511 FZUS63 KMQT 180800 GLFLS Open Lake Forecast for Lake Superior National Weather Service Marquette MI 400 AM EDT Sat Apr 18 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 of 29.3 inches over northern Ontario lifts into James Bay later this morning. Behind it, ridging builds over Lake Superior, strengthening to about 30.3 inches Sunday night into Monday morning. This ridging gives way to 29.8 inch troughing Monday night into Tuesday morning as a weakening low swings from the Hudson Bay shoreline of far northern Ontario towards northern Quebec. High pressure ridging builds back to 30.2 inches over Lake Superior by Tuesday night. The high shifts east on Wednesday as a 29.2 inch low pressure develops over the Northern Plains. LSZ162-182000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 400 AM EDT Sat Apr 18 2026 /300 AM CDT Sat Apr 18 2026/ .EARLY THIS MORNING...West winds 20 to 30 knots. Waves 3 to 6 feet occasionally to 8 feet. .TODAY...West winds to 30 knots with a few gale force gusts to 35 knots possible. A slight chance of snow showers. A slight chance of rain showers by mid afternoon. Waves building to 5 to 8 feet occasionally to 10 feet. .TONIGHT...West winds 20 to 30 knots becoming northwest 15 to 25 knots after midnight. Waves subsiding to 2 to 4 feet. .SUNDAY...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots in the afternoon. Waves subsiding to calm to 2 feet. .SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after midnight. Waves calm to 2 feet. .MONDAY...South winds 10 to 20 knots increasing to 15 to 25 knots by mid afternoon. Waves building to 2 to 4 feet. .MONDAY NIGHT...Southwest winds 15 to 25 knots veering west after midnight. Waves subsiding to 1 to 3 feet. .TUESDAY...West winds 5 to 15 knots veering northeast. Waves subsiding to calm to 2 feet. .WEDNESDAY...East winds 5 to 15 knots increasing to 10 to 20 knots. A chance of rain showers. Waves building to 3 to 5 feet occasionally to 7 feet. $$ LSZ263-182000- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- 400 AM EDT Sat Apr 18 2026 ...GALE WARNING IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... .EARLY THIS MORNING...West winds 15 to 25 knots. Waves 4 to 7 feet occasionally to 9 feet. .TODAY...West winds 20 to 30 knots increasing to gales to 35 knots in the afternoon. A slight chance of snow showers. Waves building to 8 to 12 feet occasionally to 15 feet. .TONIGHT...West winds 20 to 30 knots veering northwest after midnight, then diminishing to 15 to 25 knots late. Flurries through midnight. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .SUNDAY...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots in the afternoon. Waves subsiding to 1 to 3 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Southwest winds 15 to 25 knots backing south by mid afternoon. Waves building to 3 to 5 feet occasionally to 7 feet. .MONDAY NIGHT...Southwest winds 20 to 30 knots becoming west 15 to 25 knots after midnight. Waves building to 3 to 6 feet occasionally to 8 feet. .TUESDAY...West winds 10 to 20 knots becoming east less than 10 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...East winds 5 to 15 knots becoming southeast 15 to 25 knots. A chance of rain showers. Waves building to 3 to 5 feet occasionally to 7 feet. $$ LSZ264-182000- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- 400 AM EDT Sat Apr 18 2026 ...GALE WARNING IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... .EARLY THIS MORNING...Northwest winds 20 to 30 knots. Waves 4 to 7 feet occasionally to 9 feet. .TODAY...West winds 20 to 30 knots increasing to gales to 35 knots in the afternoon. A slight chance of snow showers. Waves building to 9 to 12 feet occasionally to 15 feet. .TONIGHT...Northwest gales to 35 knots diminishing to 20 to 30 knots after midnight. A chance of snow showers through midnight. Waves subsiding to 5 to 8 feet occasionally to 10 feet. .SUNDAY...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots late. Waves subsiding to 2 to 4 feet. .SUNDAY NIGHT...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Southwest winds 10 to 20 knots becoming south 15 to 25 knots by mid afternoon. Waves building to 3 to 5 feet occasionally to 7 feet. .MONDAY NIGHT...South winds 20 to 30 knots becoming west 15 to 25 knots after midnight. Waves building to 4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. .TUESDAY...West winds 10 to 20 knots becoming north less than 10 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...Southeast winds 5 to 15 knots increasing to 15 to 25 knots. Waves building to 3 to 6 feet occasionally to 8 feet. $$ LSZ265-182000- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- 400 AM EDT Sat Apr 18 2026 ...GALE WARNING IN EFFECT FROM 1 PM EDT THIS AFTERNOON THROUGH THIS EVENING... .EARLY THIS MORNING...West gales to 35 knots. Waves 4 to 7 feet occasionally to 9 feet. .TODAY...West gales to 40 knots. A slight chance of snow showers. Waves building to 6 to 9 feet occasionally to 11 feet. .TONIGHT...West gales to 40 knots becoming northwest gales to 35 knots after midnight, then diminishing to 20 to 30 knots late. A chance of snow showers. Waves subsiding to 4 to 7 feet occasionally to 9 feet. .SUNDAY...Northwest winds 20 to 30 knots. Waves subsiding to 3 to 5 feet occasionally to 7 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to calm to 2 feet. .MONDAY...Southwest winds 10 to 20 knots becoming southeast 15 to 25 knots by mid afternoon. Waves building to 2 to 4 feet. .MONDAY NIGHT...South gales to 35 knots veering southwest after midnight. Waves building to 3 to 6 feet occasionally to 8 feet, then subsiding to 2 to 4 feet. .TUESDAY...Northwest winds 10 to 20 knots diminishing to 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...East winds 5 to 15 knots becoming southeast 15 to 25 knots. Waves building to 3 to 6 feet occasionally to 8 feet. $$ LSZ266-182000- 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- 400 AM EDT Sat Apr 18 2026 ...GALE WARNING IN EFFECT FROM 1 PM EDT THIS AFTERNOON THROUGH THIS EVENING... .EARLY THIS MORNING...Northwest gales to 35 knots. A chance of rain showers, possibly mixed with sleet. Waves 5 to 9 feet occasionally to 11 feet. .TODAY...Northwest gales to 35 knots backing west in the afternoon. A slight chance of snow showers. Waves building to 10 to 14 feet occasionally to 18 feet. .TONIGHT...West gales to 35 knots veering northwest after midnight. A chance of snow showers. Waves subsiding to 8 to 11 feet occasionally to 14 feet. .SUNDAY...Northwest winds 20 to 30 knots increasing to gales to 35 knots in the afternoon, then diminishing to 20 to 30 knots late. Waves subsiding to 6 to 9 feet occasionally to 11 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 10 to 20 knots after midnight. Waves subsiding to 2 to 4 feet. .MONDAY...Southwest winds 5 to 15 knots becoming south 20 to 30 knots by mid afternoon. Waves subsiding to calm to 2 feet, then building to 2 to 4 feet. .MONDAY NIGHT...South gales to 40 knots veering southwest after midnight. Waves building to 7 to 10 feet occasionally to 13 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. .TUESDAY...Northwest winds 15 to 25 knots diminishing to 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...East winds 5 to 15 knots becoming southeast 20 to 30 knots. Waves building to 3 to 6 feet occasionally to 8 feet. $$ LSZ267-182000- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 400 AM EDT Sat Apr 18 2026 ...GALE WARNING IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH THIS EVENING... .EARLY THIS MORNING...Northwest winds 20 to 30 knots. Patchy fog. A chance of rain showers. Waves 3 to 6 feet occasionally to 8 feet building to 6 to 9 feet occasionally to 11 feet. .TODAY...Northwest gales to 35 knots becoming west gales to 40 knots in the afternoon. A slight chance of rain showers through early afternoon. A slight chance of snow showers. Waves building to 7 to 11 feet occasionally to 14 feet. .TONIGHT...West gales to 35 knots veering northwest after midnight. A chance of snow showers. Waves subsiding to 8 to 11 feet occasionally to 14 feet. .SUNDAY...Northwest gales to 35 knots. Waves subsiding to 6 to 9 feet occasionally to 11 feet. .SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to 5 to 15 knots after midnight. Waves subsiding to 2 to 4 feet. .MONDAY...West winds 5 to 15 knots becoming south 15 to 25 knots by mid afternoon. Waves subsiding to calm to 2 feet, then building to 1 to 3 feet. .MONDAY NIGHT...South gales to 35 knots veering southwest after midnight. Waves building to 5 to 9 feet occasionally to 11 feet. .TUESDAY...West winds 15 to 25 knots becoming northwest 5 to 15 knots. Waves subsiding to calm to 2 feet. .WEDNESDAY...East winds 5 to 15 knots becoming southeast 15 to 25 knots. Waves building to 2 to 4 feet. $$ LSZ261-181400- MAFOR 1809/ Superior West...GALE WARNING IN EFFECT...11630 11640 12650 12640 11740 11730. Waves 3 to 6 feet building to 6 to 9 feet today. Waves 5 to 9 feet subsiding to 3 to 6 feet tonight. Superior North Central...GALE WARNING IN EFFECT...11740 11640 13650 12750 11740. Waves 5 to 8 feet building to 8 to 12 feet today. Waves 8 to 12 feet subsiding to 6 to 9 feet tonight. Superior South Central...GALE WARNING IN EFFECT...11740 11640 14650 12740. A chance of snow showers tonight. Waves 5 to 8 feet building to 7 to 11 feet today. Waves 7 to 11 feet subsiding to 6 to 9 feet tonight. Superior East...GALE WARNING IN EFFECT...12740 11640 13650 11750 11740. A chance of rain showers early, then a chance of rain showers and light freezing rain this morning. A chance of snow showers tonight. Waves 4 to 7 feet building to 10 to 13 feet today. Waves 10 to 14 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  374 FZUS61 KBUF 180804 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 403 AM EDT Sat Apr 18 2026 For waters beyond five nautical miles of shore on Lake Ontario 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 30.0 inch high will push northeast across the Canadian Maritimes today. Meanwhile, a 29.4 inch low north of Lake Superior this morning will move to James Bay and deepen to 29.0 inches during the day, while pushing a trailing strong cold front across the Lake this afternoon and evening. A 30.4 inch high will then settle southeastward across the Great Lakes Sunday through Monday night, before sliding off the mid-Atlantic coast Tuesday. A 29.4 inch low over lower Hudson Bay Tuesday, will weaken to 29.9 inches by Wednesday, while pushing an attendant weak cold front across the Lake Tuesday night. A 30.2 inch high will then build across the Great Lakes region Wednesday and Thursday. LOZ062-181500- Lake Ontario open waters from the Niagara River to Hamlin Beach- 403 AM EDT Sat Apr 18 2026 .TODAY...Southeast winds 10 to 15 knots becoming southwest 15 to 20 knots. Showers likely early this afternoon. Showers with a chance of thunderstorms late. Some thunderstorms may produce gusty winds late. Waves 1 to 3 feet building to 2 to 4 feet. .TONIGHT...West winds 15 to 20 knots becoming northwest 10 to 15 knots. Rain showers likely. Waves 2 to 4 feet. .SUNDAY...West winds 10 to 15 knots increasing to 15 to 20 knots. A chance of rain and snow showers in the afternoon. Waves 1 to 3 feet building to 2 to 4 feet. .SUNDAY NIGHT...West winds 15 to 20 knots becoming northwest. A chance of rain showers in the evening. Waves 3 to 5 feet. .MONDAY...Northwest winds 15 to 20 knots becoming southwest 5 to 15 knots. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TUESDAY...South winds 15 to 20 knots becoming northwest 10 to 15 knots. A chance of rain showers. Waves 1 to 3 feet building to 2 to 4 feet, then subsiding to 1 to 3 feet. .WEDNESDAY...North winds 10 knots or less. Waves 2 feet or less. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-181500- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 403 AM EDT Sat Apr 18 2026 .TODAY...Southeast winds 15 to 20 knots becoming south. Showers likely late. Waves 1 to 3 feet building to 3 to 5 feet. .TONIGHT...Southwest winds 15 to 20 knots becoming northwest 10 to 15 knots. Rain showers with a chance of thunderstorms early, then rain showers from late evening on. Some thunderstorms may produce gusty winds early. Waves 3 to 5 feet subsiding to 2 to 4 feet. .SUNDAY...West winds 10 to 15 knots increasing to 15 to 20 knots. Rain and snow showers likely in the morning, then a chance of snow showers in the afternoon. Waves 1 to 3 feet building to 3 to 6 feet. .SUNDAY NIGHT...West winds 15 to 20 knots becoming northwest. Waves 3 to 6 feet. .MONDAY...Northwest winds 15 to 20 knots becoming west and diminishing to 5 to 10 knots. Waves 3 to 6 feet subsiding to 1 to 3 feet. .TUESDAY...South winds 10 to 15 knots becoming west. A chance of rain showers. Waves 1 to 3 feet. .WEDNESDAY...North winds 5 to 15 knots. Waves 1 to 3 feet subsiding to 1 foot or less. Winds and waves higher in and near thunderstorms. $$ LOZ061-181500- MAFOR 1809/ ONTARIO WEST 1/2 11310 11410 11420 11426 11626 11620 12710. A chance of thunderstorms this afternoon. Waves 1 to 3 feet building to 2 to 4 feet today. Waves 2 to 4 feet tonight. ONTARIO EAST 1/2 11310 11320 12420 11426 11626 11610 11716. Waves 1 to 3 feet building to 3 to 5 feet today. Waves 3 to 5 feet subsiding to 2 to 4 feet tonight. $$  009 FZUS61 KBUF 180805 GLFSL Forecast for the Saint Lawrence River including the Thousand Islands Region National Weather Service Buffalo NY 404 AM EDT Sat Apr 18 2026 SLZ022-024-181500- Saint Lawrence River from Cape Vincent to Saint Regis 404 AM EDT Sat Apr 18 2026 .TODAY...Southeast winds 5 to 15 knots becoming south 15 to 20 knots. Sunny this morning, then becoming partly sunny. .TONIGHT...South winds 15 to 20 knots becoming west 10 to 15 knots. Rain showers. .SUNDAY...West winds 5 to 15 knots. Rain showers with snow showers likely in the morning, then a chance of rain showers in the afternoon. .SUNDAY NIGHT...West winds 5 to 15 knots becoming northwest. A chance of rain showers in the evening. .MONDAY...Northwest winds 10 knots or less becoming south. Partly cloudy, then becoming mainly clear. .TUESDAY...South winds 5 to 10 knots becoming southwest. A chance of rain showers. .WEDNESDAY...Northwest winds 10 knots or less becoming north. Mostly cloudy, then clearing. $$  306 FZUS63 KMKX 180813 GLFLM OPEN LAKE FORECAST for Lake Michigan National Weather Service Milwaukee/Sullivan WI 313 AM CDT Sat Apr 18 2026 FOR WATERS BEYOND FIVE NAUTICAL MILES OF SHORE ON Lake Michigan. Waves are provided as a range of significant wave heights, which is the average of the highest 1/3 of the wave, along with the average height of the highest 10% of the waves which will occasionally be encountered. .SYNOPSIS... Breezy northwest winds continue to build in behind a cold front, overspreading the lake and achieving 20 to 30 kt gusts through today. Low pressure continues its northeastward track across Ontario Canada and James Bay today, with high pressure systems over the southern Plains and Saskatchewan/Manitoba Canada maintaining a tight pressure gradient and breezy west to northwest winds. High pressure builds its way into the Midwestern US states through Sunday / Monday, with continued northwest wind flow Sunday then light and variable winds into Monday morning as the high makes its closest approach to Lake Michigan. As the high exits east, expecting breezy southerly winds Monday afternoon and night. LMZ261-362-364-366-563-565-567-868-181515- Lake Michigan from Seul Choix Point to Rock Island Passage 5 NM offshore to Mid Lake- Lake Michigan South of a line from Seul Choix Point to the Mackinac Bridge and north of a line from Charlevoix MI to South Fox Island 5 NM offshore- Lake Michigan from Charlevoix to Point Betsie MI 5 NM offshore to Mid Lake- Lake Michigan from Point Betsie to Manistee MI 5 NM offshore to Mid Lake- Lake Michigan from Rock Island Passage to Sturgeon Bay WI- Lake Michigan from Sturgeon Bay to Two Rivers WI 5 NM offshore to Mid Lake- Lake Michigan from Two Rivers to Sheboygan WI 5 NM offshore to Mid Lake- Lake Michigan from Pentwater to Manistee MI 5 NM offshore to Mid Lake- 313 AM CDT Sat Apr 18 2026 SHEBOYGAN WI TO PENTWATER MI NORTH... ...DENSE FOG ADVISORY IN EFFECT UNTIL 4 AM CDT EARLY THIS MORNING... .TODAY...Northwest winds to 30 kt becoming west. Waves 4 to 6 ft occasionally to 8 ft. .TONIGHT...West winds to 30 kt diminishing to 15 to 25 kt. Waves 4 to 6 ft occasionally to 8 ft. .SUNDAY...West winds 15 to 25 kt becoming north. Waves 2 to 4 ft. .SUNDAY NIGHT...North winds 15 to 25 kt diminishing to 10 to 20 kt. Waves 2 to 4 ft. .MONDAY...West winds 10 to 15 kt becoming south 10 to 20 kt. Waves 1 to 2 ft building to 2 to 4 ft. .MONDAY NIGHT...South winds to 30 kt. Waves 5 to 8 ft occasionally to 10 ft. .TUESDAY...Southwest winds to 30 kt diminishing to 10 to 20 kt. Waves 5 to 8 ft occasionally to 10 ft subsiding to 4 to 6 ft occasionally to 8 ft. .WEDNESDAY...Northeast winds 10 to 15 kt diminishing to 5 to 10 kt. Waves 1 to 2 ft. $$ LMZ080-669-671-673-675-777-779-870-872-874-876-878-181515- Lake Michigan from Michigan City IN to St. Joseph MI 5 NM offshore to Mid Lake- Lake Michigan from Sheboygan to Port Washington WI 5 NM offshore to Mid Lake- Lake Michigan from Port Washington to North Point Light WI 5 NM offshore to Mid Lake- Lake Michigan from North Point Light to Wind Point WI 5 NM offshore to Mid Lake- Lake Michigan from Wind Point WI to Winthrop Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5 NM offshore to Mid Lake- Lake Michigan from Wilmette Harbor IL to Michigan City IN 5 NM offshore to Mid Lake- Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid Lake- Lake Michigan from Grand Haven to Whitehall MI 5 NM offshore to Mid Lake- Lake Michigan from Holland to Grand Haven MI 5 NM offshore to Mid Lake- Lake Michigan from South Haven to Holland MI 5 NM offshore to Mid Lake- Lake Michigan from St. Joseph to South Haven MI 5 NM offshore to Mid Lake- 313 AM CDT Sat Apr 18 2026 SHEBOYGAN WI TO PENTWATER MI SOUTH... ...DENSE FOG ADVISORY IN EFFECT UNTIL 4 AM CDT EARLY THIS MORNING... .TODAY...West winds to 30 kt diminishing to 15 to 25 kt. Slight chance of rain showers this morning. Waves 4 to 6 ft occasionally to 8 ft. .TONIGHT...West winds 15 to 25 kt diminishing to 10 to 20 kt. Waves 4 to 6 ft occasionally to 8 ft. .SUNDAY...West winds 10 to 20 kt becoming northwest. Waves 3 to 5 ft. .SUNDAY NIGHT...North winds 10 to 20 kt becoming northeast 10 to 15 kt. Waves 2 to 4 ft. .MONDAY...East winds 5 to 10 kt becoming southeast 10 to 20 kt in the afternoon. Waves 1 to 2 ft building to 2 to 4 ft. .MONDAY NIGHT...Southeast winds 15 to 25 kt becoming south to 30 kt. Waves 4 to 7 ft occasionally to 9 ft. .TUESDAY...South winds to 30 kt diminishing to 10 to 20 kt. Waves 4 to 7 ft occasionally to 9 ft. .WEDNESDAY...Northeast winds 10 to 15 kt diminishing to 5 to 10 kt. Waves 2 to 4 ft. $$ LMZ761-181515- MAFOR 1810/ MICHIGAN NORTH 12740 11640 12630 11730 12630. A chance of rain showers early this morning. Waves 3 to 5 feet today. Waves 3 to 5 feet subsiding to 2 to 4 feet tonight. MICHIGAN SOUTH 11640 11740 14630 11630 11620. A chance of rain showers early this morning. Waves 2 to 4 feet building to 3 to 6 feet today. Waves 3 to 5 feet tonight. $$ Sheppard Experimental modernized open lake forecast is available online at weather.gov/mkx/glftable Graphical marine forecasts are available online at: weather.gov/greatlakes