FZUS63 KMQT 232001 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 400 PM 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 afternoon, a 29.6 inch low is along the Quebec/Ontario line while 30.0 inch high pressure extends from Hudson Bay to Missouri. Little movement is expected with only a slight weakening of both pressure centers through 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. LSZ162-240800- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 400 PM EDT Sun Aug 23 2026 /300 PM CDT Sun Aug 23 2026/ .LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...Southwest winds 5 to 15 knots veering north after midnight. 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 diminishing to less than 10 knots after midnight, then backing east late. 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 slight chance of showers through early afternoon. A chance of thunderstorms. Showers likely by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 5 to 15 knots veering west after midnight. Showers through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 10 to 20 knots. Waves calm to 2 feet. .THURSDAY...Northwest winds 5 to 15 knots veering north. Waves calm to 2 feet. .FRIDAY...Northeast winds 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-240800- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 400 PM EDT Sun Aug 23 2026 .LATE THIS AFTERNOON...West winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...West winds 5 to 15 knots veering northwest after midnight. Waves calm to 2 feet. .MONDAY...North winds 5 to 15 knots backing southwest late. Waves calm to 2 feet. .MONDAY NIGHT...Southwest winds 5 to 15 knots backing south late. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots backing southeast by mid afternoon. Showers likely and a chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 5 to 15 knots veering southwest after midnight. Showers and a chance of thunderstorms. Waves calm to 2 feet. .WEDNESDAY...West winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 10 to 20 knots. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots becoming north 5 to 15 knots. Waves calm to 2 feet. .FRIDAY...North winds 5 to 15 knots veering south. Waves calm to 2 feet. $$ LSZ264-240800- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 400 PM EDT Sun Aug 23 2026 .LATE THIS AFTERNOON...Northwest winds 10 to 20 knots. Waves 1 to 3 feet. .TONIGHT...Northwest winds 10 to 20 knots becoming north 5 to 15 knots late. Waves subsiding to calm to 2 feet. .MONDAY...North winds 5 to 15 knots backing west late. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .MONDAY NIGHT...West winds 5 to 15 knots diminishing to less than 10 knots after midnight, then backing southwest late. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots backing southeast by mid afternoon. A chance of showers 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 building to 1 to 3 feet. .WEDNESDAY...Southwest winds 10 to 20 knots veering west by mid afternoon. A chance of showers. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves calm to 2 feet. .THURSDAY...Northwest winds 10 to 20 knots becoming north 5 to 15 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .FRIDAY...North winds 5 to 15 knots backing southwest. Waves calm to 2 feet. $$ LSZ265-240800- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 400 PM EDT Sun Aug 23 2026 .LATE THIS AFTERNOON...Northwest winds 20 to 30 knots. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...Northwest winds 15 to 25 knots. Waves subsiding to 2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet. .MONDAY...North winds 15 to 25 knots diminishing to 5 to 15 knots. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...Northwest winds 5 to 15 knots backing southwest late. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots becoming southeast 10 to 20 knots by mid afternoon. A chance of showers and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...South winds 15 to 25 knots. Showers and a chance of thunderstorms. Waves building to 1 to 3 feet. .WEDNESDAY...Southwest winds 15 to 25 knots becoming west 10 to 20 knots by mid afternoon. Showers likely through early afternoon. A chance of showers by mid afternoon. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 15 to 25 knots increasing to 20 to 30 knots after midnight. Waves building to 2 to 4 feet. .THURSDAY...Northwest winds 20 to 30 knots becoming north 10 to 20 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to calm to 2 feet. .FRIDAY...North winds 10 to 20 knots backing southwest. Waves calm to 2 feet. $$ LSZ266-240800- 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- 400 PM EDT Sun Aug 23 2026 .LATE THIS AFTERNOON...Northwest winds 20 to 30 knots. A slight chance of showers. Waves 4 to 7 feet occasionally to 9 feet subsiding to 3 to 6 feet occasionally to 8 feet. .TONIGHT...Northwest winds 20 to 30 knots becoming north 15 to 25 knots after midnight. Waves 3 to 6 feet occasionally to 8 feet. .MONDAY...North winds 15 to 25 knots backing northwest in the afternoon, then diminishing to 10 to 20 knots late. Waves subsiding to 1 to 3 feet. .MONDAY NIGHT...Northwest winds 5 to 15 knots backing west late. 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 veering west by mid afternoon. Showers through early afternoon. A chance of showers by mid afternoon. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 15 to 25 knots increasing to 20 to 30 knots after midnight. Waves building to 2 to 4 feet. .THURSDAY...Northwest winds 20 to 30 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. .FRIDAY...North winds 5 to 15 knots backing west. Waves subsiding to calm to 2 feet. $$ LSZ267-240800- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 400 PM EDT Sun Aug 23 2026 .LATE THIS AFTERNOON...Northwest winds 20 to 30 knots. A slight chance of showers. Waves 4 to 7 feet occasionally to 9 feet. .TONIGHT...Northwest winds 20 to 30 knots increasing to 30 knots with a few gale force gusts to 35 knots possible after midnight, then becoming north 20 to 30 knots late. A slight chance of showers through midnight. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .MONDAY...North winds 20 to 30 knots becoming northwest 15 to 25 knots in the afternoon. Waves subsiding to 2 to 4 feet. .MONDAY NIGHT...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .TUESDAY...Southwest winds 5 to 15 knots backing east by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...South winds 10 to 20 knots increasing to 15 to 25 knots after midnight. A chance of showers through midnight. Showers after midnight. Waves building to 2 to 4 feet. .WEDNESDAY...South winds 15 to 25 knots diminishing to 10 to 20 knots by mid afternoon. Showers and a chance of thunderstorms. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...West winds 10 to 20 knots veering northwest after midnight. A chance of showers. Waves calm to 2 feet. .THURSDAY...Northwest winds 15 to 25 knots becoming north 10 to 20 knots. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .FRIDAY...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots. Waves subsiding to calm to 2 feet. $$ LSZ261-240200- MAFOR 2321/ Superior West 11510 11500 11600 11700 12800 11100 11400. Waves 1 foot or less. Superior North Central 13720 11820 12810 12710. Waves 1 to 3 feet. Superior South Central 11730 12740 11730 11720 12830 11720. Waves 3 to 5 feet tonight. Waves 2 to 4 feet Monday. Superior East 11740 12730 13830 11730 11720. Waves 3 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