Great Lakes Forecast
Issued by NWS
Issued by NWS
564 FZUS63 KMQT 181346 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 946 AM EDT Tue Jun 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 weakening 29.4 inch low over northeastern South Dakota this morning continues tracking into northern Ontario today, eventually reaching James Bay at 29.6 inches Wednesday morning as it pulls a 29.7 inch trough over Lake Superior the rest of today through this evening. As the low lifts northeast, high pressure to 30.4 inches builds over Lake Superior for Thursday and Friday. By Friday night, the high weakens to 30.2 inches and slides east. Low pressure of at least 29.7 inches lifts off of the Colorado Rockies Friday night and brings troughing of around 29.6 inches over Lake Superior Saturday as the low moves into Canada. The troughing over Lake Superior deepens to at least 29.5 inches by Sunday as the low strengthens over northern Ontario. LSZ162-182200- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 946 AM EDT Tue Jun 18 2024 /846 AM CDT Tue Jun 18 2024/ .REST OF TODAY...Northeast winds 10 to 20 knots veering south late. A chance of showers and thunderstorms by mid afternoon. Waves 1 to 3 feet building to 2 to 4 feet, then subsiding to 1 to 3 feet. .TONIGHT...South winds 10 to 20 knots becoming southwest 15 to 25 knots after midnight, then veering west late. Showers and thunderstorms likely through midnight, then a chance of showers and thunderstorms after midnight. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet. .WEDNESDAY...West winds 15 to 25 knots becoming southwest 10 to 20 knots late. A slight chance of showers and thunderstorms through early afternoon. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...West winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .THURSDAY...Northeast winds 5 to 15 knots increasing to 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to 2 feet. .FRIDAY...Northeast winds 10 to 20 knots. Showers likely and a chance of thunderstorms. Waves building to 1 to 3 feet. .SATURDAY...Northeast winds 15 to 25 knots diminishing to 10 to 20 knots. Showers likely. A chance of thunderstorms. A chance of showers. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. $$ LSZ263-182200- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 946 AM EDT Tue Jun 18 2024 .REST OF TODAY...South winds 10 to 20 knots increasing to 15 to 25 knots late. A slight chance of showers and thunderstorms by mid afternoon. Waves 1 to 3 feet. .TONIGHT...South winds 10 to 20 knots veering southwest after midnight, then increasing to 15 to 25 knots late. Showers likely through midnight. A chance of thunderstorms. A chance of showers after midnight. Waves building to 3 to 5 feet occasionally to 7 feet. .WEDNESDAY...West winds 10 to 20 knots. A slight chance of showers and thunderstorms through early afternoon. Waves subsiding to 1 to 3 feet. .WEDNESDAY NIGHT...West winds 5 to 15 knots veering north after midnight. Waves subsiding to calm to 2 feet. .THURSDAY...Northeast winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY NIGHT...East winds less than 10 knots. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots. A chance of showers. A chance of thunderstorms. Showers likely. Waves calm to 2 feet. .SATURDAY...East winds 10 to 20 knots. Showers likely. A chance of thunderstorms. A chance of showers. Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet. $$ LSZ264-182200- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 946 AM EDT Tue Jun 18 2024 .REST OF TODAY...South winds 10 to 20 knots increasing to 15 to 25 knots late. Patchy fog by late morning. A slight chance of showers and thunderstorms by mid afternoon. Waves 1 to 3 feet building to 3 to 5 feet occasionally to 7 feet. .TONIGHT...South winds 10 to 20 knots becoming southwest 15 to 25 knots late. A chance of showers and thunderstorms. Waves 3 to 5 feet occasionally to 7 feet. .WEDNESDAY...West winds 10 to 20 knots. A slight chance of showers and thunderstorms through early afternoon. Waves subsiding to 1 to 3 feet. .WEDNESDAY NIGHT...West winds 5 to 15 knots veering north after midnight. Waves subsiding to calm to 2 feet. .THURSDAY...North winds 5 to 15 knots veering northeast by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Southwest winds less than 10 knots backing southeast after midnight. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .SATURDAY...East winds 10 to 20 knots. Showers likely. A chance of thunderstorms. A chance of showers. Waves building to 2 to 4 feet. $$ LSZ265-182200- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 946 AM EDT Tue Jun 18 2024 .REST OF TODAY...South winds 15 to 25 knots backing southeast in the afternoon, then veering south late. Waves 1 to 3 feet building to 2 to 4 feet. .TONIGHT...South winds 15 to 25 knots veering southwest late. A chance of showers and thunderstorms. Waves building to 3 to 5 feet occasionally to 7 feet, then subsiding to 1 to 3 feet. .WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots late. A chance of showers and thunderstorms. Waves subsiding to calm to 2 feet. .WEDNESDAY NIGHT...West winds 5 to 15 knots veering northwest after midnight. A slight chance of showers through midnight. Waves calm to 2 feet. .THURSDAY...North winds 5 to 15 knots veering northeast by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...South winds 5 to 15 knots becoming southeast less than 10 knots after midnight. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots. A chance of showers, then showers likely. Waves calm to 2 feet. .SATURDAY...East winds 10 to 20 knots veering southeast. Showers likely and a chance of thunderstorms. Waves building to 1 to 3 feet. $$ LSZ266-182200- 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- 946 AM EDT Tue Jun 18 2024 .REST OF TODAY...South winds 15 to 25 knots increasing to 20 to 30 knots in the afternoon. Waves 1 to 3 feet building to 3 to 6 feet occasionally to 8 feet. .TONIGHT...South winds 20 to 30 knots diminishing to 15 to 25 knots after midnight. A chance of showers and thunderstorms. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to 20 knots late. A chance of showers and a slight chance of thunderstorms. Waves subsiding to 2 to 4 feet. .WEDNESDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. A slight chance of showers. Waves subsiding to calm to 2 feet. .THURSDAY...North winds 5 to 15 knots. Waves calm to 2 feet. .THURSDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .FRIDAY...East winds 5 to 15 knots. A chance of showers. Waves calm to 2 feet. .SATURDAY...East winds 10 to 20 knots becoming southeast 15 to 25 knots. Showers likely. Waves building to 2 to 4 feet. $$ LSZ267-182200- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 946 AM EDT Tue Jun 18 2024 .REST OF TODAY...South winds 15 to 25 knots increasing to 20 to 30 knots late. Waves 1 to 3 feet building to 3 to 5 feet occasionally to 7 feet. .TONIGHT...South winds 15 to 25 knots. A chance of showers and thunderstorms. Waves subsiding to 2 to 4 feet. .WEDNESDAY...Southwest winds 10 to 20 knots veering west in the afternoon. A chance of showers and thunderstorms. Waves subsiding to 1 to 3 feet. .WEDNESDAY NIGHT...West winds 5 to 15 knots veering northwest after midnight. A slight chance of thunderstorms through midnight. A chance of showers. Waves subsiding to calm to 2 feet. .THURSDAY...North winds 5 to 15 knots becoming northwest 10 to 20 knots by mid afternoon. Waves calm to 2 feet. .THURSDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .FRIDAY...Northeast winds 5 to 15 knots veering east. A chance of showers. Waves calm to 2 feet. .SATURDAY...Southeast winds 10 to 20 knots. Showers likely and a chance of thunderstorms. Waves building to 1 to 3 feet. $$ LSZ261-182200- MAFOR 1815/ Superior West 12320 11420 11429 11436 11530 11630 11620. Waves 2 to 3 feet this afternoon. Waves 2 to 4 feet building to 3 to 5 feet tonight. Waves 3 to 5 feet Wednesday morning. Superior North Central 11420 12330 11420 11426 11420 11530 11520. A chance of thunderstorms tonight. Waves 2 to 4 feet building to 3 to 5 feet this afternoon. Waves 3 to 5 feet tonight and Wednesday morning. Superior South Central 11420 11330 13430 11420 11520 11620. A chance of showers and thunderstorms tonight. A chance of showers Wednesday morning. Waves 2 to 4 feet this afternoon. Waves 3 to 5 feet subsiding to 2 to 4 feet tonight. Waves 1 to 3 feet Wednesday morning. Superior East 11420 14430 11430 11420 11520. A chance of showers and thunderstorms overnight and Wednesday morning. Waves 2 to 4 feet building to 3 to 5 feet this afternoon. Waves 3 to 6 feet tonight and Wednesday morning. $$ TAP Experimental modernized open lake forecast is available online at weather.gov/mqt/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes