textproduct: Marquette

KEY MESSAGES

- Ongoing winter storm continues to bring wintry mixed precipitation to much of the UP through Friday morning. A changeover to rain is expected tonight across the far south and eastern UP. Sleet and freezing rain persist in the west half before precipitation diminishes from south to north altogether overnight.

- Another winter storm is expected to bring mainly freezing rain to the UP Friday night into early Saturday morning. There is a 50-70 percent chance of significant ice accumulations exceeding a quarter inch in the central and western UP away from the immediate lakeshores, with amounts of a tenth to a quarter inch expected elsewhere. Very difficult travel conditions are possible, with increasing likelihood of tree damage and power outages where the heaviest icing occurs.

- Gales of 35 to 40 kts diminish overnight, but are possible again this weekend with the secondary winter storm.

DISCUSSION

Issued at 308 PM EDT Thu Apr 2 2026

Early afternoon GOES satellite imagery reveals a deep negatively tilted trough lifting northeast into the Upper Mississippi Valley. A large baroclinic leaf is present reaching into the Great Lakes amidst strong isentropic ascent and warm air advection. So far, a hodgepodge mess of winter precip types have been observed across the UP with mainly snow in the Keweenaw, sleet and freezing rain elsewhere, and rain/mix in the south and far east. Luckily, road temperatures have come in slightly above freezing, leading to minimal travel impact reports in our neck of the woods. Still, the combination of sleet and freezing rain mix will keep untreated roads and surfaces slick. As the surface low draws closer to the UP and the elevated warm nose warms a few degrees, freezing rain is expected to be the predominant precip type across the central and eastern UP this afternoon and evening. Surface temperatures have largely remained a few degrees cooler than the NBM, which originally had temperatures warming above freezing for the eastern half of the UP by now, however temps are hovering just below or around 32F. Thus, freezing rain accumulation is still anticipated on elevated surfaces. While confidence is low on significant impacts, the combination of freezing rain and breezy east winds may lead to power outages and tree branch damages. The probability for an additional 0.1" of ice accumulations are high (80-100%) from the interior west and central UP through the far east, however, the probabilities fall near the lakeshores and portions of Menominee/Delta counties where a few degree warm up through the rest of the afternoon may curtail further impacts. Chances for an additional 0.25" fall significantly everywhere, though there remains a 40-80% chance near the inland Marquette/Alger county border. Through tonight, the low pressure lifts through the eastern UP, gradually changing precip to all rain (with a few rumbles of thunder possible) across the east half before shutting off precip altogether from south to north. Wintry mix in the west half tapers off though lingering light wrap around/upslope snow showers are possible across the west half.

Friday will be a brief reprieve from impactful weather, with brief ridging building in from the north. This will keep temperatures on the cool side, with most areas getting at least a few degrees above freezing, except for the higher terrain of the north-central UP and Keweenaw. Highs look to reach the upper 30s to low 40s over the southern half of the UP, which should help to melt some of the lingering ice on the trees.

The next period of impactful weather will be already beginning Friday night. This system is broadly similar to today's system, although there are some key differences. Similar to the first system, the second system will have a cutoff low over the Plains ejecting into the Great Lakes, impinging upon a downstream ridge. Copious Gulf moisture will be in play for the second system as well, with PWATs in the 0.75-1.00 inch range, which is +1 to +3 sigma. However, the second system looks to occlude quicker than the first system, with the occlusion process occurring to our southwest. As a result, warmer air is projected to be overhead when the precipitation begins, decreasing snow and sleet chances and increasing freezing rain and rainfall chances. The antecedent high pressure is in more of an ideal location to feed cold/dry air into the system at low levels, over Hudson Bay with the second system as opposed to southeast Canada for the first system. It is expected that most of the freezing rain occurs Friday night, meaning that accretions won't have to fight the April sun angle. This raises the risk of impacts to travel compared with today's system, although it is difficult to know how road temperatures will respond. There is some uncertainty with a potential midlevel dry slot and how quickly that will act to cut off the steadier precipitation Saturday morning as well. Overall, expect >50% probability of greater than a tenth of an inch of ice over most of the UP Friday night into Saturday morning, except for Keweenaw County, which should be deeper into the colder air, seeing more snow and sleet, and except for possibly portions of the UP adjacent to Lake Michigan due to the possibility of temperatures remaining above freezing with winds off the lake. There are 50-70% probabilities of significant accumulations greater than 0.25" flat ice over the central and western UP away from the immediate lakeshore Friday night into Saturday morning. Winds do not look excessively strong, but still elevated at 10-15 kt, which will increase the risk of downed branches and power outages somewhat. Impacts will be exacerbated by any lingering icing from Thursday's event, which would be most likely in the high terrain of the north- central where high temperatures Friday will be stuck near the freezing mark under mostly cloudy skies. Temperatures should gradually rise above freezing in the interior late Saturday morning into the afternoon.

The AI versions of the GEFS and EPS ensembles, which were further south/east with the low track, have trended north/west, which increases confidence in icing rather than snow/sleet for most of the central/western UP.

In the wake of this system, colder than normal temperatures look to prevail under broad troughing through early next week. There is a moderate chance for light accumulating snow on Monday.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 149 AM EDT Fri Apr 3 2026

Light snow showers, or a snow/sleet mix, continues to lead to MVFR or IFR visiblity at IWD and CMX so far tonight, with IFR/LIFR ceilings. Meanwhile, SAW has actually seen visibility improve to MVFR, but with freezing drizzle expected to develop later tonight courtesy of upsloping off of Superior, LIFR or VLIFR visiblity and ceilings become more likely. All sites improve to IFR into Friday morning, and possibly MVFR into the afternoon with a brief break in wintry precipitation. This reprieve does not last long on Friday as another system approaching from the southwest brings a second round of wintry mix and flight restrictions, beginning at IWD closer to 06Z Saturday.

MARINE

Issued at 308 PM EDT Thu Apr 2 2026

East gales of 35 to 40 knots persist across most of the lake by this afternoon as a low pressure approaches the region. With the sfc low moving through northern Lake Michigan this evening, expect the winds to become more northeasterly this evening before weakening behind the low to northerly winds of 20 to 30 knots late tonight into Friday. While winds are looking to weaken close to 20 knots by Friday afternoon, expect another Colorado low to lift towards the Upper Great Lakes Friday and Friday night. Because of this, expect the winds to once again increase from the northeast to east across the lake, mainly from the far west first starting late in the afternoon on Friday; as of now, there is a 40% chance that low-end gales will be seen across the lake late Friday night into Saturday morning. While we may see the winds slacken a little during the day Saturday as the center of the low approaches, once the low lifts through the Straits (or Lower Michigan) Saturday evening, expect winds to back to the northwest and north, with over a 50% chance for low-end gales possible Saturday night into Sunday morning (mainly over the eastern half); some areas of freezing spray may return with the stronger winds Saturday night into Sunday morning. As high pressure ridging returns to the area on Sunday, expect the winds to dial back down to 20 knots or less by the evening hours. That being said, another shortwave low dropping down over the lake Sunday night into Monday morning may bring northerly winds of 20 to 30 knots back across the lake behind it on Monday.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Storm Warning until 8 AM EDT this morning for MIZ001>005-084.

Winter Storm Watch from this evening through Saturday morning for MIZ001>005-009>011-084.

Winter Storm Watch from late tonight through Saturday morning for MIZ006-007-012>014-085.

Winter Weather Advisory until 1 AM CDT early this morning for MIZ009>011.

Lake Superior... Gale Warning until 2 AM EDT /1 AM CDT/ early this morning for LSZ162-263>267.

Lake Michigan... None.