textproduct: Marquette

KEY MESSAGES

- A passing cold front will bring chances for rain and snow showers today, lingering into the evening.

- Lake effect snow and wind may impact the Thanksgiving holiday weekend. Travelers and interested parties should continue to monitor the forecast as details become more clear over the coming week.

- There is a 50% chance for Gale Force and 25% chance for Storm Force winds/light freezing spray on Lake Superior during the middle of next week.

DISCUSSION

Issued at 329 AM EST Sat Nov 22 2025

Early morning water vapor and RAP analysis show deep troughing digging into new England, weak ridging over the Great Lakes, and another shortwave dropping into the Northern Plains. Closer to home, stubborn lake clouds remain blanketed over the eastern UP, with mostly clear skies across the central and eastern UP. Clear skies and light winds have helped temperatures fall back quite nicely into the upper teens and 20s so far across the western half of the UP, and it would not be a shock to see temperatures fall even further into the lower teens into the pre-dawn hours. Meanwhile, temperatures may struggle to drop even into the upper 20s under the aforementioned lake clouds.

Winds back to the south after daybreak as the warm front associated with the approaching wave lifts through, allowing cloud cover to fill back in and kicking off a quick batch of precipitation. This starts off mainly as snow showers this morning, but as temperatures warm into the upper 30s and lower 40s today, expect a transition over to mainly rain showers with just a few snowflakes mixing in. Significant snow accumulations are not expected given marginal temperatures and generally light QPF. The cold front moves through late afternoon and evening, turning winds over to the NW. Model soundings, with plenty of dry air and lowering inversion heights, are not so supportive of significant lake effect. However, a little more moisture present in model soundings over the Keweenaw and north- central, and the longer fetch off of Superior into the eastern UP, will keep the potential for lake effect rain and snow showers lingering in those locations into tonight. Lake effect tapers off Sunday as a ridge begins to build over the Great Lakes once again, allowing for quiet weather into Monday. This period will feature the warmest temperatures of the week; look for highs in the 40s to and perhaps closer to 50 for some Sunday, and well into the 40s and lower 50s Monday.

Then, we face the potential for more active weather the rest of the week. Current analysis over CONUS positions an upper level low along the southern California coast. As this weekend progresses, this feature will press through the 4 Corners, ejecting into the Southern or Central Plains by Sunday night. Ridging stretches atop this feature into middle Canada ahead of a another wave digging into the Northern Rockies. Guidance is a little mixed on how or if these waves will interact over the Northern Plains, which impacts the duration and magnitude of the following lake effect event. The general idea presented in all guidance packages though suggests that synoptic rain will spread into the region Monday night and Tuesday and then transition over to lake effect snow showers in the Tuesday night to Wednesday timeframe. Main questions we're still grappling with are the position and timing of the synoptic surface low, how fast temperatures will cool Tuesday night and Wednesday, and how long the lake effect event will persist. These will all impact snow accumulations. Additionally, the position of the surface low will impact wind speeds and blowing snow potential. At the very least, latest deterministic EC, GFS, and Canadian all maintain snow showers in the northwest wind snowbelts Thanksgiving and into Friday. Through this period, the EC and Canadian ensembles currently suggest a 50-80% chance of at least 6 inches for portions of these snowbelts while keeping the south-central snow free. More clarity in this should evolve with time. For now, the recommendation for those with Thanksgiving travel plans in the Great Lakes is to continue monitoring forecasts.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1222 AM EST Sat Nov 22 2025

VFR conditions are expected into Saturday with mainly clear skies over the area. A quick moving system will bring increasing cloudiness again Saturday morning. Rain and snow showers will spread across the northern U.P during the afternoon. This cloud coverage brings a period of MVFR/IFR conditions to CMX (40% chance for MVFR, 25% chance for IFR). MVFR is also possible at SAW during the afternoon, 30% chance. Winds will be light tonight and shift southerly on Saturday. Saturday evening a cold front will push across the U.P with a low cloud deck behind the front, bringing widespread MVFR conditions to the TAF sites.

MARINE

Issued at 329 AM EST Sat Nov 22 2025

NW winds over the eastern half of the lake continue to gust to near 20kts early this morning, but are expected to continue to fall back while backing to the south after daybreak. Anticipating these lower winds to only linger into the afternoon, when pressure falls and southerlies increase with the passage of an afternoon/evening surface trough. By early Sunday morning, another shot of colder air aloft across the east will push winds to near 30kts. A weak isallobaric component may allow for northwest low end gale after midnight through around 8am, though ensemble guidance remains modest, showing only around a 30-40% chance for gales across the central and eastern portions of the lake. Have therefore held off on issuing any headlines. Any gale potential quickly falls off Sunday morning, then NW winds finally fall back below 20kts Sunday evening. Winds look to remain mostly below 20kts through at least Tuesday.

Next week, a system is expected to move through the Great Lakes. There's still a number of questions about how this event will evolve, including whether or not the surface low will deepen over the region and how quickly it will move through the region. What is certain though, is that the airmass moving in behind the system will be notably colder, which increases the likelihood of gales in the Tuesday night through Thursday night window. At this point, Storm Force Winds and pockets of light freezing spray cannot be ruled out. Given the clustering differences among the EC, Canadian, and GFS ensemble membership, there's varying degrees of potential outcomes at this point. Given this, the latest Gale probabilities near 50% and Storms near 25% make sense. As we move into next week, some of this should improve and a clarity on anticipated conditions should materialize.

MQT WATCHES/WARNINGS/ADVISORIES

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