SXUS45 KMSO 191230 RECGPI Recreation Forecast for Flathead Lake National Weather Service Missoula MT 605 AM MDT Thu Mar 19 2026 Note: The experimental wave height forecasts are representative of the mid lake waters and downwind shores. Wave heights may be significantly less on upwind shores. .Today...Mostly cloudy. A 20 percent chance of rain in the afternoon. Highs around 60 . South winds around 15 mph. Waves around 1 foot...locally up to 2 feet. .Tonight...Mostly cloudy. A slight chance of rain in the evening, then a chance of rain after midnight. Lows around 50 . South winds around 15 mph. Chance of rain 30 percent. Waves less than 1 foot. .FRIDAY...Mostly cloudy with a 50 percent chance of rain. Highs around 60 . South winds around 15 mph. Waves around 1 foot... locally up to 2 feet. .FRIDAY NIGHT...Breezy. Rain likely. Lows in the upper 40s. Southwest winds 15 to 20 mph. Chance of rain 70 percent. Waves around 1 foot...locally up to 2 feet. .SATURDAY...Breezy. Cloudy with rain likely in the morning, then mostly sunny with a chance of rain in the afternoon. Highs in the mid 50s. Southwest winds 15 to 20 mph. Chance of rain 60 percent. Waves around 1 foot...locally up to 2 feet.