Great Lakes Forecast
Issued by NWS
Issued by NWS
651 FZUS63 KMQT 202005 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 405 PM EDT Thu Jun 20 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...High pressure of 30.4 inches centered near Isle Royale will weaken to 30.2 inches as it very slowly drifts southeast across central and eastern Lake Superior tonight and Friday. On Saturday, the high will transition to ridging of 30.0 inches extending from northern Ontario across southern Quebec. Meanwhile, 29.7 low pressure developing over eastern Colorado on Friday will track northeast to Wisconsin by Saturday evening. The low will then deepen to 29.5 inches as it passes near the Straits of Mackinac during Saturday night and reaches southern Quebec during Sunday. In its wake, 29.9 inch high pressure building into the Northern Plains on Sunday will settle over the western Great Lakes region on Monday and then the Appalachians on Tuesday. Back to the northwest, 29.3 inch low pressure over Manitoba Monday night will track east toward James Bay on Tuesday, pushing an associated 29.6 inch trough across Lake Superior. LSZ162-210415- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 405 PM EDT Thu Jun 20 2024 /305 PM CDT Thu Jun 20 2024/ .LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. Waves calm to 2 feet. .TONIGHT...Northeast winds 5 to 15 knots. A slight chance of showers after midnight. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots backing northeast in the afternoon. A chance of showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...Northeast winds 5 to 15 knots veering east after midnight, then becoming northeast 10 to 20 knots late. A chance of showers and a slight chance of thunderstorms. Waves building to 1 to 3 feet. .SATURDAY...Northeast winds 10 to 20 knots. Showers likely and a slight chance of thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .SATURDAY NIGHT...North winds 10 to 20 knots backing west after midnight. A chance of showers. Waves subsiding to calm to 2 feet. .SUNDAY...West winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SUNDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet. .MONDAY...Southwest winds 5 to 15 knots increasing to 10 to 20 knots. A chance of showers and thunderstorms. Waves calm to 2 feet. .TUESDAY...Southwest winds 10 to 20 knots veering northwest. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. $$ LSZ263-210415- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 405 PM EDT Thu Jun 20 2024 .LATE THIS AFTERNOON...East winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...East winds 5 to 15 knots diminishing to less than 10 knots after midnight. A slight chance of showers after midnight. Waves calm to 2 feet. .FRIDAY...East winds less than 10 knots increasing to 5 to 15 knots in the afternoon. A slight chance of showers. Waves calm to 2 feet. .FRIDAY NIGHT...East winds 5 to 15 knots. A chance of showers and a slight chance of thunderstorms. Waves calm to 2 feet. .SATURDAY...East winds 10 to 20 knots backing northeast by mid afternoon. Showers likely and a slight chance of thunderstorms. Waves building to 2 to 4 feet. .SATURDAY NIGHT...North winds 5 to 15 knots backing northwest after midnight. A chance of showers. Waves subsiding to calm to 2 feet. .SUNDAY...West winds 5 to 15 knots. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .MONDAY...Southwest winds 5 to 15 knots becoming south 10 to 20 knots. A chance of showers and thunderstorms. Waves building to 1 to 3 feet. .TUESDAY...Southwest winds 10 to 20 knots veering northwest. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. $$ LSZ264-210415- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 405 PM EDT Thu Jun 20 2024 .LATE THIS AFTERNOON...East winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...East winds less than 10 knots. Waves calm to 2 feet. .FRIDAY...East winds less than 10 knots veering south late. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...South winds less than 10 knots backing southeast after midnight, then becoming east 5 to 15 knots late. A slight chance of showers. Waves calm to 2 feet. .SATURDAY...East winds 5 to 15 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. .SATURDAY NIGHT...Northeast winds 5 to 15 knots backing north after midnight. A chance of showers. Waves calm to 2 feet. .SUNDAY...Northwest winds 5 to 15 knots backing west by mid afternoon. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots backing west after midnight. Waves subsiding to calm to 2 feet. .MONDAY...West winds 5 to 15 knots becoming south 10 to 20 knots. A chance of showers and thunderstorms. Waves building to 1 to 3 feet. .TUESDAY...Southwest winds 10 to 20 knots veering northwest. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. $$ LSZ265-210415- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 405 PM EDT Thu Jun 20 2024 .LATE THIS AFTERNOON...Northeast winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...East winds 5 to 15 knots diminishing to less than 10 knots after midnight, then backing northeast late. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots veering southeast late. A slight chance of showers. Waves calm to 2 feet. .FRIDAY NIGHT...Southeast winds 5 to 15 knots backing east late. A chance of showers. A slight chance of thunderstorms after midnight. Waves calm to 2 feet. .SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. Showers likely and a slight chance of thunderstorms. Waves calm to 2 feet. .SATURDAY NIGHT...North winds 10 to 20 knots backing northwest after midnight. A chance of showers. Waves calm to 2 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves calm to 2 feet. .SUNDAY NIGHT...West winds 10 to 20 knots. Waves calm to 2 feet. .MONDAY...West winds 10 to 20 knots backing south. A chance of showers and thunderstorms. Waves calm to 2 feet. .TUESDAY...West winds 15 to 25 knots becoming northwest 10 to 20 knots. A chance of showers and thunderstorms. Waves calm to 2 feet. $$ LSZ266-210415- 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- 405 PM EDT Thu Jun 20 2024 .LATE THIS AFTERNOON...North winds 5 to 15 knots. Waves calm to 2 feet. .TONIGHT...North winds 5 to 15 knots. Waves calm to 2 feet. .FRIDAY...North winds 5 to 15 knots backing northwest late. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...South winds 5 to 15 knots backing east after midnight. A chance of showers. A slight chance of thunderstorms after midnight. Waves calm to 2 feet. .SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. Showers likely and a slight chance of thunderstorms. Waves calm to 2 feet. .SATURDAY NIGHT...Northeast winds 10 to 20 knots backing north after midnight. A chance of showers. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .MONDAY...West winds 10 to 20 knots backing south. A chance of showers. Waves building to 1 to 3 feet. .TUESDAY...Southwest winds 10 to 20 knots veering northwest. A chance of showers. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. $$ LSZ267-210415- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 405 PM EDT Thu Jun 20 2024 .LATE THIS AFTERNOON...North winds 10 to 20 knots. Waves calm to 2 feet. .TONIGHT...Northwest winds 5 to 15 knots veering north late. Waves calm to 2 feet. .FRIDAY...North winds 5 to 15 knots backing northwest in the afternoon. A slight chance of showers by mid afternoon. Waves calm to 2 feet. .FRIDAY NIGHT...Northwest winds 5 to 15 knots veering northeast late. A chance of showers. Waves calm to 2 feet. .SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. Showers. A slight chance of thunderstorms by mid afternoon. Waves calm to 2 feet. .SATURDAY NIGHT...East winds 10 to 20 knots backing north after midnight. Showers likely through midnight. A chance of showers after midnight. Waves building to 1 to 3 feet. .SUNDAY...Northwest winds 10 to 20 knots. A chance of showers. Waves 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots. Waves subsiding to calm to 2 feet. .MONDAY...West winds 10 to 20 knots backing south. A chance of showers. Waves calm to 2 feet. .TUESDAY...South winds 10 to 20 knots veering west. A chance of showers. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. $$ LSZ261-210415- MAFOR 2021/ Superior West 11110 14100 12200 11100. A chance of showers Friday afternoon. Waves 1 foot or less. Superior North Central 11200 11100 11200 11300 12200 12300. Waves 1 foot or less. Superior South Central 15100 11100 11200. Waves 1 foot or less. Superior East 12810 14800 12700. Waves 1 foot or less. $$ Rolfson Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes