Atmospheric river unfolds: rain snow invades Northwest

After a bit of a dry spell, the Pacific Northwest and northern California will be bombarded by heavy rain and mountain snow through the weekend.

A stream of Pacific moisture will roll ashore later tonight and Friday, producing waves of heavy rain from the San Francisco Bay area northward to Seattle through the weekend. The WeatherRadar shows the waves of rain developing over the Pacific, extending from Hawaii. A strong system is producing severe storms, including gusty winds and water spouts across the Aloha State.

In the Cascades and Sierra Nevada, heavy snow will fall in the higher elevations. The Cascades could receive more than 2 feet of snow while a rain-snow mix will produce lower accumulations in the Sierra. The snow will move into the Intermountain West and the northern Rockies this weekend.

Called an atmospheric rivers, these Pacific systems can produce rain and mountain snow for days, bringing much needed precipitation. They can also produce high winds and cause rivers and low-lying areas to flood.

It has been a quiet and mostly dry start to 2025 across the West Coast. Winter is the wettest season but drought has expanded across the Northwest. Seattle is running 3.50 inches behind in the rainfall department this month.

Weather and Radar meteorologists will be tracking the latest on winter system. The Weather News section can provided the latest news and details.