textproduct: Marquette

KEY MESSAGES

- Heavier rain and thunderstorms are possible late tonight into Monday morning. Severe weather is not expected.

- A second round of showers and thunderstorms is possible Monday afternoon. There is a marginal risk (~%5 chance) of severe thunderstorms over the southcentral UP Monday afternoon.

- Drier weather with above normal temperatures and higher humidity is expected for much of the rest of the week.

DISCUSSION

Issued at 352 PM EDT Sun Aug 30 2026

Visible satellite shows abundant cloud cover over the UP this afternoon, helping to hold temperatures down in the upper 60s to low 70s across the area today as a mid level disturbance passes well south across southern Wisconsin and Lower Michigan. A band of light rain showers can be seen tracking east across the area on radar imagery, but this has produced no more than few hundredths of an inch of precipitation at any location thus far today and will remain light as it continues eastward this evening. Chances for more meaningful rainfall increase tonight as a warm front lifts into the area ahead of a surface low moving out of the Dakotas into the Upper Mississippi River Valley, with PWATS surging above 1.75" or close to the max of nearby sounding climatology. Latest HREF guidance depicts a 50-80% chance to receive a wetting rain of at least a quarter inch across the western and southcentral UP through tonight through Monday afternoon, with closer to a 30-40% chance from Marquette into the eastern UP. Could also see a few rumbles of thunder overnight with this activity, but timing will help to limit any severe potential as CAPE will only be on the order of a few hundred J/kg.

Highs will climb into the 80s on Monday afternoon as mid level warm advection sends 850 mb tamps towards 20C. Some of the CAMS continue to depict a second round of showers and thunderstorms developing Monday afternoon as another disturbance moves in behind the departing warm front. This convection would potentially have more to work with as the warm and moist environment yields increasing instability and bulk shear values increase to around 40 kt Monday afternoon. One caveat is how much clearing will occur behind the initial round of convection tonight into Monday, which could hinder how much destabilization is ultimately realized. Regardless, SPC has pulled its Day 2 marginal severe risk northward into the southcentral UP for Monday afternoon.

The forecast trends drier on Tuesday as Upper Michigan becomes situated between low pressure over northern Ontario and high pressure over the Tennessee Valley, which another day of highs in the 80s expected. The ridge then reamplifies over the central CONUS for the latter half of the week as the low over Ontario moves east to the Canadian Maritimes, placing the UP back into a northwest flow regime with temperature moderating into the 70s into next weekend. This will favor generally drier weather through the end of the week, though a few periods of showers can't be ruled out with any embedded disturbances passing through the region.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 725 PM EDT Sun Aug 30 2026

Flight restrictions will continue at all TAF sites through the TAF period due to low level cloud cover and fog formation. Currently, MVFR restrictions persist at IWD while CMX and SAW continue to show IFR/LIFR ceilings. All TAF sites will quickly deteriorate to IFR/LIFR again by tonight, though, as a warm front brings additional shower and thunderstorm chances. The rain could help to alleviate the fog threat briefly, but LIFR cigs are expected regardless. And, fog will likely form in the wake of the rainfall. Gradual improvement to MVFR is expected mid to late morning tomorrow, but a return to VFR may not happen until late tomorrow afternoon. Meanwhile, expect the winds to build from the E/SE later today as the warm front approaches. The sustained winds lighten up a little but continue as they slowly veer throughout the overnight hours.

MARINE

Issued at 352 PM EDT Sun Aug 30 2026

Lake Superior: NE winds increase to 15-25 kt over the western lake this evening as a warm front approaches, with a few small craft headlines in place for western Lake Superior nearshores through 8 PM EDT. As the showers and storms associated with the front start to move in tonight from the SW, expect the winds to dwindle over the western lake while increasing from the SE to 20 to 25 kts over the eastern half of the lake on Monday. Expect light winds of 20 kts or less to return to Lake Superior Monday night. However, SW winds of 20 to 25 kts could return between Isle Royale and the Keweenaw on Tuesday before becoming 20 kts or less again Tuesday evening. The light winds remain until potentially late on Thursday when NE winds of 20 to 25 kts possibly return to the western arm.

Northern Green Bay and northwestern Lake Michigan: Light winds of 15 kts or less look to continue until Monday. Meanwhile, some showers and storms could be seen through tonight, with some potentially marginally marine severe weather possible tonight (gusty winds up to 34 kts and hail up to dime sized). We could see some S'rly winds of 15 to 20 kts over the area on Monday before winds return to 15 kts or less Monday evening. The light winds continue through the rest of the week, although some more showers and storms could return on Wednesday.

MQT WATCHES/WARNINGS/ADVISORIES

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