FZUS63 KMQT 180201 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1001 PM EDT Mon Aug 17 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 29.5 inch low will remain over the Hudson Bay through Thursday before shifting east away from the region. This will extend troughing of 29.9 inches over Lake Superior tonight through Tuesday afternoon, then weak 29.9 inch ridging returns to Lake Superior Tuesday night. A 30.0 inch high pressure settles over the Northern Plains Tuesday afternoon and night, eventually moving over Lake Superior Wednesday evening before expanding to cover much of the Great Lakes by Thursday afternoon. Friday into the weekend, a low pressure of around 29.8 inches transits across northern Ontario quickly followed by 30.2 inch ridging for the latter part of the weekend into next week. LSZ162-180800- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1001 PM EDT Mon Aug 17 2026 /901 PM CDT Mon Aug 17 2026/ .REST OF TONIGHT...Southwest winds 10 to 20 knots veering west after midnight. A chance of showers and a slight chance of thunderstorms by midnight. Waves calm to 2 feet. .TUESDAY...Northwest winds 5 to 15 knots becoming southwest 10 to 20 knots in the afternoon. 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 southwest by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southwest winds 5 to 15 knots becoming north less than 10 knots after midnight. Waves calm to 2 feet. .THURSDAY...Southeast winds less than 10 knots becoming east 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Southeast winds 5 to 15 knots backing north after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...West winds 5 to 15 knots becoming northwest 10 to 20 knots. Waves calm to 2 feet. .SATURDAY...North winds 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-180800- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1001 PM EDT Mon Aug 17 2026 .REST OF TONIGHT...Southwest winds 10 to 20 knots veering west after midnight. A slight chance of thunderstorms by midnight. A chance of showers. Waves 1 to 3 feet. .TUESDAY...Northwest winds 10 to 20 knots becoming west 5 to 15 knots in the afternoon, then becoming southwest 10 to 20 knots late. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .TUESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight, then veering northwest late. Waves subsiding to calm to 2 feet. .WEDNESDAY...Northwest winds 5 to 15 knots backing southwest by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southwest winds 5 to 15 knots becoming south less than 10 knots after midnight. Waves calm to 2 feet. .THURSDAY...South winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY NIGHT...South winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .FRIDAY...West winds 10 to 20 knots veering north. Waves calm to 2 feet. .SATURDAY...North winds 10 to 20 knots. Waves calm to 2 feet. $$ LSZ264-180800- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1001 PM EDT Mon Aug 17 2026 .REST OF TONIGHT...Southwest winds 5 to 15 knots increasing to 10 to 20 knots after midnight, then veering west late. A slight chance of thunderstorms by midnight. A slight chance of showers. Waves 1 to 3 feet. .TUESDAY...Northwest winds 10 to 20 knots becoming west 5 to 15 knots in the afternoon, then becoming southwest 10 to 20 knots late. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .TUESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight, then veering northwest late. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .WEDNESDAY...Northwest winds 5 to 15 knots backing west by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...Southwest winds 5 to 15 knots diminishing to less than 10 knots after midnight. Waves calm to 2 feet. .THURSDAY...South winds less than 10 knots increasing to 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...South winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .FRIDAY...Southwest winds 10 to 20 knots becoming north 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .SATURDAY...North winds 10 to 20 knots. Waves calm to 2 feet. $$ LSZ265-180800- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1001 PM EDT Mon Aug 17 2026 .REST OF TONIGHT...South winds 10 to 20 knots becoming southwest 15 to 25 knots after midnight, then veering west late. A slight chance of showers. Waves calm to 2 feet building to 1 to 3 feet. .TUESDAY...West winds 20 to 30 knots becoming northwest 15 to 25 knots in the afternoon, then backing west late. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .TUESDAY NIGHT...West winds 10 to 20 knots increasing to 15 to 25 knots after midnight, then diminishing to 10 to 20 knots late. Waves calm to 2 feet. .WEDNESDAY...Northwest winds 10 to 20 knots veering north by mid afternoon. Waves calm to 2 feet. .WEDNESDAY NIGHT...South winds 5 to 15 knots becoming southwest 10 to 20 knots after midnight. Waves calm to 2 feet. .THURSDAY...Southwest winds 5 to 15 knots backing southeast by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...South winds 10 to 20 knots increasing to 15 to 25 knots after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...South winds 15 to 25 knots becoming northwest 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet. .SATURDAY...North winds 20 to 30 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. $$ LSZ266-180800- 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 PM EDT Mon Aug 17 2026 .REST OF TONIGHT...South winds 10 to 20 knots increasing to 15 to 25 knots after midnight, then veering west late. A slight chance of showers. Waves calm to 2 feet building to 1 to 3 feet. .TUESDAY...West winds 15 to 25 knots veering northwest in the afternoon, then becoming west 10 to 20 knots late. A slight chance of showers through early afternoon. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .TUESDAY NIGHT...West winds 10 to 20 knots veering northwest late. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .WEDNESDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet. .WEDNESDAY NIGHT...West winds 5 to 15 knots backing southwest after midnight. Waves calm to 2 feet. .THURSDAY...Southwest winds 5 to 15 knots backing southeast by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...South winds 10 to 20 knots increasing to 15 to 25 knots after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...South winds 10 to 20 knots backing north. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SATURDAY...North winds 20 to 30 knots diminishing to 15 to 25 knots. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. $$ LSZ267-180800- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 1001 PM EDT Mon Aug 17 2026 .REST OF TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots after midnight, then veering southwest late. A chance of showers after midnight. Waves calm to 2 feet building to 1 to 3 feet. .TUESDAY...West winds 10 to 20 knots increasing to 15 to 25 knots in the afternoon, then diminishing to 10 to 20 knots late. A slight chance of showers through early afternoon. Waves 1 to 3 feet. .TUESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet. .WEDNESDAY NIGHT...Northwest winds 5 to 15 knots backing west after midnight. Waves calm to 2 feet. .THURSDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY NIGHT...Southeast winds 5 to 15 knots becoming south 10 to 20 knots after midnight. A chance of showers. Waves calm to 2 feet. .FRIDAY...South winds 10 to 20 knots veering southwest. Showers likely. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SATURDAY...North winds 15 to 25 knots. Waves building to 3 to 5 feet occasionally to 7 feet. $$ LSZ261-180800- MAFOR 1803/ Superior West 11520 12620 11710 11610 13520. A chance of showers late this evening. Waves 2 feet or less. Superior North Central 11520 12620 12720 11620 11520 11620. Waves 1 to 3 feet overnight and Tuesday. Waves 2 to 4 feet Tuesday evening. Superior South Central 11420 11530 12630 12730 11720 11620. Waves 1 to 3 feet overnight. Waves 2 to 4 feet subsiding to 1 to 3 feet Tuesday. Waves 1 to 2 feet Tuesday evening. Superior East 12420 11520 11620 11710 12620 11610. A chance of showers overnight and Tuesday morning. Waves 1 to 3 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