textproduct: Marquette

KEY MESSAGES

- A low pressure system passing south of the UP through Sunday will bring system snowfall to the southern and eastern UP, with lake effect snowfall kicking up for the northern and western UP. Winter Weather Advisories are in effect for virtually all of Upper Michigan through Sunday afternoon.

- Gusty northerly to northwesterly winds expected in the wake of the low pressure. Gale Warnings in effect for the east half of Lake Superior, with wind gusts of 25 to 35 mph expected over the land.

- Light to moderate lake effect snowfall expected to continue through next week as a cooler than normal airmass resides over the UP.

- The next chance of widespread snowfall comes with a fast-hitting Clipper Low late Tuesday into Wednesday.

DISCUSSION

Issued at 408 PM EST Sat Nov 29 2025

Radar mosaic shows lake effect snowfall having fully shifted offshore over the east half of Lake Superior and light radar returns shifting north over the south-central UP, lining up with KMNM METARs showing light snowfall beginning this afternoon. This snowfall arrives ahead of a RAP-analyzed 1010mb low pressure centered over northern MO this afternoon with neutrally tilted troughing aloft lagging not far behind. This neutral tilt will limit the potential for this low to deepen like the previous one did. The path of the low is mostly certain at this point, with ensembles honing in on a track that brings the low through Chicago tonight, the Saginaw Bay Sunday morning, and to the southern Ontario/Quebec line Sunday evening. The fast-moving nature of the low will limit synoptic snowfall accumulation potential, though the cool air aloft over a still relatively warm Lake Michigan will give a lake enhancement as easterly flow will be over the south-central while the synoptic portion of the snowfall occurs. Given the additional cyclonic surface flow with the low in the region, lake effect snowfall is expected to reinvigorate this evening, first with a dominant northeast-wind band over the west part of Lake Superior and then with northerly multibands overnight becoming northwesterly by Sunday afternoon. The northeasterly dominant band will move onshore over the western UP overnight, bringing a quick burst of 0.5"/hr (30-50% chance) to 1"/hr rates (10-30% chance), though as the stronger band will be replaced by shorter-fetch bands as well as the arrival of drier air at the surface and aloft and shrinking inversion heights, so total accumulations in the west should remain sub-Warning criteria. Over the counties adjacent to Lake Superior outside of the west, orographic support will help boost the forcing. Rural high terrain areas near the Baraga/Marquette line may see snow totals up to 8 inches, though the populated areas will see around 3 to 6 inches of snowfall. Thus, the current Winter Weather Advisories look to remain on track, and while the snow totals are not extreme, this will cause some slick road conditions during a crucial holiday travel period as people return from their Thanksgiving destinations. Adding to the hazards will be the wind, which in the wake of the low will gust to around 20-30 kt, especially near the shores of the Great Lakes. This may cause some localized blowing and drifting snow, which could make corridors such as M-28 in Marquette and Alger Counties and US-2 in Schoolcraft County even more treacherous.

By Sunday evening, ridging approaches quickly from the west, bringing down the intensity and coverage of lake effect showers, as NBM QPF struggles to break 0.05"/6hr, even in the strongest forecast NW wind LES bands. LES will continue to some extent, as thermodynamic support for LES will be abundant considering 50-90% chances within the LREF ensemble of 850mb temperatures being at least -10 C or colder over around 5 C temperature Lake Superior all week. This will allow for the potential for some rare SW-wind LES over the Keweenaw Peninsula Monday, though accumulations exceeding 1 inch by Tuesday morning are only above 50% north of Laurium. Otherwise, the next system threatening to bring widespread snowfall to the UP will come with a weak Alberta Clipper low passing through northern Ontario late Tuesday into Wednesday. While snow totals look unimpressive with the trailing cold front, chances of multiple inches of accumulating NW wind LES climbs to 30-60 percent for Wednesday. Additionally, the cool NW winds behind the front will allow for Thursday morning low temperatures to fall to the single digits for much of the UP, with 20-40% chances of sub-zero lows along the MI/WI state line. Uncertainty then grows in the forecast as a high pressure takes place over much of the Midwest Thursday and ensembles have a wide range of solutions on when a low pressure might pass through the region to break up the high pressure. The CPC outlooks through at least the month of December prefer higher than normal precipitation and cooler than normal temperatures, so hopes for a White Christmas for the UP remain high.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 610 PM EST Sat Nov 29 2025

Light snow spreading into the area is beginning to drop ceilings down to MVFR already, with some drops in visibility as well. Over the next couple of hours, expect further deterioration to IFR as snowfall rates turn heavier. Snow transitions to more of a lake effect regime on Sunday, with mainly MVFR conditions and increasing north winds gusting to 20-25 kt. Drier air working in may bring an improvement to MVFR late in the forecast period.

MARINE

Issued at 408 PM EST Sat Nov 29 2025

A low pressure passing through southern Lake Michigan tonight and through Lake Huron tomorrow will kick up northeast winds to 25-30 kt over the west half tonight. As winds turn northerly and northwesterly behind the low, chances of gale force gusts to 35 kt remain around 40-60 percent for Sunday, so Gale Watches have been upgraded to Warnings over the east (though the Watch over the north- central has been cancelled as chances of gales over that zone have fallen below 20 percent). Approaching high pressure will quickly drop winds to near 20 kt Sunday evening as they become westerly and southwesterly. Monday, chances of a brief southwesterly gale are around 30 percent over the west half as the pressure gradient compresses with a Clipper Low approaching. In the wake of that low, northwesterly wind gusts ramp up to 30 kt with chances of gales around 40-60% on Wednesday. Winds fall back down to 25-30 kt for Thursday with the resumption of high pressure near the Great Lakes, though uncertainty increases late in the week into the weekend as models differ on when the arrival of the next system will be and how strong that system might be.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Weather Advisory until 1 PM EST /noon CST/ Sunday for MIZ001>006-009-084.

Winter Weather Advisory until 1 PM EST Sunday for MIZ007-014- 085.

Winter Weather Advisory until 7 AM EST /6 AM CST/ Sunday for MIZ010>013.

Lake Superior... Gale Warning from 4 AM to 7 PM EST Sunday for LSZ245>248-265.

Gale Warning from 7 AM to 9 PM EST Sunday for LSZ249-250-266.

Gale Warning from 1 PM to 7 PM EST Sunday for LSZ251-267.

Lake Michigan... None.