textproduct: Marquette

KEY MESSAGES

- Fog in the central and east tonight into Sunday morning could be dense at times, reducing visibility down to 1/4 mile (30% chance).

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

- A low pressure system tracking to the north early next week brings rain chances on Tuesday and breezy winds Tuesday and Wednesday.

- Frequent westerly wind gusts of 20 to 30 mph are expected on Wednesday. There is a 25-50% chance for gusts up to 40 mph near Lake Superior and 50-70% chance for gusts up to 45 mph in the Keweenaw. West gales of 35+ knots are becoming increasingly likely for Lake Superior.

DISCUSSION

Issued at 356 PM EDT Sat Sep 5 2026

Afternoon GOES WV imagery places the upper level ridge axis over the Plains with two elongated closed lows on either side of the ridge over the Pacific Northwest and the Gulf of St Lawrence. At the sfc, RAP analysis has high pressure over eastern Canada, sending ridging into the Great Lakes. Not much is expected to change with this pattern through Sunday with an overall warm and pleasant Labor Day weekend expected. With the high pressure ridge building gradually overhead and sfc troughing over the Northern Plains, the pressure gradient remains weak with light northeast to east flow. As a result, dry weather persists through Monday and Lake Breezes are expected today and Sunday. Highs this afternoon through Monday peak in the 70s with interior locations observing low 80s Sunday and Monday. With little cloud cover and calm conditions tonight, radiative cooling brings temps down into the 40s away from the lakeshores with upper 40s to mid 50s at the shores. Fog development is expected again tonight; patchy dense fog down to 1/4 mile is possible in the central and eastern UP into Sunday morning (~30% chance). As the ridge shifts east and troughing deepens over the Plains, southerly flow increases cloud cover on Monday and continues the warming trend for overnight lows. Temps settle into the mid 50s to mid 60s Monday night and upper 50s to 60s Tuesday night.

Precip chances return Monday night from the west, continuing into Tuesday night as the upper level ridge moves east over the Great Lakes and flattens. This gives way to the deep western trough to lift northeast to Manitoba by Tuesday afternoon, which then tracks east to Quebec through Wednesday. A resulting sfc low from the northern Rockies lifts to Manitoba for Tuesday, then moves across far northern Ontario to Quebec through Wednesday. Showers return to the UP ahead of the associated cold front, mainly on Tuesday. Instability struggling to reach 500 j/kg mean strong to severe storms are not expected. Widespread rainfall amounts have trended down as deterministic solutions are indicating QPF splits somewhat around the UP. Probabilities of at least 1 inch of rain in 24 hours are now 30-60% only over the north half and far western Upper Peninsula, quickly falling to 10-25% elsewhere. 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 gusts exceeding 40 mph are between 25-50% from Marquette to Whitefish point and Saxon Harbor to Ontonagon. Could see a Wind Advisory being needed in the Keweenaw where probabilities for gusts exceeding 45 mph already are between 50-70%.

Weak high pressure ridging returning to the area bring back much calmer conditions on Thursday. The drying trend in the forecast has also removed lingering precip chances until the weekend, although the marginally cold enough 850 mb temps could yield scattered lake effect cloud cover late Wednesday night into Thursday. Otherwise temps return near normal in the upper 60s to mid 70s late next week.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 145 PM EDT Sat Sep 5 2026

VFR conditions and light winds prevail through much of the TAF period under high pressure. Another round of early morning radiation fog will be the primary aviation hazard at SAW and potentially CMX before lifting just after sunrise. Confidence is lower regarding fog development at CMX, but given light easterly upsloping there chance is low but non-zero.

MARINE

Issued at 356 PM EDT Sat Sep 5 2026

Lake Superior: 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 Wednesday brings a prolonged period of widespread 20 to 30 kt winds. Best chances for gales to 35 kts (40 to 80% chance, highest near the Keweenaw) are Wednesday behind the cold front, supported by pressure rises. There is a low (20 to 40%) chance for southerly warm air advection gales on Tuesday and a 20 to 50% chance for high end gales (40 kts or higher) near the Keweenaw on Wednesday. Winds settle below 20 kts by Thursday afternoon. Another system traveling north of Lake Superior brings stronger wind potential into early next weekend, but significant model discrepancies leave confidence low.

Northern Green Bay and northwestern Lake Michigan: Winds 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. Winds settle below 20 kts b Thursday morning, holding below 20 kts into Friday. Another system traveling north of Lake Superior brings stronger wind potential into early next weekend, but significant model discrepancies leave confidence low.

MQT WATCHES/WARNINGS/ADVISORIES

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