Dangerous rain storm slams California, state braces for 2nd round

A powerful Pacific jet stream is bringing two dangerous storms fueled by an atmospheric river to the West Coast, the first of which struck Northern California on Wednesday and is pummeling Southern California on Thursday.

This first storm brings a "significant threat to the safety of Californians," Brian Ferguson, spokesman for the state's Office of Emergency Operations Services, warned Wednesday.

And the second storm has the potential to be even stronger than the first, forecasters said.

The first storm dropped 3 to 5 inches of rain on Northern California Wednesday.

Flash flooding was reported overnight and wind gusts topped 70 mph, knocking down trees.

The rain started in Southern California Wednesday night and was at its heaviest Thursday morning.

Rainfall rates reached 1 inch per hour in Southern California and flooded roadways in the Los Angeles area during the morning commute.

The heavy rain and flash flooding threat then moved to San Diego later Thursday morning.

Cal Fire’s Nick Schuler encouraged Californians to have an evacuation plan, a full tank of gas and a packed "go bag."

"Do not drive through moving water, and most importantly, if you are asked to evacuate, please do so without hesitation," Schuler said at a briefing Wednesday.

The heavy rain will leave California Thursday night, but flood watches remain in effect from San Francisco to San Diego through early Friday.

And heavy mountain snow is ongoing in the Sierra Nevada mountains, causing treacherous travel.

The storm will then move through the Southwest's Four Corners region early Friday, bringing heavy rain from Tucson, Arizona, to Phoenix and up to 2 feet of mountain snow.

High wind watches have been issued in parts of New Mexico and western Texas before the storm moves east.

The second storm will strike California on Sunday, bringing another round of heavy rain and flooding from San Francisco to Los Angeles Sunday into Monday.

The slow-moving system is expected to drop several inches of rain over several days.

A total of 5 to 10 inches of rain is possible along the California coast from the two storms, which may result in flash flooding, river flooding, mudslides and rock slides through early next week.

The Sierra Nevadas may see 5 feet or more of snow from the storms.