Marine Weather and Tide Forecast for Big Bay, MI

DISCUSSION
Issued at 311 AM EST Sun Nov 8 2026

Early morning GOES WV imagery shows a sharp trough digging into the CWA from the northwest with a ridge building upstream MT and the Canadian Prairie. Further Upstream a deep trough is landing over the Pacific NW. A 998 mb low over far northern Ontario sends a cold front across the UP today as it continues east. CAA and pressure rises yield windy conditions near Lake Superior with gusts in excess of 35 mph. Widespread gusts across the UP will otherwise be between 20-30 mph. This also kicks up a marginal lake effect rain shower scenario for the east with minimal accumulations of a few hundreths.
Although the forecast currently does not reflect this, wouldn't be surprised if periods of lake enhanced upslope drizzle/sprinkles are able to squeeze out in the Keeweenaw and Michigamme Highlands.
Strong winds across Lake Superior will build dangerous significant wave heights to 10-15 ft over the eastern shores. Otherwise temps generally hold in the 40s today, settling into the 30s to low 40s tonight under cloudy skies.

A small and quick moving shortwave on Monday keeps cloud cover going. CAMs suggest this comes with a brief hitting rain shower over the northern tier, but medium range guidance is not keying in on this moisture. For now added PoPs mostly over Lake Superior, but they do briefly graze the Keweenaw. Temps warm into the 40s to low 50s. A weaker clipper system and associated shortwave travel to the north of Lake Superior Monday night into Tuesday, all precip remains to the north. A deeper trough following into Wednesday brings another clipper with it, but what primarily introduces precip back into the forecast is the colder airmass that accompanies it. 850 mb temps drop to -8 C end of Wednesday, continuing through at least Friday, possibly through much of Saturday (20% chance). This keeps lake effect showers, mainly snow, through early next weekend out of the north. Model soundings don't indicate much of any presence within the DGZ during this period or impressive moisture, but some light snow accumulation is anticipated by the end of the week.
Probabilities for 1 inch of snow by 12Z Saturday are 40-70% over the north wind snowbelts. Increase the total to 4 inches and it drops to 20% at most. Otherwise temps return near normal with highs in the 30s to low 40s and lows in the 20s to low 30s.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/
Issued at 629 AM EST Sun Nov 8 2026

VFR conditions this morning will give way to MVFR as lake effect clouds develop and move onshore mid to late morning. This will bring MVFR through the remainder of the TAF period. West-northwest winds will become gusty, as high as 30-35 kt at CMX and 25 kt at IWD and SAW. A period of LLWS can be expected at SAW this morning, thereafter stronger surface wind and mixing will end the LLWS.

MARINE
Issued at 311 AM EST Sun Nov 8 2026

Lake Superior: A clipper tracking to the north today sends a cold front across the lake this morning with northwest winds of 20-30 kts expected by this afternoon in its wake. Gusts up to 30 kts in the west with gales of 35-45 kts in the east are expected. Strongest gusts will be in the southern waters between Big Bay, Stannard Rock and Grand Marais where there is a low chance (10-25%) for storm force gusts. Maintained Gale headlines as is. Significant wave heights of 4-8 ft in the west this morning gradually decrease this afternoon with the west wind shift and eventual tapering winds, falling below 4 ft this evening. Waves in the east peak late this afternoon between 8-15 ft, highest Munising eastward. High pressure ridging returning tonight tapers winds off from west to east, with winds falling below 20 kts by Monday morning. Waves gradually fall below 4 ft in the east half Monday morning.

Another clipper system tracks north of the lake Monday night into Tuesday, however this system is weaker and gale potential remains low (10-30% chance). High pressure keeps winds seasonally benign the rest of the forecast.

Northern Lake Michigan and northern Bay of Green Bay: Southwest winds of 15-20 kts this morning become northwest by this afternoon in the wake of a cold front with gusts around 25 kts. Winds fall below 20 kts early tonight, remaining near or below 20 kts through the remainder of the forecast.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
None.
Lake Superior...
Gale Warning until 7 PM EST this evening for LSZ244>247.

Gale Warning until 10 PM EST this evening for LSZ248-265.

Gale Warning until 10 PM EST this evening for LSZ249-250-266.

Gale Warning from 10 AM this morning to 10 PM EST this evening for LSZ251-267.

Lake Michigan...
None.