textproduct: Marquette

KEY MESSAGES

- A phasing Clipper low brings a wintry mix of precipitation to the area today. Up to 2 inches of snow is possible in the Keweenaw as well as ice amounts up to a tenth of an inch (greatest in the higher terrain of Marquette County).

- Patchy fog is possible over Lake Superior today.

- Another system arrives late Wednesday, bringing the potential for accumulations of snow and/or ice through Friday morning, though exact values are uncertain.

- Northeast to easterly gales up to 40 knots are possible over Lake Superior Thursday and Thursday evening.

- Chances of a Colorado Low passing through the area late Friday through the weekend are increasing, potentially bringing a third round of mixed wintry precipitation types.

- Daily high temperatures near/above freezing and chances of rainfall will cause snowfall and runoff to gradually raise river levels this week.

DISCUSSION

Issued at 237 AM EDT Tue Mar 31 2026

As a Clipper low phases with a Colorado low over the Great Lakes this morning, radar imagery is showing the U.P. mostly precipitation- free as the dry slot of those lows moves overhead. With temperatures generally being at or above freezing so far this morning, expect mostly rainfall across the area until the cold front of the phasing lows moves through today. However, with some of the observations hanging around freezing in the interior north central, west, and Keweenaw today, we could see some freezing rain at times up to a tenth of an inch. Thus, while we look to stay below Winter Weather Advisory criteria for freezing rain today, a SPS may need to be issued in the future in order to highlight potentially slick conditions in spots. As for the Keweenaw, with colder temperatures aloft, thinking the precipitation type will be snowfall most likely; overall, some spots could see an inch or two, with maybe a trace of ice. Once the cold front moves through, we could see the transition over to light lake enhanced snow showers over the north wind snow belts late today through tonight. However, with high pressure ridging quickly building in behind the cold front, expect snow accumulations of less than an inch over the north wind snow belts tonight into Wednesday morning before the showers end by Wednesday afternoon as the high pressure ridging crests overhead.

Don't expect the calmer conditions on Wednesday to last all that long as another shortwave low (currently over the Great Basin this morning) develops over the Plains late Wednesday before lifting into either Upper Michigan or northern Lake Michigan late Thursday. Because of this, we may see some precipitation start filling into the area from the south late in the day Wednesday and continue into Thursday night. As of right now, models have continued to trend the track of the low further west. Because of this, chances for snowfall have generally decreased across the area, but chances for mixed wintry precipitation and rainfall have increased. Therefore, we may see a tenth or two of ice over most of the area and a few inches of wet snowfall as the low pressure approaches, with a changeover to rain very possible over the south central and east Thursday. Will continue to monitor this situation; as for now though, confidence isn't quite high enough to issue a Winter Weather Advisory for this event yet. As the low lifts into northern Ontario on Friday, expect the precipitation to wrap-up.

Another low pressure system is increasingly likely to impact the U.P. late Friday into this weekend. As of right now, confidence in the exact precipitation types for this event are pretty low as they will be dependent on the temperatures of the mid-to-lower levels of the atmosphere behind the previous low and the track of this third system. However, with the track of the previous low moving further west, the chances for mixed wintry precipitation and rainfall are increasing at the expense of snowfall chances; will continue to monitor this as this could create impactful ice conditions for the Easter holiday weekend. Cooler temperatures are expected behind this third low pressure system to start out next week.

One final note worth mentioning on this forecast: U.P. rivers are slowly rising from the recent gradual snowmelt that has been seen across the region from our warm temperatures over the past week and a half. With generally above freezing temperatures during the daytime hours and the high sun angle continuing this gradual snowmelt trend over the course of the next several days, expect the local rivers to likewise slowly rise over the same time span.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 751 AM EDT Tue Mar 31 2026

Widespread IFR/LIFR conditions through at least late afternoon and possibly into this evening as a disturbance moves through the U.P. Visibility restrictions at both CMX and SAW are occuring due to overspreading snow and upslope flow/low level moisture. 70% precip chances will be concentrated over CMX, but IWD and SAW will also be impacted by rain/freezing rain, which was best highlighted with tempos this morning. As confidence wanes a bit this afternoon in precip coverage, though, chose to trend toward PROB30s at CMX and SAW to show snow and rain chances. As mentioned above, look for improvement to MVFR by Wed 00Z, but do not expect any improvement beyond that this TAF period.

MARINE

Issued at 252 AM EDT Tue Mar 31 2026

Northeast to east winds of 20 to 30 knots continue over Lake Superior this morning as a Clipper low continues phasing with a Colorado low over the Great Lakes before they both head towards Ontario and the St. Lawrence Seaway. As this occurs, there may be some patchy fog that forms over the lake at times. Once the cold front moves through today though, expect the fog to progressively clear out and for the winds to back towards the north, eventually becoming 20 to 25 knots over the eastern lake this evening before weakening to 20 knots or less late tonight/early Wednesday morning thanks to high pressure ridging quickly moving in.

However, don't expect the calmer conditions to last all that long as a Colorado low lifts from the Central Plains towards Lake Superior Wednesday night through Thursday. Therefore, expect the winds to begin picking up over the western lake from the northeast and east Wednesday afternoon to 20 to 25 knots. The winds become easterly and gust up to 20 to 30 knots by Wednesday night before potentially increasing to northeast to east gales up to 40 knots Thursday as the low approaches the lake. Because the chance for gales exceeds 50% across most of the lake, decided to hoist up a Gale Watch for the entire lake Thursday through Thursday evening. As the low passes into northern Ontario by Friday morning, expect the winds to become more northerly and slacken to 20 to 30 knots, eventually becoming 20 knots or less for a few hours late in the day on Friday. But a third low pressure system lifting from the Plains towards the region looks to increase winds from the northeast and east again late Friday into Saturday; as of the time of this writing, the chance for gales of at least 34 knots stands at around 30% for Saturday.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Watch from Thursday morning through late Thursday night for LSZ162-240>251-263>267.

Lake Michigan... None.