Modest atmospheric river heading toward Snohomish County

Published 3:28 pm Monday, December 16, 2024

EVERETT — A modest atmospheric river will hit Snohomish County this week, bringing heavy rains and snow at higher elevations.

Atmospheric rivers are narrow strips of atmosphere carrying large quantities of water vapor from the tropics. When the transported vapor hits land, the river often releases rain or snow.

“It looks like this source of moisture is a little north of Hawaii,” National Weather Service forecaster Dustin Guy said. “The atmospheric river is going to funnel the moisture into the Pacific Northwest this week.”

Tuesday morning has a 90% chance of precipitation, rising to 100% in the evening with accumulation of half an inch of rain possible in the Everett area.

High chances of rain will continue through Thursday.

Looking into next week, “we might be talking about atmospheric rivers through the holidays,” Guy said.

Meteorologists don’t predict any local river flooding from rain this week.

A winter weather advisory in the Cascades, including Index, Darrington and Stevens Pass, was also set to be in effect from 4 a.m. Tuesday to 4 a.m. Wednesday. Forecast show 5 to 10 inches of snow possible above 2,500 feet and wind gusts as high as 35 mph.

Eliza Aronson: 425-339-3434; eliza.aronson@heraldnet.com; X: @ElizaAronson. Eliza’s stories are supported by the Herald’s Environmental and Climate Reporting Fund.