Great Lakes Forecast
Issued by NWS
Issued by NWS
844 FZUS63 KMQT 311401 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1001 AM EDT Mon Aug 31 2026 For waters beyond 5 nautical miles of shore on Lake Superior. Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS... A 29.4 inch low over Southern Saskatchewan will weaken to 29.6 inches as it moves to east-central Manitoba late tonight. This will bring a weak, broad 29.9 inch trough over the Upper Great Lakes. Weak troughing remains over the lake until ridging of around 29.9 inches builds over the lake on Wednesday and strengthens to 30.1 inches through Friday. Ridging will continue to build to 30.2 inches by Sunday morning as a high pressure center over eastern Canada moves southward over the weekend. LSZ162-312000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1001 AM EDT Mon Aug 31 2026 /901 AM CDT Mon Aug 31 2026/ .REST OF TODAY...East winds 5 to 15 knots backing northeast in the afternoon, then backing west late. Waves calm to 2 feet. .TONIGHT...West winds 5 to 15 knots backing southwest after midnight. Waves calm to 2 feet. .TUESDAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots in the afternoon, then veering west late. Waves building to 1 to 3 feet. .TUESDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots backing south by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY...Northeast winds 15 to 25 knots diminishing to 10 to 20 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .FRIDAY...Northeast winds 15 to 25 knots diminishing to 10 to 20 knots. Waves calm to 2 feet. $$ LSZ263-312000- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1001 AM EDT Mon Aug 31 2026 .REST OF TODAY...Southeast winds 10 to 20 knots becoming east 5 to 15 knots in the afternoon, then veering west late. Patchy fog. A chance of showers and a slight chance of thunderstorms. Waves 1 to 3 feet. .TONIGHT...West winds 5 to 15 knots backing southwest after midnight. Patchy fog. Waves subsiding to calm to 2 feet. .TUESDAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots in the afternoon, then veering west late. Waves building to 2 to 4 feet. .TUESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots backing southwest by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...East winds less than 10 knots. Waves calm to 2 feet. .THURSDAY...East winds 10 to 20 knots. Waves calm to 2 feet. .FRIDAY...East winds 10 to 20 knots. Waves calm to 2 feet. $$ LSZ264-312000- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1001 AM EDT Mon Aug 31 2026 .REST OF TODAY...Southeast winds 10 to 20 knots diminishing to 5 to 15 knots late. Patchy fog. A chance of showers. A slight chance of thunderstorms by mid afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TONIGHT...West winds 5 to 15 knots backing southwest late. Patchy fog. Waves subsiding to calm to 2 feet. .TUESDAY...Southwest winds 5 to 15 knots increasing to 15 to 25 knots. Patchy fog through early afternoon. Waves building to 1 to 3 feet. .TUESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .WEDNESDAY...Northwest winds 5 to 15 knots becoming west less than 10 knots by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...West winds less than 10 knots veering north after midnight. Waves calm to 2 feet. .THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet. .FRIDAY...East winds 10 to 20 knots. Waves calm to 2 feet. $$ LSZ265-312000- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1001 AM EDT Mon Aug 31 2026 .REST OF TODAY...Southeast winds 15 to 25 knots diminishing to 10 to 20 knots in the afternoon, then backing east late. Patchy fog by late morning. A slight chance of showers and thunderstorms by mid afternoon. Waves 1 to 3 feet subsiding to calm to 2 feet. .TONIGHT...West winds 10 to 20 knots backing southwest late. Patchy fog. Waves calm to 2 feet. .TUESDAY...South winds 10 to 20 knots veering west late. Patchy fog through early afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots veering north by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY...East winds 5 to 15 knots veering southeast. Waves calm to 2 feet. .FRIDAY...East winds 10 to 20 knots veering southeast. Waves calm to 2 feet. $$ LSZ266-312000- Lake Superior East of a line from Manitou Island to Marquette MI and West of a line from Grand Marais MI to the US/Canadian Border Beyond 5NM from shore- 1001 AM EDT Mon Aug 31 2026 .REST OF TODAY...Southeast winds 10 to 20 knots. Patchy fog. A chance of showers and a slight chance of thunderstorms. Waves 1 to 3 feet building to 2 to 4 feet, then subsiding to 1 to 3 feet. .TONIGHT...Southeast winds 10 to 20 knots veering west after midnight, then diminishing to 5 to 15 knots late. A slight chance of showers and thunderstorms through midnight. Patchy fog through midnight, then areas of dense fog after midnight. Waves subsiding to calm to 2 feet. .TUESDAY...South winds 5 to 15 knots increasing to 10 to 20 knots in the afternoon, then veering southwest late. Patchy dense fog through early afternoon. Waves building to 1 to 3 feet. .TUESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots veering northwest by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY...North winds 5 to 15 knots veering east. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots veering southeast. Waves calm to 2 feet. $$ LSZ267-312000- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 1001 AM EDT Mon Aug 31 2026 .REST OF TODAY...Southeast winds 15 to 25 knots diminishing to 10 to 20 knots late. Patchy fog. A chance of showers and a slight chance of thunderstorms. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TONIGHT...Southeast winds 10 to 20 knots veering west after midnight, then diminishing to 5 to 15 knots late. A slight chance of showers and thunderstorms through midnight. Patchy fog through midnight, then areas of dense fog after midnight. Waves subsiding to calm to 2 feet. .TUESDAY...Southwest winds 5 to 15 knots backing south in the afternoon, then increasing to 10 to 20 knots late. Widespread dense fog through early afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...West winds 10 to 20 knots. A slight chance of showers through midnight. Waves calm to 2 feet. .WEDNESDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY...Northwest winds 5 to 15 knots veering north. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots. Waves calm to 2 feet. $$ LSZ261-312000- MAFOR 3115/ Superior West 11300 11700 12610 11600 12500 11510. Waves 2 feet or less. Superior North Central 11320 11310 11300 11500 11604 11600 12510. A chance of showers this afternoon. Waves 2 to 4 feet this afternoon. Waves 1 to 3 feet tonight and Tuesday morning. Superior South Central 12320 11310 13610 11510 11410. Waves 1 to 3 feet. Superior East 12320 12310 11514 12604 11504. A chance of showers this afternoon. Waves 2 to 4 feet this afternoon. Waves 1 to 3 feet tonight and Tuesday morning. $$ WFO MQT Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes