


Great Lakes Forecast
Issued by NWS
Issued by NWS
343 FZUS63 KMQT 031402 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1001 AM EDT Sun Aug 3 2025 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 30.2 inch high pressure over the Great Lakes gradually weakens to 30.1 inches tonight. Meanwhile, a 30.2 inch high over northern Manitoba shifts southeast to northern Ontario. This high pressure will slowly reinvigorate ridging over the Great Lakes into Monday as it builds to 30.4 inches over Quebec by Tuesday morning. At the same time, 29.8 inch troughing sets up over the High Plains. The high briefly builds to 30.5 inches on Wednesday with both features remaining largely stationary. On Thursday, a low of 29.7 inches emerges over Manitoba while the high weakens to 30.3 inches off the New England coast. LSZ162-032000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1001 AM EDT Sun Aug 3 2025 /901 AM CDT Sun Aug 3 2025/ .REST OF TODAY...Southwest winds 5 to 15 knots backing south late. Waves calm to 2 feet. .TONIGHT...Southeast winds 5 to 15 knots backing northeast late. Haze. Waves calm to 2 feet. .MONDAY...East winds 5 to 15 knots. Haze. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves calm to 2 feet. .TUESDAY...East winds 10 to 20 knots. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 10 to 20 knots becoming southeast 5 to 15 knots after midnight. Waves calm to 2 feet. .WEDNESDAY...East winds 10 to 20 knots veering south. A chance of showers and thunderstorms. Waves calm to 2 feet. .THURSDAY...South winds 10 to 20 knots diminishing to 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-032000- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1001 AM EDT Sun Aug 3 2025 .REST OF TODAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet building to 1 to 3 feet. .TONIGHT...Southwest winds 5 to 15 knots becoming south less than 10 knots after midnight. Haze. Waves subsiding to calm to 2 feet. .MONDAY...Southeast winds less than 10 knots backing east in the afternoon, then increasing to 5 to 15 knots late. Haze by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...East winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 5 to 15 knots veering south after midnight. Waves calm to 2 feet. .WEDNESDAY...Southeast winds 5 to 15 knots becoming south 10 to 20 knots. A chance of showers and thunderstorms. Waves building to 1 to 3 feet. .THURSDAY...Southwest winds 5 to 15 knots backing south. Waves subsiding to calm to 2 feet. $$ LSZ264-032000- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1001 AM EDT Sun Aug 3 2025 .REST OF TODAY...West winds 5 to 15 knots backing southwest in the afternoon. Waves 1 to 3 feet. .TONIGHT...Southwest winds 5 to 15 knots becoming south less than 10 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Southeast winds less than 10 knots backing east in the afternoon, then increasing to 5 to 15 knots late. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Southeast winds 5 to 15 knots backing east by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 5 to 15 knots veering south after midnight. Waves calm to 2 feet. .WEDNESDAY...Southeast winds 10 to 20 knots veering south. A chance of showers and thunderstorms. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .THURSDAY...South winds 5 to 15 knots. A chance of showers. Waves subsiding to calm to 2 feet. $$ LSZ265-032000- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1001 AM EDT Sun Aug 3 2025 .REST OF TODAY...West winds 10 to 20 knots diminishing to 5 to 15 knots late. Waves calm to 2 feet. .TONIGHT...South winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY...East winds 5 to 15 knots. Haze by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots veering southeast after midnight. Waves calm to 2 feet. .TUESDAY...Southeast winds 5 to 15 knots becoming east 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 10 to 20 knots veering south after midnight. Waves calm to 2 feet. .WEDNESDAY...Southeast winds 10 to 20 knots veering south. Waves calm to 2 feet. .THURSDAY...South winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. $$ LSZ266-032000- 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 Sun Aug 3 2025 .REST OF TODAY...West winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon. Waves 1 to 3 feet subsiding to calm to 2 feet. .TONIGHT...South winds 5 to 15 knots backing southeast after midnight. Haze after midnight. Waves calm to 2 feet. .MONDAY...Southeast winds 5 to 15 knots backing east in the afternoon. Haze. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Southeast winds 5 to 15 knots becoming east 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves calm to 2 feet. .WEDNESDAY...Southeast winds 10 to 20 knots veering south. Waves building to 1 to 3 feet. .THURSDAY...South winds 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. $$ LSZ267-032000- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 1001 AM EDT Sun Aug 3 2025 .REST OF TODAY...West winds 10 to 20 knots diminishing to 5 to 15 knots late. Waves 1 to 3 feet subsiding to calm to 2 feet. .TONIGHT...South winds 5 to 15 knots backing southeast after midnight. Waves calm to 2 feet. .MONDAY...East winds 5 to 15 knots. Haze through early afternoon. Waves calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots veering southeast after midnight. Waves calm to 2 feet. .TUESDAY...Southeast winds 10 to 20 knots backing east by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...Southeast winds 10 to 20 knots. Waves calm to 2 feet. .WEDNESDAY...Southeast winds 10 to 20 knots. Waves building to 1 to 3 feet. .THURSDAY...South winds 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. $$ LSZ261-032000- MAFOR 0315/ Superior West 11510 11500 14400 12300. Waves 2 feet or less. Superior North Central 11610 13510 11500 12400 11300. Waves 1 to 3 feet subsiding to 1 foot or less this afternoon and tonight. Waves 1 foot or less Monday morning. Superior South Central 11610 11700 11800 11300 11400 13300. Waves 2 feet or less. Superior East 12610 11600 11500 11400 12300 11200. Waves 1 to 3 feet this afternoon and tonight. Waves 1 foot or less Monday 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