As tranquil weather settles over much of the U.S. this week, an intense California rain storm is developing offshore, poised to bombard the state with drenching rain, howling winds and the threat of flooding from midweek onward.
Atmospheric River Takes Aim at California
Meteorologists have been warning of the ferocity of this storm since mid-January, urging that an atmospheric river will aim directly for California and unleash rainfall heavy enough to trigger flooding, mudslides and travel nightmares.
The Northern to Southern California winter storm will organize and strengthen after a separate winter storm pushes onshore over British Columbia Tuesday, spreading showery rain and mountain snow into the Pacific Northwest.
The main event and its narrowly focused yet torrential rain band, characteristic of atmospheric river events, will take shape well offshore over the Pacific before bearing down on the California coastline. Relentless rainfall will shift from a Northern California storm to a Wednesday Southern California storm Thursday as the moisture pipeline pushes inland.
California Rain Storm to Bring Up to 6 Inches
Senior Meteorologist Heather Zehr stated the storm coming to California will significantly snarl travel across vast stretches of the state from Wednesday through Thursday amidst the traversing flood threat.
“A large swath of 2-4 inch rainfall totals is expected over much of Northern California, with embedded zones of 4 to 6 inch or greater amounts focused along coastal ranges facing toward the southwest,” Zehr said. “The San Francisco metro area falls within the broader 2-4 inch outlook, with 1-2 inches likely extending inland near Sacramento."
Storm Warning Meteorologist Joseph Bauer added that rainfall will overspread the San Francisco Bay Area Wednesday into Wednesday night when the heaviest rain is anticipated. Drenching rain will eventually reach Los Angeles and San Diego Thursday as the Northern California storm center drifts southward and peak intensity shifts into Southern California.
“Several inches of rain will fall near the Central California coast compliments of persistent southwesterly winds drawing dense moisture inland, leading to widespread 1-2 inch totals across Southern California,” Zehr said.
In addition to flooding rainfall, the storms in California will generate areas of damaging winds capable of downing trees and triggering sporadic power outages. Wind gusts of 60 to 80 mph are forecast along the immediate coast and exposed terrain, locally exceeding hurricane force. Strong winds will expand inland Thursday as the Southern California storm reaches peak ferocity.