Hurricane-force winds bear down on California, latest in stretch of extreme weather
LOS ANGELES (AP) — Record-setting flooding over three days dumped more than a foot of rain on parts of northern California, a fire left thousands under evacuation orders and warnings in Los Angeles County, forecasters issued the first-ever tornado warning in San Francisco and rough seas tore down part of a wharf in Santa Cruz.
All of this extreme weather has hit California in the past several weeks, showcasing the state’s particular vulnerability to major weather disasters.
Strong storms Tuesday produced waves that forecasters said could reach 35 feet (10.7 meters) around Santa Cruz. The National Weather Service issued a high surf warning until early evening, cautioning people to stay out of the ocean and away from piers.
For Chandler Price, meteorologist with the National Weather Service in San Diego, these extreme weather events are both typical and unusual for a La Niña winter, a natural climate cycle that can cause extreme weather across the planet. In California, it means a wetter than average northern region and a drier south.
“So far we’ve seen that pattern play out pretty well,” he said, but added, “obviously, you know, the tornado in the Bay Area was atypical. … We haven’t seen that before, at least not for a very long time.”
A storm and wind gusts of up to 60 mph (96 kph) prompted the San Francisco tornado warning that extended to neighboring San Mateo County, which went out to about 1 million people earlier this month. The tornado overturned cars and toppled trees and utility poles near a mall in Scotts Valley, about 70 miles (110 kilometers) south of San Francisco, injuring several people. Tornadoes do occur in California, but they rarely hit populated areas.
In San Francisco, local meteorologists said straight-line winds, not a tornado, felled trees onto cars and streets and damaged roofs.
The storm also dumped significant snow across the northern Sierra Nevada.
Atmospheric rivers
F. Martin Ralph, director of the Center for Western Weather and Water Extremes at the University of California, San Diego, said climate change means that atmospheric rivers, long stretches of wet air that can produce heavy rains, will be responsible for a greater share of California’s yearly precipitation and the periods in between those big events will be drier. These storms are essential for the water supply but can also be dangerous.
“When they are too strong and too many in a row, we end up getting floods,” he said, adding that they drive California’s weather extremes.
During storms this week around Santa Cruz, one man was trapped under debris and died and another person was pulled into the ocean. The surf also splintered off the end of a Santa Cruz municipal wharf that was under construction, plunging three people into the ocean. One swam to shore and the other two were rescued.
A series of atmospheric rivers are expected through the rest of the week. Overall, this pattern is not unusual — these storms regularly produce high winds, heavy snow in the mountains and torrential rain this time of year.
“What’s a little unique about this setup is how closely spaced they are, so there’s not much of a break between them,” said David Lawrence, a meteorologist and emergency response specialist with the National Weather Service.
Bad storms hit the state ahead of Thanksgiving, too, dumping more than a foot of rain (32 centimeters) on Santa Rosa over three record-setting days, according to federal forecasters.
But these storms haven’t stretched very far south, creating dry weather in Southern California that increases fire risk.
One of the state’s most recent blazes, the Franklin Fire left some 20,000 people under evacuation orders and warnings and forced students at Pepperdine University to shelter in place. The blaze was fueled by the Santa Anas, the notorious seasonal winds that blow dry air from the interior toward the coast, pushing back moist ocean breezes.
Most of the destruction occurred in Malibu, a community on the western corner of Los Angeles known for its beautiful bluffs and the Hollywood-famous Zuma Beach. The fire damaged or destroyed 48 structures and is one of nearly 8,000 wildfires that have scorched more than 1 million acres (more than 404,685 hectares) in the Golden State this year.
The Santa Ana winds, which peak in December, have also contributed to warmer-than-average temperatures in parts of the southern state, said Price with the National Weather Service.
“Eighty-degree (26.7 Celsius) Christmases are not entirely uncommon around here,” he added, but “there was a couple of high temperature record breaks in the mountains, which are usually less affected by the Santa Anas, and so those were a little unusual.”
