Atmospheric River Impacts Northwest into Northern California

A plume of consistent moisture will pummel the Pacific Northwest and Northern California today and later this weekend, bringing heavier rain and mountain snow to these regions. 

Locally heavy rain and mountain snow is falling across the Cascades of Washington and Oregon and this will work its way down into Northern California later today. Roads will be difficult to travel on due to ponding on roadways and snow up in the mountains. 

One to 2 inches of rain are expected in the Willamette Valley, southern Puget Lowlands, the Blue Mountains, and the Klamath Mountains of northern California, with lesser totals amongst the eastern slopes and Columbia Plateau. Ahead of the coastal ranges, 1 to 4 inches of rain are likely, with higher totals leaning for the central Oregon coast. Amongst the Cascades and coastal ranges, totals of 4 to 7 inches or higher of liquid-equivalent precipitation may occur.

Expect 4 to 8 inches of snow in the northern Rocky mid-elevations, central Rockies, most of the Blue Mountains, and the mid-elevations of the Olympics and Cascades. Eight inches up to 2 feet will pack onto the higher elevations of the Olympics and Cascades and along most ridges of the northern Rockies. However, at the peaks of Washington's Cascades, the Olympics, and north-central Rockies, snow accumulations will stack higher than two feet, with the peaks of the North Cascades breaking in at over 4 feet!

Currently, Flood Watches are posted for portions of western Washington and western Oregon. Winter Storm Warnings and Winter Weather Advisories are in effect across the Cascades and northern Rockies.

In addition to the rain and mountain snow, the winds will be howling across the Northwest, Great Basin and along the Rocky Mountain Front Range. Wind gusts will generally reach 40 to 60 mph, with locally higher wind gusts possible over the mountains and higher elevations.

High Wind Watches/Warnings and Wind Advisories are scattered from the Northwest to the High Plains.

Another event is likely later Saturday into Sunday across Northern California and western Oregon bringing more rain and mountain snow. 

Be sure to download the WeatherBug app to stay up to date on the latest on this changing weather. It’s never too early to have a supply kit packed in case of inclement weather. A simple kit including a weather radio, water, blankets, batteries, and non-perishable food items will go a long way in the event of a power outage.