SXUS45 KMSO 211230 RECGPI Recreation Forecast for Flathead Lake National Weather Service Missoula MT 605 AM MDT Sat Mar 21 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...Breezy. Cloudy with rain early in the morning, then mostly cloudy with a chance of rain in the late morning and early afternoon. Mostly sunny late in the afternoon. Highs in the lower 50s. South winds around 15 mph shifting to the southwest 15 to 25 mph with gusts to around 30 mph in the afternoon. Chance of rain 90 percent. Waves around 1 foot...locally up to 2 feet. .Tonight...Mostly clear. Lows in the upper 30s. Southwest winds around 15 mph. Gusts up to 30 mph in the evening. Waves around 1 foot...locally up to 2 feet. .SUNDAY...Sunny. Highs around 50 . South winds around 15 mph. Waves around 1 foot...locally up to 2 feet. .SUNDAY NIGHT...Partly cloudy in the evening then becoming mostly cloudy. Lows in the mid 30s. Variable winds up to 10 mph. Waves around 1 foot...locally up to 2 feet. .MONDAY...Partly sunny. Highs in the mid 50s. Variable winds up to 10 mph. Waves less than 1 foot.