textproduct: Marquette

KEY MESSAGES

- Another round of light to moderate snowfall today brings 1-3 inches of snow to the northern and western UP, with some locations between Ironwood and Ontonagon (as well as the rural high terrain of Baraga and Marquette Counties) reaching near 4 inches.

- Banded snowfall today may create highly variable road conditions and rapid visibility drops, which could catch post-holiday travelers off-guard.

- Dry weather Tuesday before active weather resumes for the back half of the week into the weekend. Rain will be the dominant precipitation type, which in combination of highs above freezing could cause some rivers to continue to slowly rise.

DISCUSSION

Issued at 313 AM EDT Mon Apr 6 2026

Early morning RAP analysis shows a weak surface trough over Lake Superior ahead of a fairly subtle but distinct shortwave along the Manitoba/Ontario line. KMQT radar returns show some spots of weak reflectivity that have lead to periods of light snow showers in some METAR reports, but otherwise fairly benign conditions over the UP.

Today, showers return to the region as the aforementioned shortwave rotates around the upper trough over Hudson Bay. CAM guidance generally returns more showers to the region around 12Z this morning. Cool air surging in with the background cool northwesterly flow will give the showers a lake enhancement boost, and then with winds becoming pure northerly in the wake of the surface trough, pure lake effect snow showers are forecast. The best forcing looks to be with the lake effect regime, however, the better moisture and lapse rates will be with the earlier showers. This mis-alignment of ingredients has lead to a minor downtrend in the forecast snow totals, especially in the Keweenaw and the east. The higher snow totals near 4 inches look to impact the Ironwood metro area and the Porcupine Mountains as well as Baraga and Marquette Counties north/east of US-41, with the remainder of the western UP and Lake Superior counties seeing 1-3 inches by 06Z Tuesday. While snow totals are frankly not much to write home about, the occasional moderate-to-heavy snow showers in banded form along with gusty winds up to 30 mph will bring some 50-70% chances of visibility falling to half a mile or less at times (per the HREF). This will make for travel conditions (visibility and road slickness) highly variable over short to medium distances, which could catch post-Easter holiday travelers off guard. Will elect to hold off on any products for now, but should webcam trends match hi-res visibility output, some targeted SPS's could be necessary to warn travelers of these conditions.

Tonight, the coolest air of the forecast period will settle over the area as lake effect showers diminish. NBM low temperatures are as low as 5 degrees in the interior west, with lows in the teens along the shores of the Great Lakes. Stout high pressure to near 1035 mb then establishes itself over the Upper Great Lakes Tuesday, bringing the driest day of the forecast period to the region (from a "chance of precipitation" perspective). This kicks off a warming trend in the high temperatures, with most of the UP breaking freezing on Tuesday and the proceeding days seeing many high temps in the 40s and even in the 50s/low 60s by the end of the weekend.

The break in active weather is brief. A trough that is currently over the Gulf of Alaska will pivot through the Canadian Rockies by Tuesday afternoon, becoming positioned just upstream of the Upper Great Lakes by Wednesday afternoon. This system is expected to bring some Pacific moisture as well as establish at least a weak Gulf connection as it passes, providing ample moisture for rain to occur. The Euro ensemble shows two low clusters by 15Z Wednesday, one over the Sioux Falls, SD region and another straddling the North Dakota/Canada border. These low clusters then combine north of Lake Superior by 06Z Thursday. Rain totals by Thursday morning look to be in the quarter inch (30-60% chance) to half inch (up to 20%) range. Uncertainty then grows significantly as spread increases drastically, however the general pattern looks to continue to be rainy, including conditions over the Southeast to Southern Plains being more conducive to advect more Gulf moisture to the Upper Midwest. Attention will turn quickly to hydrology in this period as the snowpack has not only persisted, but has retained much of the liquid precipitation (freezing rain and rain) of recent as well as being reinforced by the recent (and will be reinforced by upcoming) wet snow/sleet. Should warm and moist southerly winds help snowmelt in addition to heavy rain occur (CPC highlights a moderate risk for heavy rain for the 13th and a slight risk for the 14th), flooding will be a concern, though spread is so high at this point that any details will be muddy at best. For now, just something to monitor in the outlook.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 145 PM EDT Mon Apr 6 2026

Snow showers are ongoing across the U.P. as a quick moving disturbance transits Upper Michigan this afternoon, bringing mainly MVFR conditions with intermittent bouts of IFR at area terminals. Snow showers taper off from west to east 21-00z, bringing an improving trend towards VFR as surface high pressure builds in for the remainder of the TAF period. N-NW winds gusting to 25-30kt this afternoon will diminish through this evening, becoming light and variable tonight into early Tue.

MARINE

Issued at 313 AM EDT Mon Apr 6 2026

A weak disturbance moving over the lake today will bring an approximately 6-hour window of northerly gale force winds today, first in the morning to around noon in the west-central and then the late morning to early afternoon for the east half of the lake. A short-fused Gale Warning will be hoisted for these conditions. These winds will drive waves of up to 8-11 ft and the cool Canadian air will combine with these waves to create a moderate to heavy freezing spray risk, of which a Heavy Freezing Spray Warning is already in effect for today.

High pressure will drop wind gusts below 20 kt by early Tuesday morning, ending the increased waves and freezing spray. Relatively benign conditions will then persist until early Wednesday morning, when southerly to southeasterly winds bring around 50% chances of gales to the east half of the lake. Gale chances fall to around 30% with the westerlies in the wake of the system Thursday. Active weather then continues into next weekend, but uncertainty in the details is high.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Heavy Freezing Spray Warning until 8 PM EDT this evening for LSZ243>245-248>250-264>266.

Gale Warning until 2 PM EDT this afternoon for LSZ244-245.

Gale Warning until 6 PM EDT this evening for LSZ248-251-265- 267.

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

Heavy Freezing Spray Warning from 5 PM this afternoon to 2 AM EDT Tuesday for LSZ251-267.

Lake Michigan... Gale Warning until 8 PM EDT this evening for LMZ221-248-250.