textproduct: Marquette

KEY MESSAGES

- Widespread showers and thunderstorms arrives over the west half today, spreading east overnight and Wednesday before ending for most late Wednesday.

- Expect dangerous waves and rip currents over the Lake Michigan beaches of Schoolcraft County on Wednesday.

- Generally seasonable temperatures are expected through the rest of this week.

DISCUSSION

Issued at 239 AM EDT Tue Aug 25 2026

High level clouds from the approaching Clipper low continue to move into the U.P. early this morning, with showers and storms potentially moving into the Ironwood area by the late morning hours as the Clipper's warm front starts to arrive. While the GFS shows modest isentropic lift along the warm front and PWATs increasing to 1.25 to 1.50 inches, given the limited amount of instability within the atmosphere (only 1 kJ/kg or less) and sub-optimal 0-6 km shear (~30 knots), thinking that while a strong storm or two could be seen over the far west (generally late this afternoon to early this evening), no storms should technically reach severe weather criteria (i.e. tornadoes, hail of 1 inch or greater, 60+ mph winds). That being said, wouldn't be surprised if we had some storms pop-up and bring some stronger winds up to 50 mph and small hail up to a dime or nickel in size down to the sfc. In addition to these hazards, heavy rainfall could be seen in the stronger showers and storms, with some spots potentially receiving over an inch of rainfall, even in the convection that occurs tonight through Wednesday as the cold front followed by the wrap-around moisture behind the Clipper moves over the rest of Upper MI. While there is still some uncertainty on the exact timing of the warm front, cold front, and wrap-around moisture of the low, and whether the front's occlude or not, there is high confidence (60-90%) that rainfall will be seen across the area between now and Thursday morning. However, given the convective nature of the rainfall, some spots could receive a 'feast' of rainfall while others see a 'famine'; the latest NBM probabilities show a general 10-60% chance for receiving more than an inch of rainfall between this morning and Thursday morning, with the highest chances being seen in the east; that being said, the latest NBM also shows up to around a 20% chance for less than a tenth of an inch in the areas near the WI border, particularly in the south central, for the same time period. Expect the rainfall over the U.P. to wrap up Wednesday night as the (probably) lake-enhanced rain showers dwindle down across the area. In addition to the rainfall, the Clipper is expected to bring strong southerly winds to the Great Lakes. This in turn is projected to create dangerous rip currents and high waves along the beaches of Schoolcraft County on Wednesday. Therefore, while one has not been issued yet, expect a Beach Hazard Statement to be forthcoming this afternoon for Schoolcraft County on Wednesday.

Expect fairly normal temperatures this week into next week across the area as dry weather returns via incoming high pressure ridging once again late this week. While it looks like we may get a day or two of reprieve from rainfall, medium range guidance does suggest that additional shortwaves enter the Upper Midwest sometime this weekend through early next week as ridging deamplifies over the Central CONUS and troughing develops over the western U.S.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 110 AM EDT Tue Aug 25 2026

An approaching low pressure and cold front will bring the chance for showers and thunderstorms to the western half of the UP Tuesday afternoon, spreading east through the early evening. Multiple waves of showers and thunderstorms are expected but the timing and location of each wave is difficult to pin down. Handled most of the shower and thunderstorm activity with PROB30s due the the uncertainty. Expect MVFR and IFR conditions in the heavier showers and thunderstorms. Have also removed the mention of fog at SAW for tonight; high level cloudiness looks like it will help limit radiation cooling and the threat for fog.

Overall winds will be light and variable the rest of tonight, becoming southerly 5-10 kt on Tuesday.

MARINE

Issued at 239 AM EDT Tue Aug 25 2026

Generally light winds of 15 kts or less continue until this afternoon, when increasing winds from the south build to 20 to 25 kts by the evening hours over northwestern Lake MI, northern Green Bay, and eastern Lake Superior as the warm front of an incoming Clipper low moves through the area. With the arrival of the warm front today, expect showers and thunderstorms to move over western Lake Superior today, eventually moving into the rest of the western Great Lakes tonight into Wednesday; some severe, erratic winds up to 40 kts and marginally severe hail (up to around a dime in diameter) could be seen over western Lake Superiors this afternoon and early evening. Therefore, boaters over the western lake should keep their Weather Radios nearby and remain weather-aware. Gusty winds of 20 to 25 kts veer towards the southwest tonight, eventually becoming west to northwest 20 to 25 kts over Lake Superior on Wednesday. While CAA behind the Clipper looks to increase northwest winds to 20 to 30 kts over the eastern half of Lake Superior Wednesday night, expect the winds over the lake to drop to 20 kts or less by Thursday afternoon as northwest winds of 15 to 20 kts continue over northern Green Bay and northwest Lake MI Wednesday night until Thursday evening. Light winds of 15 kts or less continue over the Upper Great Lakes on Friday as high pressure ridging pushes through the region. However, as troughing develops over the western U.S. and high pressure ridging weakens over the central CONUS, expect showers and storms to potentially return this weekend, with southerly winds of 20 to 25 kts returning to northern Green Bay, northwest Lake MI, and eastern Lake Superior by Saturday evening.

MQT WATCHES/WARNINGS/ADVISORIES

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