Powerful Pacific tempest clobbers storm-battered California

SANTA CRUZ, Calif. -

A strong late-season Pacific storm that brought damaging winds and more rain and snow to saturated California has been blamed for two deaths and forecasters said additional flooding was possible Wednesday in parts of the state.

Tuesday's storm blasted the San Francisco Bay Area with powerful gusts and downpours, pounded Sacramento -- the state capital -- with intense hail and triggered a rare tornado warning on the Southern California coast.

The storm was gradually tapering off in California from north to south as the expansive system pushed inland across the Southwest, the Four Corners region and the central and southern Rockies, the National Weather Service said. On Tuesday, some residents of north-central Arizona were told to prepare to evacuate because of rising water levels in rivers and basins.

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A tornado warning based on radar was issued for the Point Mugu area west of Malibu during the evening after meteorologists warned that conditions were favourable for creating waterspouts that could move ashore. The warning was later cancelled and the Ventura County Sheriff's Office tweeted there was no evidence a tornado touched down.

The wind and rain mayhem from San Francisco Bay south to Monterey Bay on Tuesday was caused by an extraordinary drop in barometric pressure over the eastern Pacific that meteorologists described as "explosive cyclogenisis."

"Wow. Even by the standards of what has turned out to be one of our most extraordinary winter seasons in a very long time, yesterday ... stands out," the Bay Area weather office wrote.

Trees and power lines were blown down. Windows were blown out from two San Francisco high-rises, NBC Bay Area reported. Ferry service was disrupted because conditions were too rough. Three barges got loose and damaged a bridge.

An Amtrak commuter train carrying 55 passengers struck a downed tree and derailed near the East Bay village of Porta Costa. The train remained upright and nobody was injured, Amtrak and fire officials said.

In the Bay Area community of Portola Valley, a man driving a sewer truck was killed when a tree fell onto the vehicle, the California Highway Patrol said. And in the community of Rossmoor, a driver was injured and a passenger died after a large tree fell onto a car, the Contra Costa County Fire Protection District said.

In the Monterey Bay region, Santa Cruz County was blasted with gusts up to 80 mph (129 kph) at midday. Along the coastline of the Monterey Bay National Marine Sanctuary, ocean foam blew across the roadways like large snowflakes.

Wind gusts reached 76 mph (122 kph) in Santa Cruz mountain communities, including Boulder Creek.

Resident Frank Kuhr waited for hours Tuesday afternoon at a downtown supermarket for crews to remove large redwoods that blocked a highway. "Trees are down everywhere," Kuhr said. "The wind has been unbelievable. Branches were flying through the air, and folks could hear trees just falling and cracking."

 "This one's a doozy," Kuhr said.

The 1.4 inch (3.5 centimetres) of rain that fell on downtown Los Angeles broke the March 21 record of 1.34 inches (3.40 centimetres) set in 1893.

Some 121,000 customers were without electricity early Wednesday throughout the state, according to PowerOutage.us.

The National Weather Service said Tuesday's storm, which came on the first full day of spring following the state's extraordinary winter, was a Pacific low-pressure system interacting with California's 12th atmospheric river since late December.

California's unexpected siege of wet weather after years of drought also included February blizzards powered by arctic air.

The storms have unleashed flooding and loaded mountains with so much snow that roofs have been crushed and crews have struggled to keep highways clear of avalanches.

The Mammoth Mountain resort in the eastern Sierra Nevada announced that it will remain open for skiing and snowboarding at least through the end of July.

With a season-to-date snowfall of 634 inches (16.1 meters) at the main lodge, it was likely just one storm away from breaking the all-time record of 668 inches (16.9 meters) set in the 2010-2011 season.