Santa Barbara County firefighters survey the scene of a large eucalyptus tree
© Mike Eliason/Santa Barbara County Fire via APSanta Barbara County firefighters survey the scene of a large eucalyptus tree that fell into a two-story apartment complex on Bolton Walk in Goleta, Calif.

An atmospheric river over the Pacific is fueling this weekend's rainstorm


The season's strongest storm bombarded Southern California with hours of rainfall, flooding freeways and forcing evacuations in the region's wildfire burn areas.

High rainfall rates could trigger mudslides, debris flows and rock slides, and strong winds will pummel the region. The storm is being fueled by a long band of moisture over the Pacific, acting like a conveyor belt carrying rain to the West Coast.

The result is prolonged periods of rain and downpours that could triggered flash flood warnings, most of which expired Saturday afternoon. A warning remains in effect until about 4 p.m. for Orange County.

Evacuation orders were in effect for parts of Southern California, including burn areas in Ventura, Santa Barbara, Orange, Riverside and Los Angeles counties.



In Santa Barbara County, part of the 101 Freeway was closed due to flooding and mud on the road. It's the same area where mud and boulders came down in heavy rain just over a year ago. That disaster in January 2018 killed 21 people, and two others have never been found.

Storm totals are expected to reach 1.5 to 3 inches for the coast and valleys, 4 to 7 inches for mountains and foothills. Expect the heaviest rain along coast-facing mountain slopes.

As for the winds, damaging gusts are possible through the day. Most areas will be blasted by 40 to 60 mph gusts, but higher elevations might see gusts up to 80 mph.

"I really want to stress this message. This is a significant and dangerous storm system that we have on Saturday, no lighting, we just have some very heavy rain," said NBC4 forecaster Anthony Yanez.

As for snow, a winter storm warning is in effect until Sunday afternoon in the mountains and 6 to 12 inches of snow are likely to fall from 5,500 and 7,00 ft. Snow accumulations from 8 to 16 inches are possible above 7,000 ft. and up to 2 ft. could accumulate above 7,500 ft.

"In the mountains, plan on dangerous travel conditions," De Leon said.

Rain showers are expected to linger through Sunday afternoon, then the third storm front will bring lighter precipitation Monday morning through Tuesday.

The storm -- the second of three over just a few days -- is coming from the Gulf of Alaska. It's tapping into a band of moisture known as an atmospheric river stretching from Hawaii to California as a low pressure system parks itself over California.