textproduct: Marquette

KEY MESSAGES

- A Winter Weather Advisory is in effect for Southern Schoolcraft and Luce counties where lake effect snow transitioning to system snow will bring 3-8" tonight through Tuesday morning. Highest amounts are expected closer to the Chippewa/Mackinac county borders.

- Two rounds of widespread light snow are expected early this week, the first late tonight through early Tuesday, and the second late Tuesday through Wednesday morning.

- Cooler than normal temperatures continue through this week and beyond. Low temperatures in the single digits to near zero are possible late this week into this upcoming weekend.

DISCUSSION

Issued at 342 AM EST Mon Dec 8 2025

Early morning GOES satellite imagery shows areas of clearing across the UP as ridging aloft and surface high pressure atop WI has kicked LES to the WNW snow belts. Light LES in the far eastern UP counties, mainly N Luce and Chippewa, may accumulate another inch at best before backing SW winds fully pushing bands offshore through the morning hours. Efficient radiational cooling has taken place across the central and western UP where observations at the time of writing this discussion have fallen well below zero, some, including our office here in Negaunee Township, reaching as low as -10 to -15F. Our low of -14F breaks the daily record low of -13F for December 8th. Elsewhere, single digit to teens temps are found under cloud cover or closer to the lakeshores, where the "warm" ~40F waters are keeping milder conditions.

Mostly quiet weather remains in place through this afternoon as SW flow ahead of an approaching clipper helps bring daytime temps into the upper teens and low 20s. Increased SW fetch across northern Lake Michigan will then support a developing lake effect snow band into the eastern UP this evening. CAM guidance continue to highlight modest convergence into southeastern Schoolcraft and Luce counties with the QPF bullseye moreso planted along the county borders with Chip/Mack. Underneath this band, hazardous travel conditions may be seen as 00z HREF probability suggests 60-80% chance for snowfall rates >0.5/hr and winds gusts 25-30 mph. As the clipper shortwave draws nearer to the UP, widespread system snow will then begin to spread west to east late tonight into early Tuesday, grazing the UP with a widespread 1-3". Given the quick hitting nature of the clipper, confidence in heavy snow >3" is rather low (<30% chance), however, if sneaky fgen banding combined with moderate to high SLRs 15-20:1 can linger in the west and central UP, locally higher amounts >3" may be realized. In the east, SW flow and lake enhancement from Lake Michigan will make reaching amounts >3" a bit easier. Have opted to hoist a Winter Weather Advisory for S Schoolcraft and Luce counties from this evening through Tuesday morning for amounts between 3-8" as lake effect transitions to system/lake enhanced snow. The highest amounts will likely seen closer to the Chip/Mack borders by Tuesday morning.

A quick reprieve in snow is expected Tuesday morning/afternoon aside from some light lake effect snow showers across the NW wind snowbelt. The next clipper shortwave quickly follows late Tuesday through Wednesday morning, this one associated with a sharper upper level wave and a deeper surface low pressure reflection. Model consensus, while not completely in line yet, has come into better agreement on the track of this clipper, sliding it through central WI down into lesser MI. With this track, the heaviest snowfall axis is displaced south of the UP, providing another round of 1-3" for us. Ensemble probabilities for amounts >3" by Sunday morning continue to highlight 30-50% along the WI/UP border. While snowfall amounts look to remain on the lower end across the northern tier of the UP, a sharp increase in northerly winds 30-40 mph and lake effect/enhanced snow may make for some travel hazards.

Light lake effect for the N to NW wind snowbelts is likely to continue through the latter half of this week and coming weekend. Operational models and their ensemble counterparts hint at a stronger clipper coming through the Great Lakes next weekend, but diverge on its overall progression, timing, and strength. The colder than normal pattern remains in place through seemingly the rest of the month!

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 614 AM EST Mon Dec 8 2025

MVFR conditions continue to linger at CMX early this morning, but there should be improvement to VFR after daybreak. Elsewhere, VFR is prevailing at IWD and SAW and will continue to until snow moves in this evening. At that point, conditions will begin their deterioration to MVFR again and eventually IFR between 04-06Z as snow showers intensify at all TAF sites. In addition, southwest winds will increase with gusts up to 20 kts.

MARINE

Issued at 342 AM EST Mon Dec 8 2025

W to NW winds 15-25 kts back to the SW today ahead of an approaching clipper. SW winds will increase to 25-30 kts with occasional gales to 35 kts possible. Guidance continues to be on the fence on widespread gale potential for eastern Lake Superior tonight through Tuesday morning with various ensemble probability ranging from only 20% to 80%. Model soundings only support mixing down occasional gales, thus we are opting to cancel the ongoing Gale Watch. Should gales be realized a short fused headline may be needed. Winds fall below 25 kts as the system pulls away late Tuesday. Lighter winds don't last long as a second stronger clipper is set to move across Wisconsin through Wednesday, quickly increasing NE to N winds between 25-30 kts early Wednesday morning. Here, the chance for gales to 35 kts sits at around 50%. Heavy to moderate freezing spray is possible as wave heights grow 5-10 feet. Behind this departing system Wednesday afternoon, N to NW winds fall to 25 kts or less and remain that way through the mid to late week. Guidance is hinting at the return of stronger winds next weekend and will continue to be monitored.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Weather Advisory from 4 PM this afternoon to 7 AM EST Tuesday for MIZ007-014.

Lake Superior... None. Lake Michigan... None.