Very warm atmospheric river aims at PNW through Wednesday

PORTLAND, Ore. (KOIN) -- A flood watch remains in effect through Wednesday everywhere west of the Cascades. Small stream flooding is possible, as the rainfall picks up.

Rain continues Sunday morning and will be heavy at times before backing off to scattered showers by the afternoon. Expect blustery conditions at times as the front moves through the region.

Rainfall picked up across the Portland metro in the early hours of Sunday as another in a series of Pacific frontal systems takes aim at the region.

Snow changed to mostly rain Sunday morning across the Cascade passes as snow levels rose to nearly 6000 feet overnight. All that fresh powder on the slopes is likely to melt substantially over the next 72 hours as yet another very warm atmospheric river develops off the Pacific coast and will be aimed directly at the Pacific Northwest through Wednesday.

In fact, by Tuesday evening we may see as much as 2-3 inches of rain in the Willamette Valley and up to 4-6 inches at some locations along the Oregon coast and in the Coast Range.

Snowfall levels finally return to at or below pass levels later in the week as the upper-level flow turns more northwesterly. Keep your rain jacket and your boots handy. You are going to need both of them, for the next few days.

Stay with KOIN 6 News for all the latest weather information.