Great Lakes Forecast
Issued by NWS
Issued by NWS
772 FZUS63 KMQT 150801 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 401 AM EDT Sat Aug 15 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... 30.2 inch high pressure just north and east of Lake Superior eventually gives way to a 29.9 inch low by tonight as the aforementioned high moves east towards New England. This low deepens to 29.7 inches as it reaches Quebec Sunday night. Into Monday, a 30.1 inch high over the Plains weakens to 30.0 inches as it slides generally south of the Great Lakes Tuesday. Meanwhile Tuesday, a 29.4 inch low over Hudson Bay extends a 29.8 inch trough over Lake Superior. Wednesday into Thursday morning, ridging of 30.1 inches moves over the Upper Great Lakes from the Plains. LSZ162-152000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 401 AM EDT Sat Aug 15 2026 /301 AM CDT Sat Aug 15 2026/ .EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...East winds 10 to 20 knots backing northeast in the afternoon. A chance of showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TONIGHT...Northeast winds 5 to 15 knots backing north after midnight, then backing west late. A chance of showers and a slight chance of thunderstorms through midnight. Waves calm to 2 feet. .SUNDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots late. Waves calm to 2 feet. .SUNDAY NIGHT...West winds 5 to 15 knots veering northwest after midnight. Waves calm to 2 feet. .MONDAY...West winds 5 to 15 knots becoming southwest 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southwest winds 10 to 20 knots veering west after midnight. A chance of showers. Waves calm to 2 feet. .TUESDAY...West winds 5 to 15 knots veering north. A chance of showers. Waves calm to 2 feet. .WEDNESDAY...North winds 5 to 15 knots backing northwest. Waves calm to 2 feet. $$ LSZ263-152000- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 401 AM EDT Sat Aug 15 2026 .EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...East winds 5 to 15 knots increasing to 10 to 20 knots late. A chance of showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TONIGHT...East winds 10 to 20 knots becoming northwest 5 to 15 knots after midnight, then backing west late. A slight chance of thunderstorms through midnight. A chance of showers. Waves calm to 2 feet. .SUNDAY...West winds 10 to 20 knots. Waves calm to 2 feet. .SUNDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY...West winds 5 to 15 knots becoming southwest 15 to 25 knots by mid afternoon. Waves building to 2 to 4 feet. .MONDAY NIGHT...Southwest winds 10 to 20 knots veering west after midnight. A chance of showers. Waves subsiding to calm to 2 feet. .TUESDAY...West winds 5 to 15 knots becoming north 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .WEDNESDAY...North winds 10 to 20 knots becoming northwest 5 to 15 knots. Waves calm to 2 feet. $$ LSZ264-152000- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 401 AM EDT Sat Aug 15 2026 .EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...East winds 5 to 15 knots increasing to 10 to 20 knots late. A chance of showers by mid afternoon. Waves calm to 2 feet. .TONIGHT...East winds 10 to 20 knots veering southeast after midnight, then becoming west 5 to 15 knots late. Showers likely and a slight chance of thunderstorms through midnight, then a slight chance of showers after midnight. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots backing west late. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SUNDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY...West winds 5 to 15 knots becoming southwest 10 to 20 knots by mid afternoon. Waves building to 1 to 3 feet. .MONDAY NIGHT...Southwest winds 10 to 20 knots. A chance of showers. Waves subsiding to calm to 2 feet. .TUESDAY...West winds 5 to 15 knots veering north. Waves calm to 2 feet. .WEDNESDAY...North winds 10 to 20 knots becoming northwest 5 to 15 knots. Waves calm to 2 feet. $$ LSZ265-152000- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 401 AM EDT Sat Aug 15 2026 .EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...Southeast winds 5 to 15 knots becoming east 10 to 20 knots in the afternoon, then increasing to 15 to 25 knots late. Waves building to 1 to 3 feet. .TONIGHT...Southeast winds 15 to 25 knots becoming south 10 to 20 knots after midnight, then veering west late. A chance of showers and a slight chance of thunderstorms. Waves subsiding to calm to 2 feet. .SUNDAY...Northwest winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .SUNDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .MONDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...South winds 10 to 20 knots becoming southwest 15 to 25 knots after midnight. Waves calm to 2 feet. .TUESDAY...West winds 10 to 20 knots veering north. A chance of showers. Waves calm to 2 feet. .WEDNESDAY...North winds 15 to 25 knots becoming northwest 10 to 20 knots. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. $$ LSZ266-152000- 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- 401 AM EDT Sat Aug 15 2026 .EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...East winds 5 to 15 knots increasing to 10 to 20 knots late. Waves calm to 2 feet. .TONIGHT...East winds 10 to 20 knots becoming southeast 15 to 25 knots after midnight, then becoming south 10 to 20 knots late. A chance of showers and a slight chance of thunderstorms. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon. A slight chance of showers through early afternoon. Waves building to 3 to 5 feet occasionally to 7 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...West winds 5 to 15 knots backing southwest by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...South winds 5 to 15 knots becoming southwest 15 to 25 knots after midnight. Waves calm to 2 feet. .TUESDAY...West winds 10 to 20 knots veering north. A chance of showers. Waves calm to 2 feet. .WEDNESDAY...North winds 15 to 25 knots diminishing to 10 to 20 knots. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. $$ LSZ267-152000- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 401 AM EDT Sat Aug 15 2026 .EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...East winds 5 to 15 knots increasing to 10 to 20 knots late. Waves calm to 2 feet. .TONIGHT...Southeast winds 10 to 20 knots veering south late. A slight chance of showers through midnight, then showers likely and a chance of thunderstorms after midnight. Waves building to 1 to 3 feet. .SUNDAY...West winds 10 to 20 knots becoming northwest 15 to 25 knots in the afternoon, then increasing to 20 to 30 knots late. A chance of showers and a slight chance of thunderstorms through early afternoon. Waves subsiding to calm to 2 feet, then building to 3 to 5 feet occasionally to 7 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...West winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY NIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves calm to 2 feet. .TUESDAY...West winds 5 to 15 knots veering north. A chance of showers. Waves calm to 2 feet. .WEDNESDAY...North winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. $$ LSZ261-151400- MAFOR 1509/ Superior West 13210 11110 12120 11100 11700. A chance of showers this afternoon and tonight. Waves 1 to 2 feet. Superior North Central 11200 11300 13210 11226 11326 11410. Waves 1 foot or less today. Waves 1 to 3 feet tonight. Superior South Central 11200 11310 12220 11230 11330 11336 11426. Waves 2 feet or less today. Waves 1 to 3 feet tonight. Superior East 14200 11210 11220 11320 11326. A chance of thunderstorms overnight. Waves 1 foot or less today. Waves 1 to 3 feet tonight. $$ 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