textproduct: Marquette

KEY MESSAGES

- Isolated light rain showers into tonight. Patchy dense possible fog near Wisconsin tonight into Saturday morning (20-40% chance).

- Above-average temperatures persist through Labor Day Weekend, with high temperatures in the mid 70s to low 80s.

- Dry conditions prevail Saturday and Sunday. Precipitation chances increase late on Labor Day, reaching 50% in the west by the evening.

DISCUSSION

Issued at 328 PM EDT Fri Sep 4 2026

Afternoon GOES WV imagery shows the upper level ridge over the Plains with an upstream closed low spinning over the Pacific Northwest, a downstream trough over Quebec, and an elongated shortwave just north of Lake Superior. At the sfc, high pressure over Hudson Bay is extending ridging south over Ontario and into the CWA. Despite the overcast skies, SPC mesoanalysis indicates MUCAPE between 500-1000 J/kg over the west supported by Tds in the mid 60s. Temps are not expected to climb much further today, peaking in the upper 60s to mid 70s. Isolated showers continue into tonight, gradually diminishing as instability aloft falls and high pressure builds in from the north. Mostly negligible rainfall amounts, but isolated totals of a few hundreths is forecast. Fog development is expected in the west tonight courtesy of ample low level moisture and light winds. Particularly focused on fog near the WI/MI state line where patchy dense fog down to 1/4 mile is possible (20-40% chance) into early Saturday morning. Otherwise lows will be in the mid 50s to low 60s.

With high pressure and upper level ridging dominating the remainder of Labor Day weekend, dry weather is expected. Temperatures remain 5 to 10 degrees above normal with highs in the 70s to low 80s and lows mainly in the 50s to low 60s. Saturday night is an exception with near normal lows in the mid 40s to mid 50s as drier air, light winds and mostly clear skies under high pressure influence support radiative cooling processes.

Precip chances return Monday night from the west, continuing into Tuesday night as the upper level ridge moves east and flattens. This gives way to the deep western trough to lift northeast to Manitoba by the end of the day Tuesday, then tracking east to Quebec. A resulting sfc low from the northern Rockies lifts to Manitoba by Tuesday morning, then moves across far northern Ontario to Quebec through Wednesday. Showers and storms return to the UP ahead of the associated cold front, mainly on Tuesday. This does not look to bring much in the way of strong storms, but it does present the best rainfall chances as of recent. NBM probabilities of at least 1 inch of rain in 24 hours are between 30-50%. This system also yields breezy winds. Initially expecting south winds on Tuesday ahead of the cold front gusting between 15-30 mph, particulary in ideal southerly downslope flow. Behind the front, pressure rises and CAA support stronger westerly winds on Wednesday with frequent gusts of 20-30 mph. Probabilities for wind gusts exceeding 40 mph are between 30-60% in the Keweenaw.

There is a slight chance (15-24% chance) for additional showers late Wednesday into Thursday with a shortwave to the north and a secondary cold front pressing south. Otherwise temps return near normal in the mid 60s to mid 70s late next week.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 151 PM EDT Fri Sep 4 2026

Lingering moisture underneath a building ridge aloft is creating MVFR to IFR cigs at all sites this afternoon. These conditions are expected to remain the same through evening. A few spotty showers may be seen in the west half of the UP, so opted to include prob30s for -shra this evening. Otherwise, with decreasing winds tonight and low level moisture in place, fog development is likely to occur. HREF probs for vis <1 sm is lower than anticipated (only ~30% at IWD), however, given the favorable conditions for overnight and morning fog, have included a tempo group for 1 SM vis at IWD for now. Future TAF updates may include FG at CMX/SAW as confidence increases or area observations reveal fog development.

MARINE

Issued at 354 PM EDT Fri Sep 4 2026

Lake Superior: Lingering northeast wind gusts above 20 kts in the western waters falls below 20 kts this evening with high pressure building in from the north. This high pressure influence keeps winds below 20 kts through early Monday afternoon. A more prominent system lifting to the north of Lake Superior Monday night through mid week brings a prolonged period of 20 to 30 kt winds. Best chances for gales to 35 kts (30 to 60% chance) are Wednesday behind the cold front, supported by pressure rises. There is a low (15 to 25%) chance for southerly warm air advection gales on Tuesday and a 20 to 40% chance for high end gales (40 kts or higher) near the Keweenaw on Wednesday. Winds settle below 20 kts by late next week.

Northern Green Bay and northwestern Lake Michigan: Winds generally remain 15 kts or lower through Labor Day as high pressure slowly builds overhead. A more prominent system lifting north of the region early next week increases winds to around 15 kts with gusts up to 20 to 30 kts Tuesday afternoon through Wednesday.

MQT WATCHES/WARNINGS/ADVISORIES

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