LOS ANGELES — The first of two atmospheric river storms descended Friday on California, prompting widespread evacuation orders as it flooded creeks and rivers and dropped warm, heavy rains atop the state’s near-record snowpack.
Gov. Gavin Newsom requested an emergency declaration from President Joe Biden, which would authorize federal support for state and local responses to the storm.
Newsom on Thursday proclaimed a state of emergency in 21 counties, activating the California National Guard and other state agencies to respond to storm-related emergencies.
“California is deploying every tool we have to protect communities from the relentless and deadly storms battering our state,” Newsom said. “In these dangerous and challenging conditions, it is crucial that Californians remain vigilant and follow all guidance from local emergency responders.”
By Friday morning, the “Pineapple Express” storm — which is gathering warm, subtropical moisture from Hawaii — had made landfall in several communities as it carved a path from the Central Coast toward the southern Sierra.
“This is an unrivaled, unparalleled weather event not experienced in several decades,” Kris Mattarochia, a meteorologist with the National Weather Service in Hanford, said during a briefing in Fresno. “There will be high water and areas that are usually not impacted. So everyone needs to be ready. … Combined with snow melt, the Kings River, along with smaller streams like Mill Creek, will be pushed to limits which are unimaginable.”
At least seven of the state’s river systems were forecast to flood, including the Russian River at Hopland, the Salinas River at Bradley and Spreckels, the Carmel River at Robles Del Rio, the Merced River at Stevinson; the Cosumnes River at Michigan Bar and Bear Creek at McKee Road.
Several of the rivers flooded in January, when a series of nine back-to-back atmospheric rivers sent water rushing over levees and onto properties and roadways. The storms contributed to nearly two dozen deaths, including people trapped by floodwaters and killed by falling trees.
Officials are hoping to prevent a repeat of that deadly scenario and were making strategic releases from the state’s swelling reservoirs to make room for incoming flows. At Lake Oroville, California’s second-largest reservoir, officials had already increased releases from the Hyatt Power Plant and were planning to open the main spillway Friday afternoon — marking the first use of the spillway since April 2019.
Operators also were ramping up releases from Lake Shasta, Millerton Lake and Folsom Lake, among others, to prevent overtopping. Folsom Lake primarily acts as a flood-control system for the Sacramento area.
But more than two dozen river systems were already above “monitor stage” Friday morning, indicating the potential for overtopping and flooding in low-lying areas, according to the National Weather Service.
Nearly 90 flood watches and advisories were in effect across the state, including urgent flash flood warnings in portions of Tulare, Fresno and San Luis Obispo counties. Evacuation warnings were in effect for dozens of communities as reports of rapidly rising rivers, streams and creeks rang out.
“A dangerous excessive rainfall event is underway across much of Central California,” the weather service said. Rainfall totals of up to 9 inches are possible in many areas, with the highest flood risk in coastal areas from Salinas to San Luis Obispo and throughout the Central Valley.
In Santa Cruz County, the San Lorenzo River had already crested Friday morning, prompting evacuation orders for Felton Grove, Paradise Park and Soquel Village due to flooding. Flash flood warnings were in effect in San Luis Obispo County, where isolated rainfall totals of up to 15 inches were possible and streams near Cambria and San Simeon were already reaching concerning levels.
In the Merced County town of Planada, officials went door to door to many homes Wednesday and Thursday to warn of possible disaster. The town was almost entirely flooded after a levee broke in January.
“People are full of fear,” County Supervisor Rodrigo Espinosa said Thursday as he returned from watching crews lay sandbags at nearby Bear Creek. He hoped that the sandbags, debris clearance and other infrastructure improvements would prevent a worst-case scenario.
And in Fresno, officials warned residents to be prepared for rainfall that would test the limits of the county’s water management systems.
“The soils are so saturated from all the rain we’ve received, it will not take much at all for those trees or power lines to perhaps fall across roadways, fall on top of homes, fall on top of other infrastructure,” said Mattarochia, the meteorologist. “We’re going to have enhanced wind gusts, and we’re going to have enhanced rainfall rates, which can exacerbate the situation over some of these hot spots, like Mill Creek, like Kings River.”
The county had previously set up a shelter for evacuees at Reedley College, but because of its proximity to the Kings River, officials decided to move it farther inland to the Sanger Community Center.
“We want everyone to know that this is not a normal situation. This is something that is completely outside the realm of even possibilities that we can imagine as meteorologists,” he said.
Indeed, the incoming storm will fall atop soaked soils and some of the deepest snowpack California has recorded. Both can exacerbate the potential for runoff and erosion.
In high-elevation areas, the biggest threat from the storm will probably be structural damage as rain makes the snowpack even heavier, UCLA climate scientist Daniel Swain said during a briefing. The state has seen a spate of roof collapses from heavy snow, including a grocery store providing crucial supplies in Crestline.
“There really will be significant melting of the snowpack — which is substantial at those elevations — as heavy rain falls into it,” Swain said. “But really, the main flood threat is coming from the fact that the storm is just going to bring a significant amount of rainfall in its own right.”
The threat won’t ease when this storm moves out this weekend. Another atmospheric river is expected to follow early next week, and there is a potential for a third around March 19, according to state climatologist Mike Anderson.
