textproduct: Marquette

KEY MESSAGES

- Light rain continues this afternoon and evening, mainly closer to the stateline.

- Patchy dense fog is possible (50-75% chance) across the interior UP overnight through early Sunday morning.

- Additional showers and storms are possible through early next week.

- Above normal temperatures and higher humidity is expected this weekend into early next week, likely continuing into early September.

DISCUSSION

Issued at 143 PM EDT Sat Aug 29 2026

Afternoon GOES satellite imagery reveals a few shortwave ripples in zonal flow aloft forcing mid-level isentropic ascent. So far the best ascent has been focused across north and central WI with only scattered showers lifting into the western half of the UP. Given the current trajectory of precip on radar and model precip struggling to lift much rain into the northern tier of the UP, thinking the bulk of rainfall will be found in the southern half. CAM ensembles are still meh about healthy widespread rain, only showing a 10-30% chance for amounts greater than a quarter inch anywhere north of Menominee County. As showers skirt east tonight, increased surface moisture (dewpoints in the 60s) combined with light winds and area rainfall will help patchy dense fog develop through day break. Areas of dense fog will be more common across the interior, especially areas that saw more rainfall.

Weak height rises on Sunday should hold dry conditions for the UP tomorrow though cannot rule out some spotty precip redeveloping across the south half (10-30% chance). The next best shot at more meaningful rainfall returns Monday with a warm front lifting into the Great Lakes. Surging moisture brings PWATs between 1.5-2" (~99th percentile of NAEFS climo for this time of year up here) and MUCAPE values >1500 j/kg. Should bulk shear 35-45 kts be present, a marginal severe weather threat may shape up as convection lifts ahead of this boundary. Ensembles aren't sold on heavy rain quite yet (25-50% chance for amounts >0.25"), but I suspect CAMs will pick up on a heavy rain threat once we get closer to the event. The tail end of the incoming 12z HREF shows pockets of 1-1.5" of rain per 6hr LPMM. This is a welcomed sight as drought concerns grow headed into the typical "second fire season" up here.

Some additional rain showers and thunderstorms could be seen behind the warm front Monday evening into Tuesday. However, rain chances diminish from the mid-week until near the end of the forecast period as high pressure ridging rebuilds over the central CONUS. Thus, rain chances will be relegated to mesoscale forcing mechanisms (for example, the lake breeze) due to the lack of synoptic-scale forcing. Because warm air from the Gulf is continuing to be pumped over the region behind the warm front, expect the above normal temperatures and humid conditions seen this weekend through early next week to continue through the rest of next week.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 713 PM EDT Sat Aug 29 2026

VFR conditions to start will deteriorate to MVFR/IFR tonight as fog and low stratus develop following today's showers. All of the terminals are showing at least a 50% chance for MVFR or lower cigs and/or vis, with the best chances for IFR at SAW. As for the winds, expect winds to turn light and variable tonight.

MARINE

Issued at 143 PM EDT Sat Aug 29 2026

Lake Superior: A weak shortwave lifts light rain showers into the area this afternoon and evening. Winds to remain light at 20 kts or less. Areas of marine fog are possible as moisture pools into the Great Lakes region. Another shortwave moves into the Upper Midwest on Sunday and looks to bring NE to E winds of 20 to 30 kts over the western half of the lake by the afternoon hours. As the winds veer more E over the far west, expect them to decrease with time before increasing back up to 20 to 30 kts from the SE over the eastern half of the lake on Monday ahead of an incoming warm front. Some additional showers and storms could be seen with the warm front's passage, with some severe weather being possible in the worst storms. The winds die down to 20 kts or less behind the warm front, although they may gust up to 20 to 25 kts from the SW on Tuesday over the western half of the lake (mainly between Isle Royale and the Keweenaw). As high pressure ridging builds back over the central CONUS by the middle of the week, expect the winds to remain light at around 20 kts or less for the rest of the week.

Northern Green Bay and northwestern Lake Michigan: Light rain and light winds expected for the remainder of Saturday. Areas of dense fog are possible tonight into early Sunday with increased moisture and decreasing winds. Additional showers could be seen on Sunday as well as a second shortwave moves through the Upper Midwest, but chances are currently forecasted to be lower than what they are for today (only a 20 to 40% chance for Sunday). As a warm front moves into the area on Monday, winds look to build to 15 to 20 kts from the SE as showers and storms potentially move through; some severe weather is possible in the worst storms. Winds die down to 15 kts or less again behind the warm front on Monday evening, even as showers and storms continue through potentially Tuesday. As high pressure builds back over the central CONUS, expect generally calmer weather and light winds of 15 kts or less through the rest of the week.

MQT WATCHES/WARNINGS/ADVISORIES

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