The WeatherRadar shows a line of rainfall stretching from the Hawaiian latitudes. Called the Pineapple Express due to its tropical origin, this train of moisture will bring heavy rain and mountain snow to the Pacific Northwest over the next two days.

Seattle, Spokane and Yakima, Wash., Missoula, Mont., and Portland and Eugene, Ore., residents will need their umbrellas through Wednesday before a late-week sunshine break. Rain and mountain snow are being fed by the Pineapple Express, a well-known atmospheric river that occurs yearly, helping to add to the water reservoirs and snowpack before the warmer, drier season.

The leeward side of the Cascades in Washington, along the Yakima River, has a flood watch due to the heavy rainfall moving through. The heavy downpours could cause excessive runoff into the river, which is already near flood stage.

The higher peaks of the Cascades and into the northern Rockies could see an icy mix to heavy snow. Keep a close eye on the WeatherRadar if you plan on going through the mountain passes through Wednesday night.