FZUS63 KMQT 231401 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1000 AM EDT Sun Aug 23 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... This morning, a 29.7 inch low is along the Quebec/Ontario line while 30.1 inch high pressure extends from northwestern Ontario to Iowa. Little movement is expected with only a slight weakening of both pressure centers through today and tonight. By Monday night, the low weakens to 29.8 inches as it fully moves into Quebec, allowing the high to also weaken to 30.0 inches and settle over the Upper Great Lakes. Meanwhile, 29.8 inch low pressure moves over Lake Winnipeg. These systems all shift east slowly through Wednesday afternoon, when the weak high moves over New England as the 29.7 inch low moves over Lake Superior. By Thursday afternoon, the low will deepen to 29.6 inches over western Quebec as a 30.2 inch high moves over northern Manitoba. This high will extend 30.1 inch ridging over Lake Superior Friday into the weekend. LSZ162-232000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1000 AM EDT Sun Aug 23 2026 /900 AM CDT Sun Aug 23 2026/ .REST OF TODAY...North winds 5 to 15 knots backing southwest in the afternoon. Waves calm to 2 feet. .TONIGHT...Southwest winds 5 to 15 knots veering northwest after midnight, then veering north late. Waves calm to 2 feet. .MONDAY...North winds 5 to 15 knots veering south in the afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southeast winds 5 to 15 knots becoming south less than 10 knots after midnight. A slight chance of showers after midnight. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots backing east by mid afternoon. A chance of showers through early afternoon, then showers likely and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 5 to 15 knots veering west after midnight. Showers likely through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots becoming northwest 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots becoming north 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-232000- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1000 AM EDT Sun Aug 23 2026 .REST OF TODAY...North winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon, then backing west late. Waves 1 to 3 feet subsiding to calm to 2 feet. .TONIGHT...West winds 5 to 15 knots veering north late. Waves calm to 2 feet. .MONDAY...North winds 5 to 15 knots backing northwest in the afternoon, then backing southwest late. Waves calm to 2 feet. .MONDAY NIGHT...Southwest winds 5 to 15 knots backing south after midnight. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots backing east by mid afternoon. A slight chance of showers through early afternoon, then showers likely and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 5 to 15 knots veering south after midnight. Showers and a chance of thunderstorms. Waves calm to 2 feet. .WEDNESDAY...West winds 10 to 20 knots veering northwest. A chance of showers. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots becoming north 5 to 15 knots. Waves calm to 2 feet. $$ LSZ264-232000- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1000 AM EDT Sun Aug 23 2026 .REST OF TODAY...North winds 10 to 20 knots backing northwest late. Waves 3 to 5 feet occasionally to 7 feet subsiding to 1 to 3 feet. .TONIGHT...Northwest winds 10 to 20 knots becoming north 5 to 15 knots late. Waves 1 to 3 feet. .MONDAY...North winds 5 to 15 knots backing west late. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots backing southeast by mid afternoon. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 10 to 20 knots becoming south 5 to 15 knots after midnight. Showers and a chance of thunderstorms. Waves building to 1 to 3 feet. .WEDNESDAY...West winds 5 to 15 knots becoming northwest 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. .THURSDAY...Northwest winds 15 to 25 knots becoming north 5 to 15 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. $$ LSZ265-232000- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1000 AM EDT Sun Aug 23 2026 .REST OF TODAY...North winds 20 to 30 knots backing northwest late. Isolated showers. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...Northwest winds 15 to 25 knots. Waves subsiding to 2 to 4 feet. .MONDAY...North winds 10 to 20 knots backing northwest in the afternoon, then diminishing to 5 to 15 knots late. Waves subsiding to 1 to 3 feet. .MONDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .TUESDAY...South winds 5 to 15 knots becoming southeast 10 to 20 knots by mid afternoon. A chance of showers by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 15 to 25 knots veering south after midnight. Showers and a chance of thunderstorms. Waves building to 1 to 3 feet. .WEDNESDAY...West winds 10 to 20 knots becoming northwest 15 to 25 knots. Showers likely. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .THURSDAY...Northwest gales to 35 knots diminishing to 15 to 25 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to calm to 2 feet. $$ LSZ266-232000- 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- 1000 AM EDT Sun Aug 23 2026 .REST OF TODAY...North winds 20 to 30 knots backing northwest late. Isolated showers. Waves 4 to 7 feet occasionally to 9 feet. .TONIGHT...Northwest winds 20 to 30 knots diminishing to 15 to 25 knots after midnight, then veering north late. Waves subsiding to 3 to 6 feet occasionally to 8 feet, then building to 4 to 7 feet occasionally to 9 feet. .MONDAY...North winds 15 to 25 knots backing northwest in the afternoon, then diminishing to 10 to 20 knots late. Waves subsiding to 2 to 4 feet. .MONDAY NIGHT...Northwest winds 10 to 20 knots becoming west 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .TUESDAY...South winds 5 to 15 knots becoming southeast 10 to 20 knots by mid afternoon. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 15 to 25 knots veering south after midnight. A chance of showers through midnight. A chance of thunderstorms. Showers after midnight. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .WEDNESDAY...South winds 10 to 20 knots becoming northwest 15 to 25 knots. Showers likely. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .THURSDAY...Northwest gales to 35 knots becoming north 15 to 25 knots. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 1 to 3 feet. $$ LSZ267-232000- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadianborder- 1000 AM EDT Sun Aug 23 2026 .REST OF TODAY...Northwest winds 20 to 30 knots increasing to 30 knots with a few gale force gusts to 35 knots possible in the afternoon. Isolated showers. Waves 3 to 6 feet occasionally to 8 feet building to 4 to 7 feet occasionally to 9 feet. .TONIGHT...Northwest winds to 30 knots with a few gale force gusts to 35 knots possible becoming north 20 to 30 knots late. Waves building to 4 to 8 feet occasionally to 10 feet. .MONDAY...North winds 20 to 30 knots becoming northwest 15 to 25 knots in the afternoon. Waves subsiding to 2 to 4 feet. .MONDAY NIGHT...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .TUESDAY...West winds 5 to 15 knots backing east by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 5 to 15 knots becoming south 15 to 25 knots after midnight. A chance of thunderstorms. Showers likely after midnight. Waves building to 2 to 4 feet. .WEDNESDAY...South winds 10 to 20 knots veering west. Showers. A chance of thunderstorms. A chance of showers. Waves subsiding to calm to 2 feet. .THURSDAY...Northwest winds 15 to 25 knots. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. $$ LSZ261-232000- MAFOR 2315/ Superior West 11810 11500 11510 11500 11600 11700 12800. Waves 2 feet or less. Superior North Central 11830 14720 11820 12810. Waves 2 to 4 feet. Superior South Central 12840 13740 11730 12830. Waves 3 to 6 feet. Superior East 14740 11730 11740 12830. Waves 4 to 6 feet. $$ 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