The largest snowstorm of season is currently occurring in progress for the higher Cascades, with a cold front interacting with subtropical moisture overnight and turning the rain heavy until daybreak Thursday. The main rain band will lift slightly north of Portland Thursday night, then swing southward into northern Oregon Friday midday and afternoon, resulting in 3-4” of rain total by the time the rain tapers off at sunrise Saturday. This is expected to cause local spots of flooding and significant rises in rives due to rising rives. An atmospheric river is aimed at southern Washington and extreme northern Oregon, and remains in place until late Friday night. Forecasters predict that the biggest snowstorm this season will bring up to 20” at pass elevations.