CALIFORNIA (REUTERS) - Hundreds of California residents were ordered to evacuate their homes on Wednesday (Feb 13) as rain from a powerful Pacific storm raised the risk of mudslides in areas hit by recent wildfires.
Some areas around Los Angeles could see over 13 cm of rain from the storm, which is being channeled to the coast by a flow of atmospheric moisture known as the “Pineapple Express.” The storm, the wettest to hit California this winter, was set to peak on Thursday and has already sparked flood watches from Arizona to Washington.
Residents of Lake Elsinore, 90km east of Los Angeles got mandatory evacuation orders over risks nearby hillsides scorched by fire in 2018 could turn into rivers of mud and debris that could carry away cars and homes.
Among the hardest hit areas was northern California, with rain driven by winds of up to 120kmh pounding parts of Sonoma County’s wine country.
In the Sacramento Valley, flood warnings were in effect from Chico to Stockton as the warm "Pineapple Express" tropical system brought rain to the mountains, melting snow and swelling creeks.
Cars plowed through standing water on San Francisco streets and water reached the wing mirrors of an abandoned car on a flooded Santa Cruz road.
A woman was injured when a tree fell on a home in Carmel, and falling trees knocked out power to houses in Atherton near Palo Alto, according to tweets from the National Weather Service (NWS) and local authorities.
"The (Pineapple) Express is no joke," said Mr Bob Oravec, meteorologist with the NWS's Weather Prediction Centre in College Park, Maryland.
The system gets its name from a flow of moisture, known as an atmospheric river, that heads east from waters near Hawaii to soak the US West Coast.
The storm will deliver another round of rain and snow through Thursday and Friday, taking new snowfall over 2.4m in some Sierra Nevada mountain passes.
"The big thing that we could see as life threatening would be mountain travel that will become very dangerous," said NWS meteorologist Cory Mueller.
It is one of a string of West Coast storms that have swelled snowpack in California to above-average levels, delighting farmers and skiers following years of drought.
To the north, Oregon and Washington were also pounded with rain and snow, and a section of Interstate 90 in Washington was closed in both directions due to avalanche dangers.
WILDFIRE BURN AREAS RISK MUDSLIDES
The potential 13cm of rain may trigger flash flooding and mudslides, especially near recent wildfire burn areas, the NWS warned.
The problem was not just the amount of rain, but its intensity.
"It's going to be heavy and fast," said Mr Oravec. "Debris flows and mudslides are a risk in any area scorched by the wildfires. There's little to no vegetation to slow that water down."