Great Lakes Forecast
Issued by NWS
Issued by NWS
224 FZUS63 KMQT 210202 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 1001 PM EDT Mon Jul 20 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... A low pressure will track into Ontario and deepen to 29.4 inches tonight with a 29.5 inch trough over Lake Superior. The low will then push east into Quebec and retrograde to northern Quebec for midweek. Meanwhile a 30.1 inch ridge descends southeast over the Midwest Tuesday through Wednesday night, moving into the Ohio River Valley on Thursday with weak ridging of 29.9 inches extending back northwest over Lake Superior. Another high pressure of 30.1 inches will move south through Ontario on Friday building to 30.2 inches over eastern Ontario by Saturday morning, extending a 30.1 inch ridge over Lake Superior. LSZ162-210800- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1001 PM EDT Mon Jul 20 2026 /901 PM CDT Mon Jul 20 2026/ .REST OF TONIGHT...West winds 15 to 25 knots increasing to 20 to 30 knots after midnight. Patchy smoke by midnight. A slight chance of thunderstorms by midnight. A slight chance of showers. Waves 1 to 3 feet. .TUESDAY...Northwest winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon, then veering north late. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. .TUESDAY NIGHT...North winds 10 to 20 knots backing northwest after midnight. Waves calm to 2 feet. .WEDNESDAY...Northwest winds 5 to 15 knots becoming southwest 10 to 20 knots by mid afternoon. Waves building to 1 to 3 feet. .WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .THURSDAY...Southwest winds 10 to 20 knots. Waves building to 1 to 3 feet. .THURSDAY NIGHT...Southwest winds 5 to 15 knots. Waves subsiding to calm to 2 feet. .FRIDAY...Southwest winds 10 to 20 knots. A chance of showers. Waves building to 1 to 3 feet. .SATURDAY...Southwest winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves building to 2 to 4 feet, then subsiding to calm to 2 feet. $$ LSZ263-210800- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 1001 PM EDT Mon Jul 20 2026 .REST OF TONIGHT...West winds 15 to 25 knots. A chance of showers and a slight chance of thunderstorms. Waves 3 to 5 feet occasionally to 7 feet. .TUESDAY...Northwest winds 20 to 30 knots veering north late. Waves subsiding to 2 to 4 feet. .TUESDAY NIGHT...North winds 15 to 25 knots becoming northwest 10 to 20 knots after midnight. Patchy smoke through midnight. Waves subsiding to 1 to 3 feet. .WEDNESDAY...Northwest winds 10 to 20 knots backing southwest by mid afternoon. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .WEDNESDAY NIGHT...Southwest winds 10 to 20 knots veering west after midnight. Waves subsiding to calm to 2 feet. .THURSDAY...Southwest winds 15 to 25 knots. Waves building to 2 to 4 feet. .THURSDAY NIGHT...Southwest winds 10 to 20 knots. A chance of showers and thunderstorms. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .FRIDAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .SATURDAY...Southwest winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves subsiding to 1 to 3 feet. $$ LSZ264-210800- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 1001 PM EDT Mon Jul 20 2026 .REST OF TONIGHT...West winds 15 to 25 knots. A slight chance of showers. A slight chance of thunderstorms after midnight. Waves 3 to 5 feet occasionally to 7 feet. .TUESDAY...Northwest winds 20 to 30 knots increasing to 30 knots with a few gale force gusts to 35 knots possible in the afternoon. A slight chance of showers 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. .TUESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to 15 to 25 knots after midnight. Waves subsiding to 2 to 4 feet. .WEDNESDAY...Northwest winds 10 to 20 knots backing west by mid afternoon. Waves subsiding to 1 to 3 feet. .WEDNESDAY NIGHT...West winds 10 to 20 knots. Waves 1 to 3 feet. .THURSDAY...Southwest winds 10 to 20 knots. Waves building to 2 to 4 feet. .THURSDAY NIGHT...Southwest winds 5 to 15 knots increasing to 10 to 20 knots after midnight. A chance of showers and thunderstorms. Waves subsiding to calm to 2 feet. .FRIDAY...Southwest winds 10 to 20 knots increasing to 15 to 25 knots. Waves building to 1 to 3 feet, then subsiding to calm to 2 feet. .SATURDAY...Southwest winds 15 to 25 knots diminishing to 10 to 20 knots. A chance of showers. Waves subsiding to 1 to 3 feet. $$ LSZ265-210800- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 1001 PM EDT Mon Jul 20 2026 ...GALE WARNING IN EFFECT FROM 8 AM EDT TUESDAY THROUGH LATE TUESDAY NIGHT... .REST OF TONIGHT...West winds 20 to 30 knots increasing to gales to 35 knots late. A slight chance of showers. A slight chance of thunderstorms after midnight. Waves 2 to 4 feet building to 3 to 5 feet occasionally to 7 feet. .TUESDAY...Northwest gales to 40 knots. A slight chance of showers through early afternoon. Waves building to 7 to 10 feet occasionally to 13 feet. .TUESDAY NIGHT...Northwest gales to 40 knots diminishing to 20 to 30 knots late. Patchy smoke after midnight. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .WEDNESDAY...Northwest winds 20 to 30 knots becoming west 15 to 25 knots by mid afternoon. Waves subsiding to 1 to 3 feet. .WEDNESDAY NIGHT...West winds 15 to 25 knots. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .THURSDAY...West winds 10 to 20 knots becoming southwest 5 to 15 knots by mid afternoon. Waves subsiding to calm to 2 feet. .THURSDAY NIGHT...Southwest winds 10 to 20 knots increasing to 15 to 25 knots after midnight. Waves calm to 2 feet. .FRIDAY...Southwest winds 10 to 20 knots. Waves building to 1 to 3 feet. .SATURDAY...Southwest winds 15 to 25 knots veering west. A chance of showers. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. $$ LSZ266-210800- 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 PM EDT Mon Jul 20 2026 ...GALE WARNING IN EFFECT FROM 8 AM EDT TUESDAY THROUGH LATE TUESDAY NIGHT... .REST OF TONIGHT...Southwest winds 15 to 25 knots veering west after midnight, then increasing to 20 to 30 knots late. A slight chance of thunderstorms by midnight. A chance of showers. Some thunderstorms may be severe. Waves 3 to 6 feet occasionally to 8 feet. .TUESDAY...Northwest gales to 40 knots. A slight chance of showers through early afternoon. Waves building to 8 to 12 feet occasionally to 15 feet. .TUESDAY NIGHT...Northwest gales to 40 knots diminishing to 20 to 30 knots late. A slight chance of showers through midnight. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .WEDNESDAY...Northwest winds 20 to 30 knots becoming west 15 to 25 knots by mid afternoon. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .WEDNESDAY NIGHT...West winds 15 to 25 knots. Waves subsiding to 1 to 3 feet. .THURSDAY...West winds 10 to 20 knots backing southwest by mid afternoon. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. .THURSDAY NIGHT...South winds 5 to 15 knots becoming southwest 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet. .FRIDAY...South winds 5 to 15 knots increasing to 10 to 20 knots. Waves building to 2 to 4 feet. .SATURDAY...South winds 10 to 20 knots veering southwest. A chance of showers, then showers likely. Waves subsiding to 1 to 3 feet. $$ LSZ267-210800- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 1001 PM EDT Mon Jul 20 2026 ...GALE WARNING IN EFFECT FROM 8 AM EDT TUESDAY THROUGH LATE TUESDAY NIGHT... .REST OF TONIGHT...South winds 15 to 25 knots veering west late. A chance of thunderstorms by midnight. A chance of showers. Some thunderstorms may be severe. Waves 2 to 4 feet building to 3 to 5 feet occasionally to 7 feet. .TUESDAY...West winds 20 to 30 knots becoming northwest gales to 40 knots in the afternoon. A chance of showers. Waves building to 8 to 12 feet occasionally to 15 feet. .TUESDAY NIGHT...Northwest gales to 35 knots. A slight chance of showers through midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .WEDNESDAY...Northwest winds 20 to 30 knots backing west by mid afternoon. Waves subsiding to 3 to 6 feet occasionally to 8 feet. .WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to 1 to 3 feet. .THURSDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots by mid afternoon. Waves subsiding to calm to 2 feet. .THURSDAY NIGHT...South winds 5 to 15 knots becoming southwest 10 to 20 knots after midnight. Waves calm to 2 feet. .FRIDAY...Southwest winds 5 to 15 knots becoming south 10 to 20 knots. Waves building to 2 to 4 feet. .SATURDAY...South winds 10 to 20 knots veering southwest. Showers likely. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. $$ LSZ261-210800- MAFOR 2103/ Superior West 12630 14730 11720 11820. Waves 2 to 4 feet subsiding to 1 to 3 feet overnight. Waves 1 to 3 feet Tuesday and Tuesday evening. Superior North Central 11620 11630 12740 13750 11740. A chance of showers overnight. Waves 3 to 6 feet. Superior South Central...GALE WARNING IN EFFECT...11630 12640 12750 12760 11750. A chance of showers late this evening. Waves 2 to 4 feet building to 3 to 5 feet overnight. Waves 5 to 8 feet building to 7 to 10 feet Tuesday. Waves 6 to 10 feet Tuesday evening. Superior East...GALE WARNING IN EFFECT...11520 11620 11630 11740 14750. A chance of showers overnight and Tuesday morning. Waves 3 to 5 feet overnight. Waves 5 to 8 feet building to 7 to 10 feet Tuesday. Waves 6 to 10 feet Tuesday evening. $$ 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