Western Montana will see an air mass change Friday, an Arctic cold front will pass through our area rapidly dropping temperatures through the day. Timing will see Northwest Montana transitioning from rain to snow during the morning commute, while I-90 South and East will transition during the evening commute. Above 5000’ should be all snow, while snow levels will drop to 4500’ by noon on Friday. This is a fast moving event and snow amounts will range from 3 to 6” in mountain passes to a trace to 2” in the valleys. Precipitation could be briefly intense with frontal passage, accumulation of wet, slushy snow could be fast during this period. Overnight temperatures will drop rapidly into the teens and low 20’s, causing wet surfaces to freeze.