FZUS61 KBUF 222003 GLFSL Forecast for the Saint Lawrence River including the Thousand Islands Region National Weather Service Buffalo NY 403 PM EDT Sat Aug 22 2026 SLZ022-024-230300- Saint Lawrence River from Cape Vincent to Saint Regis 403 PM EDT Sat Aug 22 2026 .TONIGHT...Southeast winds 10 knots or less increasing to 10 to 15 knots. A chance of showers and thunderstorms after midnight. Showers likely with a chance of thunderstorms late. .SUNDAY...Southeast winds 10 to 15 knots becoming southwest. Showers with a chance of thunderstorms. .SUNDAY NIGHT...Southwest winds 10 to 15 knots. A chance of showers in the evening, then showers overnight. .MONDAY...Southwest winds 5 to 15 knots. Showers in the morning, then showers with a chance of thunderstorms in the afternoon. .MONDAY NIGHT...Southwest winds 5 to 10 knots. Showers likely in the evening, then a chance of showers overnight. .TUESDAY...West winds 5 to 10 knots becoming light and variable. A chance of showers and thunderstorms. .WEDNESDAY...Southwest winds less than 10 knots becoming south. Partly cloudy. .THURSDAY...South winds 10 knots or less. A chance of showers during the day, then showers likely Thursday night. Winds and waves higher in and near thunderstorms. $$