textproduct: Marquette

KEY MESSAGES

- Spotty showers and storms continue across the central and eastern UP this afternoon. Light rainfall totals mainly less than a tenth of an inch are expected, with higher totals possible where heavier downpours or multiple rounds of storms occur.

- Seasonable temperatures are expected through next week with the exception of slightly below normal temperatures Sunday and Sunday night.

DISCUSSION

Issued at 230 PM EDT Sat Aug 22 2026

Afternoon water vapor imagery reveals quite nicely the midlevel trough dropping into the Great Lakes, with a surface low centered over Lake Huron. Steepening lapse rates courtesy of the resulting CAA into the region is aiding in the development of scattered convection over the central UP, with some additional spotty showers in the eastern UP. Day Cloud RGB shows plenty of glaciation over the south-central UP, and indeed some stray flashes have been observed already. That said, with little by way of shear, storms are coming up just enough to get a couple strikes, then falling back down again. With freezing levels at around 10kft and a -20C at around 20kft, an ambitious taller cell could perhaps make a run for some small hail. Otherwise, strong storms are not expected.

Meanwhile, with a tight pressure gradient over the region as ridging expands eastward from the Northern Plains as well as decent mixing into the core of 20-30kt winds aloft, winds are turning becoming elevated this afternoon. NW wind gusts up to 20mph are becoming common, but higher gusts to 30mph will not be out of the question by late afternoon in the eastern UP. Temperatures peak cooler than in previous days, only in the upper 60s to lower 70s for most and possibly the mid 70s in the south-central. Precipitation tapers off this evening, followed by mostly clear skies overnight. Temperatures bottom out in the lower to mid 40s inland, and the lower 50s near the lakeshores. Still, with note a potential for some of our typically cooler spots to slip into the upper 30s, a la the NBM 10th percentile. By Sunday morning, much of the hi-res guidance favors some spotty shower activity over the north-central UP, perhaps due to cool upsloping flow. Breezy conditions continue for Sunday with NW wind gusts up to 20-30mph, while temperatures come in a couple degrees cooler; expect highs in the mid to upper 60s for most. Some interior spots likely will dip back into the upper 30s Sunday night under clear skies.

High pressure moving in from the west keeps weather dry through Monday, likely through most of Tuesday as well before the next mid level trough moves through the region midweek. This brings back shower and storm chances for Tuesday night and Wednesday, then dry weather is favored the rest of the work week. Expect more summer- like temperatures to return this week, with highs ranging in the 70s to near 80 Monday onwards and lows generally in the 50s.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 723 PM EDT Sat Aug 22 2026

VFR conditions are expected through the TAF period for CMX and IWD. As temperatures drop aloft lake effect clouds and showers will develop over Lake Superior on Sunday, potentially impacting SAW during the morning into the early afternoon. CIGs at SAW will be borderline VFR/MVFR during this time and likely fall to MVFR in any showers that impact the site. Confidence is still low on coverage and timing so kept the mention to a prob30. As mixing increases through the day expect winds to gust as high as 25kt at CMX/SAW from mid morning Sunday through the afternoon.

MARINE

Issued at 230 PM EDT Sat Aug 22 2026

Lake Superior - NW winds are on the increase this afternoon, already gusting to around 20-25kts over the eastern half of the lake so far. Higher gusts up to 25-30kts become more common into the late afternoon. Gusts approach 20 kts over the west. As winds become more northerly tonight, central lake superior winds increase to 15-25 kts; the stronger winds to 30 kts over the east persist. This holds into Sunday morning before winds gradually simmer down from west to east into Sunday night. This builds significant waves of 3-7 ft over the southeastern waters this weekend. Probabilities for gales to 35 kts are only between 15-30%, highest south of Stannard Rock and along the Marquette/Alger County shores Sunday afternoon. Wind gusts to 20kts linger over the eastern half of the lake Monday, then winds stay below 20kts Tuesday before the next system brings back winds up to 20-25 kts Tuesday night into Wednesday morning.

Northern Bay of Green Bay and northern Lake Michigan - NW wind gusts to 20-25kts become common this afternoon, persisting through Sunday. Winds fall back below 20 kts Sunday night, remaining below 20 kts through much of next week. Scattered showers and storms continue the rest of this afternoon, tapering off this evening. Dry weather then persists until midweek next week.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ005-006.

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