Great Lakes Forecast
Issued by NWS
Issued by NWS
944 FZUS63 KMQT 210757 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 357 AM EDT Sat Sep 21 2024 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 29.7 inch trough moving across Lake Superior will dissipate early today, allowing weak 29.9 inch ridging to anchor over the Upper Great Lakes this morning. A new low pressure of 29.6 inches over southern Manitoba this morning will then track across far northern Ontario this afternoon and tonight. Its associated 29.9 inch trough will sweep across Lake Superior during tonight and Sunday morning. In its wake, 30.1 inch high pressure will build from the Northern Plains into northern Ontario during Sunday and Monday. Also on Monday, a 29.7 inch low pressure will track northeast to southern Wisconsin. 30.0 inch high pressure builds over the Lower MS Valley Tuesday, building to 30.1 inches Wednesday. LSZ162-211600- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 357 AM EDT Sat Sep 21 2024 /257 AM CDT Sat Sep 21 2024/ .EARLY THIS MORNING...Southwest winds 5 to 15 knots. A slight chance of showers. Waves calm to 2 feet. .TODAY...Southeast winds 5 to 15 knots becoming east 10 to 20 knots in the afternoon, then backing northeast late. A chance of showers and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TONIGHT...Northwest winds 10 to 20 knots increasing to 20 to 30 knots after midnight, then diminishing to 15 to 25 knots late. A slight chance of showers and thunderstorms through midnight. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .SUNDAY...Northwest winds 15 to 25 knots becoming west 10 to 20 knots late. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY...North winds 5 to 15 knots becoming southeast 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southeast winds 5 to 15 knots veering south after midnight. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots veering west. Waves calm to 2 feet. .WEDNESDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet. $$ LSZ263-211600- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 357 AM EDT Sat Sep 21 2024 .EARLY THIS MORNING...Southwest winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...South winds 5 to 15 knots becoming southeast 10 to 20 knots in the afternoon. A chance of showers and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .TONIGHT...Southwest winds 10 to 20 knots becoming northwest 15 to 25 knots after midnight. A chance of showers and thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet. .SUNDAY...Northwest winds 15 to 25 knots becoming west 10 to 20 knots late. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...North winds 5 to 15 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .MONDAY...North winds 5 to 15 knots veering east by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southeast winds 5 to 15 knots veering south after midnight. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots veering southwest. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots backing southwest. Waves calm to 2 feet. $$ LSZ264-211600- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 357 AM EDT Sat Sep 21 2024 .EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...Southwest winds 5 to 15 knots backing southeast in the afternoon. A slight chance of showers and thunderstorms by mid afternoon. Waves building to 1 to 3 feet. .TONIGHT...South winds 10 to 20 knots becoming northwest 15 to 25 knots after midnight. A chance of showers and a slight chance of thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet. .SUNDAY...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots late. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 1 to 3 feet. .SUNDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .MONDAY...North winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY NIGHT...Southeast winds 5 to 15 knots veering south after midnight. Waves calm to 2 feet. .TUESDAY...South winds 5 to 15 knots. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots backing southwest. Waves calm to 2 feet. $$ LSZ265-211600- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 357 AM EDT Sat Sep 21 2024 .EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...Southwest winds 5 to 15 knots backing southeast in the afternoon, then increasing to 10 to 20 knots late. Waves building to 1 to 3 feet. .TONIGHT...South winds 10 to 20 knots veering west after midnight, then becoming northwest 15 to 25 knots late. A chance of showers and thunderstorms. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .SUNDAY...Northwest winds 20 to 30 knots diminishing to 15 to 25 knots late. A slight chance of showers through early afternoon. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots veering north after midnight. Waves 1 to 3 feet. .MONDAY...North winds 10 to 20 knots veering northeast by mid afternoon. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...East winds 5 to 15 knots veering southeast after midnight. Waves calm to 2 feet. .TUESDAY...East winds 5 to 15 knots veering west. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots. Waves calm to 2 feet. $$ LSZ266-211600- 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- 357 AM EDT Sat Sep 21 2024 .EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...West winds 5 to 15 knots backing southeast in the afternoon, then increasing to 10 to 20 knots late. Waves building to 1 to 3 feet. .TONIGHT...South winds 10 to 20 knots veering southwest after midnight, then becoming northwest 15 to 25 knots late. A chance of showers and thunderstorms. Waves building to 3 to 6 feet occasionally to 8 feet. .SUNDAY...Northwest winds 20 to 30 knots. A chance of showers and a slight chance of thunderstorms through early afternoon. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .SUNDAY NIGHT...North winds 15 to 25 knots. Waves subsiding to 2 to 4 feet. .MONDAY...North winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...Northeast winds 5 to 15 knots veering east after midnight. Waves calm to 2 feet. .TUESDAY...East winds 5 to 15 knots veering west. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots. Waves calm to 2 feet. $$ LSZ267-211600- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 357 AM EDT Sat Sep 21 2024 .EARLY THIS MORNING...Southwest winds 5 to 15 knots. Waves calm to 2 feet. .TODAY...Southwest winds 5 to 15 knots backing southeast in the afternoon, then backing east late. Waves calm to 2 feet. .TONIGHT...South winds 10 to 20 knots veering southwest late. A chance of showers and a slight chance of thunderstorms. Waves building to 2 to 4 feet. .SUNDAY...Northwest winds 10 to 20 knots increasing to 20 to 30 knots. Showers likely through early afternoon. A slight chance of thunderstorms. A slight chance of showers by mid afternoon. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .SUNDAY NIGHT...North winds 15 to 25 knots. A slight chance of showers through midnight. Waves subsiding to 2 to 4 feet. .MONDAY...North winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .MONDAY NIGHT...Northeast winds 10 to 20 knots becoming east 5 to 15 knots after midnight. Waves calm to 2 feet. .TUESDAY...East winds 5 to 15 knots backing northwest. Waves calm to 2 feet. .WEDNESDAY...West winds 5 to 15 knots becoming northwest 10 to 20 knots. Waves calm to 2 feet. $$ LSZ261-211600- MAFOR 2109/ Superior West 11500 11400 11310 11220 11320 11620 12730. A chance of showers this afternoon. A chance of showers and thunderstorms this evening. Waves 1 foot or less today. Waves 1 to 3 feet building to 3 to 5 feet tonight. Superior North Central 11600 11500 11300 11310 11320 11420 11620 11730. A chance of showers tonight. Waves 1 to 2 feet today. Waves 1 to 3 feet building to 3 to 5 feet tonight. Superior South Central 12600 11400 11310 11320 11420 11520 11620. A chance of showers this evening, then a chance of showers and thunderstorms overnight. Waves 2 feet or less today. Waves 2 to 4 feet tonight. Superior East 11500 11600 11400 11300 12310 11420 11510. A chance of showers 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