textproduct: Marquette

KEY MESSAGES

- Elevated fire weather conditions continue across much of the UP this afternoon and evening as winds continue to gust to around 20- 25mph with relative humidity falling into the lower to mid 20% range.

- There is a High swim risk along the beaches of Schoolcraft county late this afternoon through the evening; breezy conditions and choppy waters may lead to a Moderate to High swim risk there again Saturday.

- Chances for light rain showers return Saturday and Sunday, followed by mainly dry weather early next week.

DISCUSSION

Issued at 207 PM EDT Fri May 22 2026

Afternoon RAP analysis has high pressure centered over the Ontario/Quebec border, extending ridging westward into the Great Lakes. Broad troughing is analyzed across the Plains. Also apparent on satellite and RAP analysis is a compact surface low over the Dakotas, as well as another shortwave moving up the Mississippi basin at the base of the parent trough. In advance of both features, high cirrus is streaming into the Great Lakes, though the UP largely remains clear at this time. Under sunny skies, temperatures are rising into the lower to mid 60s across much of the area, apart from where southeasterly winds are onshore (that is, the Lake Michigan shorelines and the eastern portions of the Keweenaw). There, temperatures are struggling to break out of the 50s. Meanwhile, dewpoints are mixing out quite nicely into the lower to mid 20s across much of the interior of the UP, with RH in turn dropping into the 20-25% range or lower. This, combined with breezy conditions as SE winds continue to gust to near 20-25mph, will keep in elevated fire weather concerns through the rest of the afternoon. Gusty winds are also leading to choppy waters particularly over the Lake Michigan shorelines/nearshores of Schoolcraft county as well as east of the Keweenaw. A Beach Hazards Statement is in effect for the beaches of Schoolcraft county.

Attention then turns to the troughing pivoting from the Plains, moving over the Upper Midwest/Great Lakes late tonight and Saturday. The more rigorous shortwave over the Northern Plains looks to swing northward through MN and into the Manitoba/Ontario border region, while the southern shortwave tracks into the Ohio Valley and eventually the Lower Great Lakes. These features both bring weak low pressure systems with them, but the best lift remains outside the CWA. Still, weak isentropic ascent may be enough to produce some showers, and soundings are moist enough for some light accumulations Saturday through Saturday night. Probabilities for at least 0.25 inches of rain only peak at around 15-30% over the far western UP, with most of the UP looking to pick up totals below a tenth of an inch.

A trailing shortwave trough on Sunday yields a 15-30% chance for showers and weak thunderstorms with a few hundred J/kg of MUCAPE available, likely less than 500 J/kg (50% chance greater than 500j/kg in the south-central), and bulk shear struggling to reach 25- 30 kts. Another weak shortwave ripples through Monday, while a more moist, unstable airmass develops with as much as 1000j/kg of CAPE and up to 30kts of bulk shear. The ingredients are thus present for some decent convection...but forcing for development is questionable. Additional chance PoPs on Tuesday are a result of a clipper system to the north, but shear drops off to 25 kts or less. Then high pressure develops, favoring dry weather into the latter part of next week. Expect highs to warm back into the 70s to mid 80s for most early next week, cooler 60s by the lakeshores. Lows rise into the mid 40s to 50s. Forecast confidence quickly falls off by late next week as models struggle to resolve a closed low that develops over the west CONUS.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 159 PM EDT Fri May 22 2026

VFR continues through most of the 18Z TAF period as high pressure slowly shifts away from Upper MI. Two low pressure systems lifting to the Great Lakes from the Plains late in the period straddle Upper MI to the northwest and southeast on Saturday. This lowers cigs, bringing SAW down to MVFR late in the period and possibly CMX/IWD after the 18Z TAF period ends. Rain chances are too low to include, but any showers that do occur would not bring vis restrictions. Otherwise east to southeast winds remain elevated around 10-15 kts with gusts safely up to 20-25 kts. That said, there is a 30-50% chance for gusts as high as ~30 kts this evening at IWD as a LLJ passes over. Even if gusts don't overachieve, this likely will result in some LLWS at IWD into tonight.

MARINE

Issued at 207 PM EDT Fri May 22 2026

Winds mainly out of the east are on the increase this afternoon ahead of a couple approaching surface lows, with gusts to 20-25 kts becoming common across the entirety of the lake. Stronger gusts up to 30 kts are possible into the evening hours. Winds settle to 20 kts or less over the west half by Saturday morning, but east half winds remain elevated between 20-30 kts. Winds fall off Saturday night as the low pressures dissipate, likely remaining below 20 kts through much of next week as high pressure returns to the Great Lakes.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ014.

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