Hit by a seemingly endless string of damaging storms, California this week faced perhaps the most ferocious storm this season — the state’s 12th atmospheric river storm since Christmas.
On Tuesday, a bomb cyclone hit the Bay Area with hurricane-strength winds. The Federal Aviation Administration implemented ground stops for speeds above 60 mph at Oakland International Airport and San Francisco International Airport. Winds gusted up to 89 mph in the Santa Cruz Mountains.
“It was a violent, sudden wind storm,” said Daniel Swain, a climate scientist at UCLA and the National Center for Atmospheric Research, during a briefing on the storm’s impacts.
Then, according to the National Weather Service, the storm moved south, drenching Southern California with heavy rainfall, and touched down with a tornado in a small town northwest of Los Angeles, damaging about 25 mobile homes. Went.
On Wednesday, the storm lingered over Southern California, sending a second tornado rolling through Montebello, just east of Los Angeles. Rated a 110 mph EF1 tornado, it was the strongest to strike the Los Angeles metro since 1983. At least five people died during these storms, according to the Associated Press.
After three years of drought, California has seen a record-setting deluge that seemingly won’t stop. Rain, once seen as a necessary blessing, has now become a threat to many communities struggling to stay above water. The series of storms have killed dozens of people, closed roads with mudslides and avalanches, dried bone-dry reservoirs, strained levees, and flooded communities.
The dramatic effects of these storms show how influential the atmospheric river system can be for California and how dramatically weather can change in the Golden State, which has a temperamental climate that is both extremely wet and dry. conditions can be produced.
More water is on the way. The state now boasts its biggest snowfall in decades, after years of extreme drought that weakened dams and diverted attention from flood management. Now, those dams will contend with the largest spring runoff in decades.
The most recent storm came on the heels of 11 other atmospheric river-fueled storms that have dumped trillions of gallons of water on the state since the start of the new year. Atmospheric rivers are plumes of tropical moisture that extend thousands of miles into the Pacific Ocean.
Atmospheric rivers often drive extreme weather in California and other western states. They cause more than $1 billion in annual flood damage on average, and about 84% of flood damage in Western states, according to research published last year in Scientific Reports. Climate change is expected to increase atmospheric river impacts in the future because a warmer atmosphere can absorb and transport more water vapor.
During the most recent storm, attention focused on wind damage. But many communities now look nervously at local mountain ranges that hold historic snowpacks.
Storm systems driven by atmospheric rivers are usually very wet and warm. In California, they often produce heavy rain and raise snow levels in the Sierra Nevada Mountains. This can create a recipe for disaster as rain falls on the snow, which can saturate the snowpack or cause the snow to melt rapidly.
Spring melt-out can be extreme. Statewide, mountains in California have more than double the average snow accumulation for this time of year.
A series of exceptionally cold storms in February dropped much snow in parts of the Sierra, especially the central and southern regions. The storm also prompted rare blizzard warnings for lower elevations in Southern California. On February 23, the National Weather Service in San Diego was forced to issue its first blizzard warning on record for the San Bernardino Mountains. It was just one day after the National Weather Service office in Los Angeles issued its first blizzard warning since 1989. This was for areas just 10 miles outside the city, as flakes flew over the iconic Hollywood Sign.
As of Thursday, the Central Sierra Snow Lab was at just over 690 inches for the season. This is the second-highest total on record, surpassing the benchmark season of the 1982–1983 season. The top mark is 812 inches, a record set in 1952.
While this rain and snow have done wonders to end drought conditions, fill reservoirs and fuel wildflower super blooms, a threat looms in April and May.
The recent heavy rainfall combined with Sierra snowmelt could pose a dangerous risk of flooding for communities located below the mountains and in the Central Valley, and especially in California’s San Joaquin Valley.
In its spring outlook, the National Oceanic and Atmospheric Administration said the risk of flooding increased for parts of Central California, including the Central Valley and San Joaquin River Valley.
“California’s historic snowpack, combined with spring rains, is increasing the potential for spring flooding,” said Ed Clark, director of NOAA’s National Water Center.
In some areas, it has already started.
Flood waters in the Tulare Basin have already begun filling farmers’ fields and spilling over into local communities. Agricultural land near Corcoran – near historic Tulare Lake – has been dubbed the “Corcoran Sea”. Drone shots of the area show brown farmhouses surrounded by floodwaters.
Lake Tulare, a dry lake now used for agriculture, may resurface after incredible rainfall. The last time the lake had water was 1997 and before that 1983, both benchmark years in terms of precipitation and Sierra snowpack.
Local communities are fighting the flood waters.
“Our community is completely surrounded by water right now,” said Kayde Kadara, an Allensworth resident and community organizer. Kadara said about one-third of Ellensworth is underwater and many of its 600 residents have been forced to leave.
“We are all nervous. The challenge of melting snow off the mountains is not something we are taking lightly at this point in time.