textproduct: Marquette

KEY MESSAGES

- Light lake effect snow extends into the eastern UP this morning, with up to 1-2in of snow expected mainly over Alger and northern Schoolcraft counties.

- Widespread moderate to heavy snow sweeps through tonight, followed by lingering lake effect snow Friday. Gusty winds could lead to near whiteout conditions in parts of the eastern UP and the Keweenaw. Winter Storm Warnings are in effect tonight into Friday.

- A strong winter storm will track through the Great Lakes late this weekend. Uncertainty remains but there is the potential for significant impacts to the region.

DISCUSSION

Issued at 334 AM EDT Thu Mar 12 2026

Early this morning, nighttime microphysics reveals mostly clear skies for the majority of the UP. The exception is over the east- central UP, where light lake effect snow showers have been able to re-develop. This persists through the rest of the morning, with snow totals up to 1-2in expected for Alger and Northern Schoolcraft counties; lighter amounts below an inch are expected south of M-28 in Schoolcraft county, and trace accumulations may even graze eastern Marquette and Delta counties. Temperatures falling back into the teens to lower 20s this morning quickly rebound into the lower to mid 30s this afternoon with plenty of sunshine to start off. However, clouds will be on the increase by the late afternoon ahead of our next approaching winter storm.

Tonight into Friday, a quickly-moving Clipper drops through the area, possibly deepening below 990mb by early Friday morning. Robust isentropic ascent on the nose of a ~40-50kt LLJ, with plenty deep moisture and our DGZ co-located with our strongest ascent will allow moderate to heavy snow to begin to spread into the western UP around 00Z tonight. This continues to fill in area-wide by early Friday as this system continues to work into the area. There remains some uncertainty on track, as hi-res guidance favors a somewhat more northerly track (over the UP or Lake Superior by Friday morning) compared to the global models (over northern WI by Friday morning). This would have implications for the duration of our widespread snowfall, as the more northerly solution results in more of a quick hit while potentially allowing in a dry slot that could further erode away our snowfall from 06Z onwards. The more southerly solutions, meanwhile, keep us comfortably beneath the swath of steady, heavier snowfall until at least 12Z Friday. Still, significant impacts to travel, and heavy snow accumulations are expected regardless of duration. A period of widespread one inch per hour snow rates looks likely during the overnight hours, with localized lake enhancement off of Lake Michigan possibly leading to even higher rates up to 2in/hr across US-2 during the pre-dawn hours (50% chance per the href). Synoptically-driven snow starts to taper from west to east as the low makes its eastward trek over northern Lake Michigan and into the northern LP. However, blustery northerly winds developing on the backside of the exiting system will kick off a round of lake effect snow over the north and eventually NW wind snow belts the rest of the afternoon, finally tapering from west to east into the evening. Snowfall rates around 0.5in/hr will be possible in lingering LES.

As far as totals, a widespread 6-10in is expected across the UP with locally higher totals up to a foot in the higher terrain of the north-central UP and in the north-wind snow belts if the eastern UP. The Keweenaw, too, will be under the gun for totals in excess of a foot given lake enhancement throughout the event. There, expect a widespread 8-12in with a 50% chance for higher totals in excess of a foot especially over the spine. What may work against totals (in addition to the aforementioned problem of storm track) is the expected blustery winds, which may shred our snowflakes and lower SLRs. However, this presents an additional concern as blowing snow may lead to near-whiteout conditions especially over the Keweenaw and the eastern UP tonight into early Friday.

In spite of the uncertainty regarding exact snowfall amounts, with the expected significant impacts tonight into Friday, have decided to upgrade our watches to Winter Storm Warnings across the entirety of the UP.

Friday night into Saturday will bring a reprieve from the winter weather with lows in the single digits and teens and seasonable highs in the low 30s. It still appears that a significant winter storm will track through the Great Lakes late this weekend bringing a swath of one to two feet of snowfall. Ensembles seem to be converging with the low tracking through southern or central Lower Michigan, which keeps the heaviest axis of snow to the south and east of the U.P., with widespread light snow across the U.P. and areas of upslope/lake enhancement. There is the potential for strong winds with this system as well with possible blizzard conditions where the heavier snow occurs. Changes to the forecast track and details are likely as we get closer to the weekend.

Monday into Tuesday will see much colder air move into the area with highs only in the teens Monday and low to mid 20s Tuesday. CPC continues to highlight better chances for below normal temperatures and above normal precipitation for days 6-10.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 112 AM EDT Thu Mar 12 2026

Clear skies promote VFR conditions across Upper Michigan tonight and for much of the day Thursday as surface high pressure transits the region. Gusty NW winds gradually diminish to 10 kt or less through Thu morning. Winds begin to shift southeasterly ahead of the next approaching system late in the period, with the next round of snow and blowing snow spreading west to east from 00-06z Fri. This will bring IFR conditions back to the terminals Thu night into Fri. Also expect LLWS to develop at KIWD after 00z as a 50 kt low level jet arrives over the western UP.

MARINE

Issued at 334 AM EDT Thu Mar 12 2026

NW winds continue to gust up to 25-30kts through the pre-dawn hours over the eastern half of the lake, then winds fall below 20kts by mid morning. The next storm system approaches the region tonight, bringing strong winds to the lake. Southeast gales are likely tonight (80%+ chance), shifting north Friday morning. There is a chance for a few gusts to storm force (40-60% chance). Winds will shift north on Friday with gales up to 40 kt before falling below 20kt on Saturday morning. There is a potential for another winter storm to bring another round of gales Sunday into Monday (50-60% chance), though there is quite a bit of uncertainty regarding track and timing of this next system. As colder air moves into the area Sunday into Monday heavy freezing spray will develop across much of the lake.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Storm Warning from 8 PM EDT /7 PM CDT/ this evening to 2 PM EDT /1 PM CDT/ Friday for MIZ001>004-009-010-084.

Winter Storm Warning from 11 PM this evening to 5 PM EDT Friday for MIZ005.

Winter Storm Warning from midnight tonight to 8 PM EDT Friday for MIZ006-007-013-014-085.

Winter Storm Warning from 10 PM this evening to 1 PM CDT Friday for MIZ011-012.

Lake Superior... Gale Warning from 10 PM EDT /9 PM CDT/ this evening to 11 AM EDT /10 AM CDT/ Friday for LSZ162.

Gale Warning from 11 PM this evening to 2 PM EDT Friday for LSZ242-263.

Gale Warning from 11 PM this evening to 2 AM EDT Saturday for LSZ243>251-264>267.

Lake Michigan... Gale Watch from late tonight through Friday afternoon for LMZ248-250.