textproduct: Marquette

KEY MESSAGES

- Widespread snow is expected across the U.P today. Winter Weather Advisories and Winter Storm Warnings are in effect.

- A period (2 to 4 hours) of moderate to heavy snow and blowing snow with winds gusting to 35 mph are expected mid-morning into the early afternoon over the western and central U.P. making for difficult driving conditions at times.

- Several hours of heavy snow and blowing snow with winds gusting to 35 mph are expected over the eastern U.P. with up to 8 inches of accumulation late morning through the afternoon. This will result in very difficult driving conditions with localized whiteout conditions possible, especially along the US-2 corridor east of Rapid River.

- Lake effect snow will develop late tonight into Wednesday for the western UP and the north half of the eastern UP, with moderate snow accumulation and locally reduced visibilities. Additional Winter Weather Advisories will likely be needed.

- Highs in the upper 30s in the east to mid 40s in the west return on Friday before well below normal temperatures return for this weekend.

DISCUSSION

Issued at 205 AM EST Tue Feb 24 2026

Early morning water vapor shows a broad, low-amplitude ridge over the southwestern US, while a vigorous, compact shortwave trough is pushing east-southeast across the Canadian Prairies. Strong upper level jet max modeled at up to 160 kt at 300 mb is located between these features. The shortwave will continue to amplify as it digs into the upper Great Lakes through the day. Ahead of the trough, strong isentropic lift is forecast as the low to mid-level height gradient tightens. That forcing will be enhanced by poleward jet exit region dynamics, with the end result being a period of snow from mid-morning into the early afternoon central/west, and late morning through the afternoon in the east. Southerly winds will be quite gusty at up to 30-40 mph for a couple hours during the snow, which will result in low visibility due to falling and blowing snow. The winds will likely be strongest just prior to the onset of snow, especially in favored downsloping areas, which could lead to lower visibility issues even before the snowfall begins, due to recent fluffy snowfall. Cross section analysis reveals a strong frontogenetic circulation on the back side of the eastward-moving precip shield, with a conditional symmetric instability (CSI) signature noted. This accounts for the north-south enhanced band of snow now developing over southern Manitoba and depicted in simulated reflectivity that will likely result in the heaviest snowfall rates near or briefly in excess of an inch per hour. This signature is moving quickly with a bit of a dry slot building in behind it, so these heavy rates should be fairly limited in duration (likely no more than an hour or so of 1"/hr rates for the central and west). In the east, the 1"/hr rates will last longer (possibly 3-4 hours) due to the low-level flow aligning off of Lake Michigan allowing for lake enhancement, as well as relatively stronger synoptic-scale forcing. These heavier rates look to occur roughly 2-6 pm. Of particular concern are open areas such as the portion of US-2 east of Rapid River along Lake Michigan, which could see periods of whiteout conditions during this timeframe. Although totals will not be excessive by UP standards, a Winter Storm Warning remains in effect for the eastern UP due to the expected heavy snowfall rates and their implications for hazardous travel conditions during peak travel times.

There will be a brief lull in the snowfall this evening before northwest flow lake effect picks up late tonight. Parameters look pretty good for some heavier bands of lake effect snow with inversion heights around 2 km in the west to possibly as high as 3 km in the east (per NAM soundings). Wind gusts of 20-30 mph will result in continued blowing snow issues in favored areas especially near the lakeshore. Additional winter headlines will likely be needed late tonight into around midday Wednesday for portions of the western UP and roughly along/north of the M-28 corridor in the east.

High pressure builds in briefly late Wednesday into Wednesday night, ending the LES. Another period of light snow is possible on Thursday as a brief shot of isentropic lift develops in the return flow on the back side of the high, but it does not look impactful. A warm sector moves into the region Friday resulting in one seasonably mild day as a strong clipper moves eastward across Ontario. The warmth will be short lived, however, as the clipper's front passes through Friday night. There is a moderate to high probability of 850 mb temps getting lower than -20C by Sunday morning (-1 to -2 sigma), so this will set up a seasonably cold weekend and start to March.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 620 AM EST Tue Feb 24 2026

Strong S'rly wind gusts pick up this morning across the terminals as a strengthening Clipper low moves into Lake Superior later today. IWD will probably struggle to get gustier winds mixed to the sfc this morning, and is expected to see some LLWS for the first couple hours of the TAF period. Associated with the Clipper is a band of moderate to heavy snowfall as S'rly wind gusts get up to 30 to 40 mph; expecting to see some BLSN at CMX and SAW late this morning through early this afternoon as the intense snowfall and gusty winds will blow around the fluffy snowfall coming down as well as anything on the sfc. Thinking there will be a 2-4 hour window today where airport mins will be realized at CMX and SAW today due to the intensity of the snow band associated with the Clipper and BLSN before a strong dry slot mostly shuts everything off behind it. Behind the passage of the Clipper low, we may see a quick-lived weakening in the winds before they turn WNW'rly and pick up this evening through the overnight hours, bringing light to moderate LES over IWD and CMX tonight. We may also see BLSN over IWD tonight; expect it to return to CMX tonight as the WNW'rly winds will be gusty (up to 30-35 mph possible at times). Expect MVFR cigs over IWD and CMX tonight, with SAW potentially returning to VFR provided the cloud deck scatters out.

MARINE

Issued at 257 AM EST Tue Feb 24 2026

Strong southerly winds develop this morning with gales to 40 kt over the east half of the lake and heavy freezing spray for the majority of the lake. Winds diminish from west to east this afternoon evening, but increase again late tonight as colder air moves in on the back of a departing low. A brief period of 35 kt gales is expected late tonight into early Wednesday afternoon over the east, with heavy freezing spray expected to redevelop over most of the lake in the same timeframe. A second Gale Warning has been issued, and additional Heavy Freezing Spray Warnings will likely be needed.

The probability of gales is less than 20% from late Wednesday through early Friday. Southerly winds increase during the day Friday as a strong clipper crosses Ontario with 40% gale probabilities, increasing to 70% Friday night into early Saturday behind a strong cold front. There is a 30% chance of storms to 50 kt during this time as well, with heavy freezing spray likely once again.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Weather Advisory until 3 PM EST /2 PM CST/ this afternoon for MIZ001>005-009-084.

Winter Storm Warning from 10 AM this morning to 7 PM EST this evening for MIZ006-007-013-014-085.

Winter Weather Advisory from 10 AM this morning to 4 PM CST this afternoon for MIZ010>012.

Lake Superior... Heavy Freezing Spray Warning until 1 PM EST this afternoon for LSZ242>248-263>265.

Gale Warning until 1 PM EST this afternoon for LSZ243>248-264- 265.

Heavy Freezing Spray Warning until 4 PM EST this afternoon for LSZ249-250-266.

Gale Warning until 7 PM EST this evening for LSZ249-250-266.

Heavy Freezing Spray Warning until 7 PM EST this evening for LSZ251-267.

Gale Warning from 10 AM this morning to 7 PM EST this evening for LSZ251-267.

Gale Warning from 1 AM to 1 PM EST Wednesday for LSZ265-266.

Lake Michigan... Gale Warning from 10 AM this morning to 4 PM EST this afternoon for LMZ248-250.