textproduct: Marquette

KEY MESSAGES

- Lake effect snow will develop late tonight into Wednesday for the western U.P. and the north half of the eastern U.P., with moderate snow accumulation and blowing snow resulting in reduced visibilities.

- Highs in the upper 30s in the east to mid 40s in the west are expected on Friday. A strong cold front on Friday night will bring much colder air back into the area along with a period of strong winds, particularly over the Keweenaw and near Lake Superior. Widespread blowing snow is possible in the Keweenaw with the potential for wind gusts up to 50 mph Friday evening/night.

DISCUSSION

Issued at 231 PM EST Tue Feb 24 2026

Early this afternoon satellite water vapor imagery and model analysis showed a 500mb low tracking through northern Ontario with troughing extending south into northern MN. Strong lift along an advancing cold front was generating a band of moderate to heavy snow. Radar observations showed an intense band of snowfall preceding a cold front moving through the central U.P. Sfc observations of 1/4 mile vsby were reported earlier today at IWD and CMX with this band. It was breezy with southerly wind gusting 30-35 mph, especially in the typical downslope areas along Lake Superior. Temperatures were in the teens and twenties.

Through the remainder of the afternoon the band of moderate to heavy snow will continue to move east with snow rates up to one inch per hour. It will last 2 to 3 hours at most locations in the central U.P. As it moves through the eastern U.P. it will be enhanced by moisture off of Lake Michigan. This will result in a longer period of heavy snow, 4 to 6 hours. Snowfall totals will be 2 to 4 inches over the west and central with 4 to 7 inches in the east. The heavy snow rates combined with blowing snow will create poor visibility, down to 1/4 mile at times.

The band of snow will exit the eastern U.P. early this evening and winds will shift to the northwest. CAA in the low to mid levels will result in increasing lake induced instability with inversion heights to 6 kft. Dry air advecting into the region will limit lake effect snow intensity and coverage in the western U.P., with notable inverted-v type soundings. However, moderate snow rates are expected over the terrain due to orographic enhancement. Better moisture and a longer fetch will result in moderate to perhaps heavy snow showers in the northern counties of the eastern U.P overnight. Drier air will work its way into the east as well Wednesday late morning which should help slowly weaken the snow intensity through the day. Overall snow amounts this evening through Wednesday afternoon are in the 2-4 inch range for the western U.P. and 3-6 inches in the eastern U.P., particularly northern Schoolcraft, eastern Alger and Luce counties. Issued a Winter Weather Advisory to follow up the Winter Storm Warning in the east. Also issued advisories for the Keweenaw due to the combination of snow and blowing snow.

Temperatures will fall into the single digits tonight with wind chills as low as -10F over the interior. Used a blend of CAMs for wind gusts tonight into Wednesday morning as the NBM was much to light given the strong low level winds and caa resulting in steep low level lapse rates.

Expect lake effect snow to diminish Wednesday night with winds becoming light. Temperatures will fall into the single digits below zero. With light winds, clearing skies and snow cover temperatures could fall well below guidance and wouldn't rule out interior locations reaching -15 to -20F. Will not stray from guidance at this time but adjustments could be needed with proceeding shifts.

Temperatures will be warmer on Thursday, widespread mid 20s and as warm as the low 30s in the far west. A weak clipper could bring a period of light snow during the day but less than a half inch of snowfall can be expected. Friday will be warmer yet with highs reaching into the low 40s before turning sharply colder behind a strong cold front pushing through Friday night. There are concerns for blowing snow, especially near Lake Superior and over the Keweenaw, with strong winds possible behind the front. NBM guidance has a 75% chance for winds above 40mph over the Keweenaw late Friday evening. GFS bufr soundings show several hours of wind gusts over 50 mph behind the front. Limiting factors will be warmer temperatures during the day on Friday which could help create a bit of a crust on the snow and widespread lake effect snow isn't expected to accompany the winds.

Highs over the weekend will be in the teens with low in the single digits below zero Saturday night.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1214 AM EST Wed Feb 25 2026

Northwest wind lake effect prevails during the 6Z TAF period. Given the wind direction, no vis restrictions are expected at SAW and mainly MVFR cigs are expected until late this afternoon/evening when skies scatter out. A period of low-end VFR or SCT MVFR is possible this morning, but timing was inconsistent among the guidance and confidence in occurrence was too low to include. MVFR/IFR is expected at IWD/CMX through this morning before conditions improve. IWD should return VFR late this afternoon when a SCT cloud deck returns. CMX may linger in MVFR into tonight depending on how long lake effect is able to persist.

Otherwise expect WNW to NW winds gusting between 20-30 kts, strongest at CMX. Wind gusts taper down through early this afternoon. This may result in blowing snow at CMX through this morning.

MARINE

Issued at 231 PM EST Tue Feb 24 2026

A strong clipper low will move across northern Lake Superior and into eastern Ontario tonight. Southerly winds will fall below gale force and then shift northwest to 30kt this evening. A period of gales is expected over the east central part of the lake with a few gusts to gale force in the west. Heavy freezing spray will accompany the winds as colder air also spreads across the lake. A ridge of high pressure will build in Wednesday night into Thursday with northwest winds falling below 20 kt and shifting southwest. Southerly winds will ramp up to 30 kt on Friday ahead of a deepening clipper low that will move through Ontario Friday night. A strong arctic cold front associated with the low will move across the lake Friday evening. Behind the front high end gales are likely (60% chance) over the eastern half of the lake with a 40% chance for storm force gusts. Heavy freezing spray will also accompany the winds. Winds will diminish through the day on Saturday with light winds on Sunday as a strong high pressure moves overhead.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Weather Advisory until 1 PM EST Thursday for MIZ001-003.

Winter Weather Advisory until 7 PM EST this evening for MIZ006- 007-085.

Lake Superior... Heavy Freezing Spray Warning until 7 AM EST /6 AM CST/ this morning for LSZ162.

Heavy Freezing Spray Warning until 10 AM EST this morning for LSZ242-263.

Heavy Freezing Spray Warning until 4 PM EST this afternoon for LSZ243>248-264-265.

Heavy Freezing Spray Warning from 4 AM early this morning to 1 AM EST Thursday for LSZ249>251-266-267.

Gale Warning until 1 PM EST this afternoon for LSZ265-266.

Lake Michigan... None.