Great Lakes Forecast
Issued by NWS
Issued by NWS
391 FZUS63 KMQT 182211 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 611 PM EDT Sat May 18 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 29.5 inch low over southern Manitoba tracks northeast over far northwestern Ontario while deepening to 29.4 inches tonight before weakening to 29.6 inches over Hudson Bay on Sunday. An associated 29.6 inch trough sweeps across western Lake Superior this evening before weakening to 29.9 inches while sailing across far eastern Lake Superior late tonight. By Sunday morning, a 30.0 inch high pressure ridge settles over Wisconsin and gradually shifts east over Southern Ontario by Monday morning. Ridging is displaced by a broad 29.8 inch trough tracking northeast across the Upper Great Lakes from the Central Plains Monday evening. On Tuesday, a 29.5 inch low pressure tracks northeast to the Upper Mississippi Valley while deepening to 29.1 inches. This low tracks across western Lake Superior Wednesday or Wednesday night before weakening to 29.4 inches over Ontario on Thursday. LSZ162-190615- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 611 PM EDT Sat May 18 2024 /511 PM CDT Sat May 18 2024/ .LATE THIS AFTERNOON...North winds 10 to 20 knots. Scattered showers and thunderstorms. Waves 1 to 3 feet. .TONIGHT...West winds 15 to 25 knots becoming southwest 10 to 20 knots late. Waves building to 2 to 4 feet. .SUNDAY...Southwest winds 10 to 20 knots. Waves subsiding to 1 to 3 feet, then building to 2 to 4 feet. .SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming south 5 to 15 knots after midnight, then becoming east 10 to 20 knots late. A chance of showers. Waves subsiding to calm to 2 feet. .MONDAY...Northeast winds 10 to 20 knots. A chance of rain showers. Waves calm to 2 feet. .MONDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Northeast winds 10 to 20 knots increasing to 15 to 25 knots by mid afternoon. A chance of rain showers. Waves building to 3 to 5 feet occasionally to 7 feet. .TUESDAY NIGHT...Northeast winds 20 to 30 knots increasing to gales to 35 knots after midnight. Showers. Waves building to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...Southwest winds 20 to 30 knots becoming west 15 to 25 knots. Showers likely, then a chance of showers. Waves subsiding to 2 to 4 feet. .THURSDAY...West winds 15 to 25 knots becoming north 10 to 20 knots. A chance of rain showers. Waves subsiding to calm to 2 feet. $$ LSZ263-190615- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 611 PM EDT Sat May 18 2024 ...SEVERE THUNDERSTORM WATCH 257 IN EFFECT UNTIL 11 PM EDT THIS EVENING... .LATE THIS AFTERNOON...West winds 10 to 20 knots. Numerous rain showers and scattered thunderstorms. Some thunderstorms may be severe with wind gusts over 35 knots and large hail. Waves 2 to 4 feet. .TONIGHT...Southwest winds 10 to 20 knots veering west after midnight, then backing southwest late. A slight chance of showers and thunderstorms through midnight. Waves 2 to 4 feet. .SUNDAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots in the afternoon. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming south 5 to 15 knots after midnight. A slight chance of showers after midnight. Waves subsiding to calm to 2 feet. .MONDAY...East winds 5 to 15 knots backing northeast by mid afternoon. A chance of rain showers. Waves calm to 2 feet. .MONDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...Northeast winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. A chance of rain showers. Waves building to 2 to 4 feet. .TUESDAY NIGHT...Northeast winds 20 to 30 knots. Showers. Waves building to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...Southwest winds 20 to 30 knots becoming west 10 to 20 knots. Rain showers likely, then a chance of rain showers. Waves building to 6 to 9 feet occasionally to 11 feet, then subsiding to 3 to 5 feet occasionally to 7 feet. .THURSDAY...West winds 10 to 20 knots becoming north 5 to 15 knots. Waves subsiding to calm to 2 feet. $$ LSZ264-190615- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 611 PM EDT Sat May 18 2024 .LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Scattered showers and thunderstorms. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...Southwest winds 10 to 20 knots veering west after midnight. A chance of showers and thunderstorms through midnight. Waves subsiding to 2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet. .SUNDAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots in the afternoon. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming south 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Southeast winds 5 to 15 knots backing east by mid afternoon. A chance of rain showers. Waves calm to 2 feet. .MONDAY NIGHT...North winds 5 to 15 knots backing northwest after midnight. Waves calm to 2 feet. .TUESDAY...North winds 5 to 15 knots becoming northeast 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 15 to 25 knots increasing to 20 to 30 knots after midnight. Showers. Waves building to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...Southwest winds 20 to 30 knots becoming west 10 to 20 knots. Rain showers likely, then a chance of rain showers. Waves building to 6 to 9 feet occasionally to 11 feet, then subsiding to 3 to 5 feet occasionally to 7 feet. .THURSDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots. Waves subsiding to 1 to 3 feet. $$ LSZ265-190615- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 611 PM EDT Sat May 18 2024 .LATE THIS AFTERNOON...Southeast winds 15 to 25 knots. Scattered showers and thunderstorms. Waves 2 to 4 feet. .TONIGHT...South winds 10 to 20 knots becoming west 15 to 25 knots after midnight, then diminishing to 10 to 20 knots late. Showers with thunderstorms likely through midnight. Waves subsiding to 1 to 3 feet. .SUNDAY...Southwest winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...South winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. A slight chance of showers after midnight. Waves calm to 2 feet. .MONDAY...Southeast winds 10 to 20 knots. Rain showers likely through early afternoon, then a chance of rain showers and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to 2 feet. .TUESDAY...North winds 5 to 15 knots becoming east 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 10 to 20 knots increasing to 20 to 30 knots after midnight. Showers. Waves building to 3 to 5 feet occasionally to 7 feet. .WEDNESDAY...Southwest winds 20 to 30 knots becoming west 15 to 25 knots. A chance of showers. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to calm to 2 feet. .THURSDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. Waves calm to 2 feet. $$ LSZ266-190615- 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- 611 PM EDT Sat May 18 2024 .LATE THIS AFTERNOON...Southeast winds 20 to 30 knots. Scattered showers and isolated thunderstorms. Waves 3 to 6 feet occasionally to 8 feet. .TONIGHT...South winds 15 to 25 knots becoming southwest 10 to 20 knots after midnight, then veering west late. A chance of showers and thunderstorms through midnight. Waves subsiding to 2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet. .SUNDAY...West winds 10 to 20 knots backing southwest in the afternoon. Waves 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .SUNDAY NIGHT...Southwest winds 5 to 15 knots becoming south 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Southeast winds 10 to 20 knots. A chance of rain showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southeast winds 5 to 15 knots backing north after midnight. Waves calm to 2 feet. .TUESDAY...North winds 5 to 15 knots becoming northeast 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 15 to 25 knots increasing to 20 to 30 knots after midnight. Showers and a chance of thunderstorms. Waves building to 3 to 6 feet occasionally to 8 feet. .WEDNESDAY...Southwest winds 20 to 30 knots diminishing to 15 to 25 knots. A chance of rain showers. Waves building to 5 to 8 feet occasionally to 10 feet, then subsiding to 3 to 5 feet occasionally to 7 feet. .THURSDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots. Waves subsiding to 1 to 3 feet. $$ LSZ267-190615- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 611 PM EDT Sat May 18 2024 .LATE THIS AFTERNOON...South winds 15 to 25 knots. Waves 1 to 3 feet building to 2 to 4 feet. .TONIGHT...South winds 15 to 25 knots becoming west 10 to 20 knots late. Showers likely through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves subsiding to 1 to 3 feet. .SUNDAY...West winds 10 to 20 knots becoming southwest 5 to 15 knots in the afternoon. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots after midnight. Waves calm to 2 feet. .MONDAY...Southeast winds 10 to 20 knots. A chance of showers through early afternoon, then showers likely and a slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .MONDAY NIGHT...Southeast winds 10 to 20 knots veering northwest after midnight. A chance of showers. Waves calm to 2 feet. .TUESDAY...North winds 10 to 20 knots veering northeast by mid afternoon. Waves calm to 2 feet. .TUESDAY NIGHT...East winds 10 to 20 knots becoming southeast 20 to 30 knots after midnight. Showers and a chance of thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet. .WEDNESDAY...Southwest winds 20 to 30 knots diminishing to 15 to 25 knots. Rain showers likely, then a chance of rain showers. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. .THURSDAY...West winds 10 to 20 knots. A chance of rain showers. Waves subsiding to 1 to 3 feet. $$ LSZ261-190615- MAFOR 1821 AMD/ Superior West...SEVERE THUNDERSTORM WATCH IN EFFECT...11710 19719 11520 12620 14520. Waves 2 to 4 feet. Superior North Central 11340 19349 11426 19429 11520 12620 13530. Waves 3 to 6 feet. Superior South Central 11340 19346 11426 19429 11520 19526 12620 12610 11510. Waves 2 to 4 feet subsiding to 1 to 3 feet tonight. Waves 1 to 3 feet Sunday. Superior East 11420 11420 19429 11426 19429 11520 11620 11610 12510. Waves 2 to 4 feet. $$ 07 Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes