The ridge of high pressure that has kept temperatures well above average throughout much of Montana is begin to flatten out. A trough works in Monday night into Tuesday bringing with it much cooler air. A backdoor cold front moves south Monday night dropping temperatures about 20-30 degrees and changing any rain showers to snow. The ridge gradually builds back in during the rest of the week with a return to seasonable temperatures.
Sunday night: Increasing clouds. A spot shower possible. Overnight lows in the low to mid 30s.
Monday: Partly cloudy, followed by scattered showers and thunderstorms during the afternoon. Storms could be accompanied by heavy downpours and gusty winds. High temperatures in the upper 60s. Rain showers continue overnight as the cold front moves south, rain will begin changing to snow just before dawn. Overnight lows in the upper 20s.
Tuesday: Cooler with snow showers tapering during the afternoon. High temperatures in the low to mid 40s. A slushy coating to an inch of accumulation is possible in Great Falls, with a few inches possible in the Little Belts and the Big Belts. Overnight lows in the upper 10s and low 20s.
Wednesday: Mostly sunny. High temperatures in the upper 50s. Overnight low temperatures in the mid 30s.
Thursday: Scattered showers. Otherwise, partly cloudy. High temperatures in the upper 40s to around 50. Overnight low temperatures in the lower 30s.
Friday: Mixture of sunshine and clouds. High temperatures in the lower 50s. Overnight low temperatures in the low 30s.
Saturday: Mostly sunny. High temperatures in the upper 50s. Overnight low temperatures in the lower 30s.
Sunday: Mostly sunny. High temperatures in the mid 60s.