textproduct: Marquette

KEY MESSAGES

- A Wind Advisory remains in effect for Northern Houghton and Keweenaw Counties through this evening for strong westerly winds producing wind gusts >45 mph.

- Gale Warnings remain in effect for the Upper Great Lakes through this evening. Westerly gusts 40-45 kts continue with a few Storm force gusts to 50 kts possible (up to 50% chance) near the Keweenaw Peninsula.

- Quieter weather with seasonable to slightly above normal temperatures is expected through much of the work week. The next shot at widespread rainfall returns late Friday through Saturday.

DISCUSSION

Issued at 234 PM EDT Tue Sep 15 2026

Afternoon GOES satellite reveals the dry slot of a deep mid-level in northern Ontario trough draped across the UP and Lake Superior. At the surface, strong pressure rises have been observed in the western lake behind a departing low pressure system. This, and efficient mixing into strong winds aloft, have been able to create sustained winds 25-35 mph in the Keweenaw with 45-55 mph gusts measured at CMX. A Windy Advisory for N Houghton and Keweenaw Counties remains in effect through this evening. Tonight, winds slowly diminish as the pressure gradient slackens with incoming high pressure. Under mostly clear skies and decoupling winds from the boundary layer, some patchy fog is possible across area of the interior. Temps fall into the 40s with low 50s likely near the lakeshores and upper 30s or the interior west and central.

Headed into the rest of the week, seasonable to slightly above normal temperatures will be the rule under mainly zonal flow aloft. Some weak shortwave action may touch off some light rain activity late Wednesday into Thursday. Otherwise, the next best shot at more widespread precipitation returns sometime in the Friday/Saturday timeframe as ascent ramps up ahead of a lifting warm front. At this time, most deterministic models suggest the bulk of the rain remains south across WI and their ensembles counterparts / the NBM point towards potentially meaningful rain (50% chance for >0.5") across the south half of the UP.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 719 PM EDT Tue Sep 15 2026

VFR conditions are expected through the TAF period. High pressure will build into the Upper Great Lakes tonight into Wednesday bringing mainly clear skies and lighter winds. A few hours of gusty winds can be expected at the start of the TAF period but should quickly subside, with light winds thereafter.

MARINE

Issued at 234 PM EDT Tue Sep 15 2026

Lake Superior: Strong pressure rises behind a departing low and increased mixing under cold air advection are contributing to gusty westerlies 35-45 kts across much of the lake, particularly the northern lake around the Keweenaw. Expecting these conditions to persist through the afternoon and early evening before settling down as increasing surface high pressure works to slacken the area pressure gradient. The Gale Warnings in place will ride through 00z tonight (8 PM EDT local). Winds begin to settle below 15 kts tonight and remain so through the majority of the week. Some active weather may bring winds to 25 kts later this weekend.

Northern Green Bay and northwestern Lake Michigan: Breezy SW winds 15-25 kts turn westerly behind a cold front this afternoon while diminishing below 15 kts. Light winds remain through much of the work week. Active weather returning this weekend will likely bring some local increases to the winds above 15 kts at times.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Wind Advisory until 8 PM EDT this evening for MIZ001-003.

Beach Hazards Statement until 10 PM EDT this evening for MIZ006-014.

Lake Superior... Gale Warning until 8 PM EDT /7 PM CDT/ this evening for LSZ241>248-250-251-263>267.

Lake Michigan... None.