textproduct: Marquette

KEY MESSAGES

- Warm this afternoon with southerly breezes. Gales to 35 knots continue over northern Lake Michigan through this evening.

- Cooler/more normal temperatures return for Thursday and Friday.

- Light lake effect rain showers possible over mainly the eastern U.P. for the next few days. Expect little in the way of accumulations.

- Well above normal temperatures expected this weekend.

DISCUSSION

Issued at 308 PM EDT Tue Oct 6 2026

GOES satellite imagery and RAP analysis show a deep, well defined low pressure system crossing into northern Ontario this afternoon, with a trailing surface cold front extending south into Minnesota and very light precipitation associated with the warm front departing the eastern UP. This places Upper Michigan squarely within the warm sector of this system, with temperatures increasing into the low 70s across much of the area this afternoon. Breezy southerly winds are producing gale force gusts over eastern Lake Superior and northern Lake Michigan as unstable boundary layer conditions help winds from a 40 kt low level jet mix down to the surface.

Winds shift west-northwesterly tonight as the cold front sweeps across the UP. This will re-establish a cooler northwest flow, cold air advection regime as upper level troughing sits over the James Bay region through Thursday. Still expect temperatures to make into the 60s across most of the area on Wednesday given relatively modest cold advection, eventually settling back into the 50s on Thursday. Scattered, light lake effect rain showers will redevelop tonight and linger through Thursday, mainly across the east as 850 mb temps cool back below 0 C and lake surface temperatures remain in the 13-15 C range over the eastern half of Lake Superior. Expect very little rainfall out of this activity with amounts generally limited to a few hundredths of an inch over the next few days. The patter will also support breezy west-northwest winds through the end of the work week, frequently gusting to 25-30 mph over the Keweenaw and Lake Superior shoreline and 15-20 mph over the rest of the UP. Dewpoints should mix out nicely each afternoon, introducing some limited fire weather concerns over the next few days as RH values drop into the 30s in interior locations each day.

Warmer weather returns this weekend as the upper level pattern is amplified by a deep trough digging over the western CONUS, placing the Upper Midwest in deep southwest flow and pushing 850 mb temps to 18-20 C over the UP. This should correlate to widespread temps in the 70s both Saturday and Sunday, with some locations in the west and along the WI border currently showing a greater than 50% chance to reach 80 degrees per the NBM. Also expect the forecast to stay dry through the weekend as guidance depicts one system with tropical origins tracking north from the Gulf Coast but staying well to our southeast, while precipitation associated with another low moving out of the northern Rockies stays to the north over Ontario.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 121 PM EDT Tue Oct 6 2026

VFR conditions are expected through the TAF period. Southerly wind gusts up to 20-30kts persist this afternoon. Winds shifting over to the W/NW will diminish this evening at IWD and SAW but remain gusty, to 20kt, at CMX overnight. Wind gusts pick up again at IWD and SAW by Wednesday afternoon.

MARINE

Issued at 308 PM EDT Tue Oct 6 2026

Lake Superior: Southerly gales will drop off quickly in the east through the rest of this afternoon as the low level jet departs and a cold front sweep across the lake from the west this evening. Probabilities for gales remain around 30% for the next few days given relatively modest cold advection and pressure rises, but still expect a prolonged period of 25-30 kt gusts to maintain small craft headlines over the nearshores through Thursday. Expect some lake effect rain showers over mainly the eastern half of the lake Wednesday through Thursday, with some lightning being possible at times given the small amounts of CAPE available in the boundary layer. As sfc high pressure ridging returns to the area Thursday night, expect the winds to slacken to 20 kts or less, staying that way until robust WAA brings southerly winds of 20 to 30 kts back across the lake on Saturday.

Northern Green Bay and northwestern Lake Michigan: Southerly gales continue across the northern nearshores through early this evening, with frequent gusts to 25-30 kt in the bay. Winds weaken to 15 kts or less late tonight as they veer to the northwest behind a cold front. As CAA works down from Canada Wednesday and Thursday, expect northwest winds of 15 to 20 kts to continue until sfc high pressure ridging moving in late this week brings the winds back down to 15 kts or less again by Thursday evening. Expect the light winds to continue through Friday before strong WAA brings southerly winds of 20 to 30 kts back by Saturday.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... None. Lake Michigan... Gale Warning until 8 PM EDT this evening for LMZ248-250.