textproduct: Marquette

KEY MESSAGES

- Mixed precipiation changes to light snow across the west half this morning. Light rain/snow showers possible elsewhere.

- Temperatures continue to come in above average through early next week. Highs will be in the upper 30s to 40s on Saturday, then rising into the 50s for Sunday and Monday.

- Another system will bring potential for accumulating snow to the U.P. mid next week, but forecast confidence is low at this time.

DISCUSSION

Issued at 307 AM EST Sat Mar 7 2026

Our much-anticipated batch of thunderstorms is finally reaching the south-central UP on the nose of a 40-50kt 850mb LLJ analyzed ahead of the surface low currently centered over central WI. MUCAPE of around 500j/kg is analyzed over the area, and storms currently moving over Menominee county and across the Bay have a healthy amount of lightning on them while IR imagery shows embedded higher cloud tops. That said, though reflectivities of 60dbz are common closer to the UP border, I suspect that this may be due at least in part to some bright-banding; freezing levels from tonights soundings at GRB and MPX are at around 8-9kft, and the GRB radar is sampling such reflectivities at at least 7kft. Still, some steadier, heavier downpours are not out of the question, and would be unsurprised if we were to hear of a hail report from any night-owls. Given such strong winds aloft, a stronger wind gust would be possible as well, but even storms that have moved right over available surface stations have yet to produce any significant gusts.

As far as rain totals? Thus far, MRMS is showing accumulations generally around a quarter to half an inch, and in spite of the potential for radar overestimates, this is at least in line with available (if unofficial) surface observations throughout northern WI. Would therefore expect similar totals across the south-centrla and eastern UP the rest of the night, with higher embedded totals where any heavier downpours can occur. While this is not expected to present a flooding risk, will still note the potential for some localized ponding/water issues given our lingering snowpack potentially leading to poor drainage conditions.

This initial batch of storms continues to move northeastward through the central and eastern UP over the next few hours, making an exit around 10Z. However, hot on its heels is our next batch of precipitation as the cold front (currently over western WI and western Lake Superior) sweeps through. While precipitation starts off as rain in the west, a change over to snow is expected by 12Z. However, soundings still support a brief period of light freezing rain somewhere between 09-12Z as a warm layer persists aloft before the entire column ultimately cools below freezing. Generally expect no more than a glaze of ice and 1-2 inches of snow along the Keweenaw and Porcupine Mountains before precipitation comes to an end by early afternoon. Lingering precipitation will also change over to light snow in the east as precipitation winds down, but expect minimal snow accumulations of an inch or less across the central and eastern UP through the afternoon. The passing cold front, and increasing winds, is also expected to help scour out our lingering fog, which is dense at times early this morning.

Sunday and Monday continue to look warm and mostly dry within zonal flow as a pair of lows pass well to the north across Ontario. Look for daytime highs to climb into the 50s in many locations as overnight lows stay above freezing area-wide Sunday night. Still keeping an eye on the next system Tuesday into Wednesday as another wave ejects out of the South Plains and potentially phases with a northern stream trough during the middle of next week. There is still quite a bit of ensemble spread regarding strength, placement, timing of this feature, albeit with at least a general consensus keeping the track south of the UP in the vicinity of the Lower Midwest and Lower Great Lakes into Wednesday. This track would tend to favor a snowier solution for the UP - potentially with some lake enhancement given a northeasterly wind direction. NBM probabilities for at least a tenth of an inch of ice remain in the low single digits; meanwhile, probabilities for greater than 4" of snow over parts of the UP in this time frame have jumped as high as 25-40%. Will continue to monitor in the coming days. Otherwise, expect temperatures to trend cooler with daytime highs generally near or below freezing from Tuesday through mid week.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 658 AM EST Sat Mar 7 2026

Low pressure is lifting through the region this morning with a cold front currently working across the central UP. West of the front, a narrow zone of mixed precip and snow is impacting CMX/IWD. Meanwhile, VLIFR fog remain at SAW. Through the rest of the morning, expect this zone of winter precip to continue at CMX/IWD through at least 16z before lifting out of the area. Lingering LIFR/IFR cigs will gradually lift to MVFR/VFR by 18z. At SAW, thinking vis should improve shortly above airport mins behind the passing cold front, as nearby obs/webcams are showing. Otherwise, improving conditions are expected with a prob30 for light showers just before 18z. Gusty NW winds 15-20 kts are expected at all sites this afternoon.

MARINE

Issued at 307 AM EST Sat Mar 7 2026

Low level moisture will continue to result in areas of fog over the water, potentially dense at times early this morning. Winds shift northwesterly from west to east this morning as a cold front moves through; a few gales to 35 kt are possible over the eastern half of the lake from mid-morning through the early afternoon. Widespread southwesterly gales of 40-45 kt are likely (60-90% chance) tonight into Sunday as the pressure gradient strengthens in response to a low pressure tracking through Ontario. Gale warnings go into effect late tonight through Sunday afternoon. Winds fall to 25kt Sunday night with the next chance for gales quickly returning Monday as another low pressure system tracks through Ontario. Yet another chance for gales mid next week as low pressure moves into the Lower Midwest.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Warning from 1 AM EST /midnight CST/ to 11 AM EST /10 AM CST/ Sunday for LSZ162.

Gale Warning from 1 AM to 5 PM EST Sunday for LSZ242>244-263- 264.

Gale Warning from 5 AM to 5 PM EST Sunday for LSZ245>251- 265>267.

Lake Michigan... Dense Fog Advisory until 7 AM EST this morning for LMZ248-250.