and eastern UP, where there is a 40- 60% chance of exceeding 4 inches. Untreated roadways may become slippery.

- A Gale Watch is in effect for eastern Lake Superior on Thursday night into Friday.

- Temperatures will average above normal through Saturday, then become sharply colder with lake effect snow Sunday into early next week.

DISCUSSION

Issued at 309 AM EST Wed Dec 24 2025

Early this morning surface analysis showed high pressure building into the Upper Great Lakes as the low that brought breezy conditions and a trailing cold front through the area yesterday moved east into Quebec. Temperatures had fallen into the upper teens and twenties. Satellite imagery showed lake effect clouds over much of the U.P but inversion heights remained low inhibiting precipitation development.

Through this weekend the temperature roller coaster will continue as multiple shortwaves move through the area bringing warm air north ahead of the waves and cold air surging south their wake. The next few waves will be stronger than what we've seen over the last several days and it appears a much stronger front will arrive for Sunday into Monday bringing the potential for strong winds and lake effect snow back into the area.

The cold air will begin to retreat again today. Warm air advection associated with the warm front could be enough to set off a few snow showers. Moisture and lift look fairly limited but there could be enough for a brief period of light snow and/or sleet as the warm front pushes through. The front will again drop south tonight bringing colder air back into the area. Behind the front inversion heights over the lake will get near 3kft which should be enough for at least lake effect flurries near Lake Superior and possibly a few light snow showers by Christmas morning. There could also be a brief period of freezing drizzle in the higher terrain of Marquette County as moist upslope flow could lack temperatures cold enough for ice nucleation. Temperatures for Christmas Day look to be near normal, in the 20s across the U.P. Lake effect flurries will again be a possibility through the morning into the early afternoon as north flow, turning northeast, continues over Lake Superior. A stronger shortwave will approach the area late in the day bringing increasing precipitation chances, especially for Christmas night into Friday morning. Ensemble and ECMWF/GFS deterministic guidance has trended a bit further south with this heaviest precipitation, with NBM probabilities for snowfall of 4"+ around 50% over much of the northern and eastern U.P and as high as 60% over the Keweenaw. Model guidance also shows the possibility for rain or freezing rain as warmer air overrides the colder air, mainly closer to the MI/WI border where NBM probabilities of at least 0.01" of ice accumulation are 30-50 percent Thursday night into Friday.

It becomes milder Saturday with a high probability of highs above freezing everywhere as ridging finally makes better inroads. However, medium range ensembles and deterministic models continue to indicate a strong low pressure system developing over Ontario in concert with a midlevel low cutting off over the upper Great Lakes. This would usher in a much colder airmass with accumulating lake effect snow in at least the NW flow belts for Sunday into Monday.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 137 PM EST Wed Dec 24 2025

Mostly VFR conditions are expected to continue through the day today; however, MVFR ceilings will move in overnight and will persist on Thursday morning. Otherwise southerly winds will become northerly overnight behind a passing surface trough.

MARINE

Issued at 309 AM EST Wed Dec 24 2025

Southerly winds to 20-25 kt will develop today as high pressure slides east of the lake. The southerly winds are short lived, with high pressure building to the north resulting in winds shifting to north/northeasterly Wednesday night into Christmas Day at 20-30 kt.

As the high shifts east, another period of southeasterly gales is possible late Thursday night into Friday morning (50-70% chance), along with snow. Gale watches have been issued for the central and eastern part of the lake for the aforementioned period. A stronger low pressure is expected to develop Sunday into Monday, moving westward north of the lake. There is rather good confidence (70-80%) in gales on the back of this system despite the long lead time, with a moderate probability of storm force gusts and heavy freezing spray Sunday into Monday.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Warning from 1 AM to 1 PM EST Friday for LSZ244-245-264- 266-267.

Lake Michigan... None.