textproduct: Marquette

KEY MESSAGES

- A major winter storm continues to impact the Upper Peninsula through this evening. Heavy snow and high winds are resulting in widespread blizzard conditions, with visibility near zero at times. Blizzard warnings remain in effect for most of the UP through this evening.

- Widespread moderate to heavy snow this morning changes to lake effect snow across the N to NW wind snow belts later this morning, with the heaviest snowfall rates over the eastern UP (along and north of M-28) after sunrise.

- The heaviest additional snowfall amounts through this evening will be across the higher terrain of the north-central UP and eastward along and north of M-28. In those locations, expect totals to peak at around 10-15" with around a 50% chance for totals up to 20" in the far eastern UP.

- Across the rest of the western and south-central UP, expect widespread totals around 3-6" through this evening.

- Gale and Storm Warnings continue into tonight. Storm force gusts have become common across the lake, with gusts in excess of 60kts observed at times.

DISCUSSION

Issued at 437 AM EST Mon Dec 29 2025

Early this morning, a deep surface low of 984mb is analyzed over central Lake Huron, with a steep pressure gradient over the Upper Peninsula as 1038mb high pressure is centered over the Northern Plains. Widespread moderate to heavy snowfall persists across the central and eastern UP, heaviest across the north-central and eastward (generally along/north of M-28) given orographic and lake enhancement. Snowfall rates of around 1-2in will be common in these areas the rest of the night, increasingly becoming confined to the far eastern UP towards 12Z as inversion heights begin to lower over the western and central UP. Meanwhile, the back edge of this "system" snowfall is already reaching the western UP as the storm continues to pull away. However, with steep CAA behind this exiting system (850mb temperatures already dropping to near -15C over the western UP) and blustery N to NW winds, lake effect snow is already kicking off in the west. Lake effect snow persists the rest of the day across the north-central and eastern UP, but may taper off over the west by the evening as drier air finally wins out.

As far as additional snow totals: by sunrise, the north-central and eastern UP is looking at a widespread 6-10in of synoptically driven, and lake/orographically enhanced, snowfall. Several more inches of snow are expected in those locations as we head into the daytime hours, highest in the far east with more moisture in soundings and a longer fetch over Superior. Lighter totals of around 2-4in are expected across the south-central and western UP tonight, with additional lighter totals of around 1-3in during the daytime. This leaves us with a widespread 3-6in of snow in the western and south- central UP from early this morning through this evening, and around 10-15in over much of the norht-central and east. The highest potential totals, upwards of 20in, will be over far eastern Upper Michigan across Luce county.

Winds have also really picked up tonight with a strong 45-60kt LLJ directed over the area and model soundings showing us easily mixing into that layer. Winds are gusting to 30-40mph across much of the UP, and stronger gusts to 40-50mph are becoming more common across the northern UP (especially nearer to Superior). Some 60mph gusts are not out of the question. Gusty winds and heavy snow have lead to blizzard conditions across much of the UP, with near zero visibility at times. The exception continues to be those WI-bordering counties of the south-central UP, where we struggle to quite achieve blizzard criteria. Still, visibility continues to drop below a mile at times with moderate to heavy snow and gusty winds leading to blowing snow. Gusts slowly decrease from west to east this afternoon and evening as winds aloft begin to slacken. This, in addition to snowfall tapering off, will allow for our winter headlines to fall off from west to east this afternoon and evening. Until then, Blizzard Warnings and Winter Storm Warnings remain in effect for most of the day across the entire UP.

Lakeshore Flood Advisories remain in effect for counties along Lake Superior where waves 15-20 feet may create flooding and beach erosion hazards through this evening.

Light LES lingers in the far eastern UP into tonight, with light snow totals of around an inch possible. A quick-hitting clipper moves back in on Tuesday, resulting in a bit more light widespread snow, but perhaps more importantly, heralds a reinforcing shot of Arctic air for the New Year holiday. LREF mean shows 850 mb temps in the low -20s (C), which is around the 10 percentile. This would result in wind chills well below zero for the New Year's Holiday, along with northwest flow lake effect snow. Temperatures finally begin to moderate into next weekend as a ridge starts to build into the region, though westerly LES may linger into Saturday.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1221 AM EST Mon Dec 29 2025

A significant winter storm will bring blizzard conditions at times to the U.P overnight into the morning hours with LIFR and VLIFR conditions at the TAF sites. North winds will gust to 50kt late tonight into Monday morning and then weaken to around 30-40kt by late in the TAF period. Widespread moderate to heavy snow will diminish during the morning hours but lake effect snow showers and blowing snow will continue to bring IFR conditions through much of the late morning and afternoon, especially at CMX and SAW. MVFR conditions are expected late in the TAF period as lake effect snow showers diminish and wind gusts fall to around 30kt, reducing blowing snow impacts to visibility.

MARINE

Issued at 437 AM EST Mon Dec 29 2025

Unusually strong low pressure currently over Lake Huron will continue to track into Quebec through today. Northerly gales and storm-force winds have developed, highest across central Lake Superior, and persist through the early afternoon before slowly falling back below gale-force later today into tonight. Heavy freezing spray is expected, with significant wave heights in excess of 20ft possible over east-central Lake Superior (70-90% chance) with 12-20ft elsewhere. Wave heights slowly decrease this evening. After gales end tonight, a reinforcing shot of Arctic air across the lake is expected to result in northwesterly gales and heavy freezing spray at times Tuesday night to the end of the week, especially over the central and eastern lake.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Blizzard Warning until 4 PM EST this afternoon for MIZ001-003- 004-084.

Lakeshore Flood Warning until 7 PM EST this evening for MIZ001.

Blizzard Warning until 1 PM EST /noon CST/ this afternoon for MIZ002-009.

Lakeshore Flood Advisory until 7 PM EST /6 PM CST/ this evening for MIZ002-003-009.

Blizzard Warning until 7 PM EST this evening for MIZ005>007- 013-014-085.

Lakeshore Flood Warning until 10 PM EST this evening for MIZ005-006.

Lakeshore Flood Advisory from 8 AM this morning to 10 PM EST this evening for MIZ007.

Winter Storm Warning until 3 PM CST this afternoon for MIZ010>012.

Lake Superior... Storm Warning until 10 PM EST this evening for LSZ242>251- 263>267.

Gale Warning until 10 PM EST /9 PM CST/ this evening for LSZ162-240-241.

Heavy Freezing Spray Warning until 10 PM EST /9 PM CST/ this evening for LSZ162-240>251-263>267.

Lake Michigan... Storm Warning until 10 PM EST this evening for LMZ221-250.

Heavy Freezing Spray Warning from 2 PM this afternoon to 10 PM EST this evening for LMZ221.

Gale Warning until 10 PM EST this evening for LMZ248.