Atmospheric river slamming California with widespread flooding, ‘direct threat to life and property’
One week after a deadly bomb cyclone brought heavy rain and flooding to California, and then another storm soaked the region over the weekend, the Golden State is again the target of a powerful atmospheric river storm that forecasters say is a "direct threat to life and property."
And more storms are on the way for later this week
But Monday's storm that is again bringing heavy rain and damaging winds to the Golden State is the strongest, with the FOX Forecast Center expecting the flooding threat to be far more serious than that seen from previous storms over the past few weeks.
Flash Flood Warnings have already been issued in California, including in Santa Cruz County.
The National Weather Service issued a Flash Flood Warning for the county until 9:45 a.m. local time. Forecasters say life-threatening flash flooding of creeks and streams, urban areas, highways, streets and underpasses are being flooded due to the heavy rain.
Many residents have already been told to evacuate their homes because of flooding concerns with this powerful and high-impact storm.
Sacramento County ordered its residents living in Wilton to leave the area on Sunday because of fears that rising rivers may spill out of their banks and onto roads in town, which will cut off evacuation routes.
Santa Barbara County also issued an evacuation warning for areas in the southern part of the county associated with the Alisal, Cave and Thomas fires. That warning comes as concerns grow that the heavy rain could lead to mudslides and debris flows in burn scar areas.
County officials warned residents that the evacuation warning could be upgraded to an evacuation order, so residents should keep up with the latest warnings from officials.
Atmospheric river bringing double, or even triple the amount of typical moisture in the air
So, why is this storm different than the others?
"Typically, California sees about five to seven good atmospheric rivers each year that contribute to our water supply," said Brooke Bingaman, lead forecaster with the National Weather Service in San Francisco. "What's different with this one that's coming, the amount of moisture in the air that's approaching the West Coast is at least 250-300% of what we normally see in the air as it's approaching the West Coast."
What else is unique with this storm, Bingaman said, is the fact that California has been hit with so many of these storms.
"So, we just keep piling on these waves of rain after rain," she said. "So, that's what's making this storm more unique."
And because of the already saturated soils from the previous storms, streams will likely flood quickly. According to the FOX Forecast Center, all of that water will eventually make its way into the larger rivers, leading to a high chance of widespread flooding across the northern half of the state.
With concerns growing that this storm could have a major impact on the state, California Gov. Gavin Newsom said he has been in close contact with the White House to ensure the state has the aid it needs to help prepare for the atmospheric river storm and to respond to damage during and after the storm. Sunday evening, President Biden approved an emergency declaration for California.
Newsom is also asking Californians to listen to local warnings and be prepared to respond if evacuations are ordered.
Heavy rain expected to lead to widespread flooding in California
Several inches of rain are expected to fall during this storm, likely leading to widespread flooding as rainwater flows into smaller rivers and streams that will eventually move into larger rivers that could flow out of their banks.
(FOX Weather)
Many areas, including the San Francisco Bay Area and Sacramento, will likely see 3-5 inches of rain through at least Wednesday, according to the FOX Forecast Center.
To the north in Redding, about 2-3 inches is expected, with some locally higher amounts.
Higher totals are expected further inland and south, including Fresno, where 5-8 inches of rain could fall.
Heavy rain is also expected to move into the Los Angeles area, where 2-3 inches of rain could fall over the next few days with as much as 8 inches in the mountains surrounding the L.A. Basin.
Flash flooding is possible across most areas of California from the California-Oregon border south through the Los Angeles Basin.
However, the risk of flash flooding is much higher across most areas of central California. This includes cities from Sacramento and San Francisco south through Monterey, Fresno, Santa Barbara and even Los Angeles.
Severe weather even a threat with latest atmospheric river
Severe weather is also possible across areas stretching from the Mendocino and San Francisco Bay areas south through Monterey and King City, with scattered thunderstorms capable of producing heavy rain and brief busts of damaging winds.
And while the threat is low, there is also the possibility that a tornado could form with any of the stronger storms that develop during Monday into Monday night. The threat moves into Southern California on Tuesday.
California Tornado Threat (FOX Weather)
Strong winds are also expected across the region, with some areas closer to the coast seeing gusts as high as 80 mph.
Those wind speeds are high enough to bring down trees and utility lines, which will likely again lead to widespread power outages. California had around 500,000 without power at the peak of the latest storm to strike over the weekend.
High Wind Warnings are in effect from the Sacramento and San Francisco Bay areas, south through Bakersfield and north of Los Angeles. Wind Advisories are in effect for inland areas of central California.
And the higher elevations of the Sierra Nevada are expected to pick up several feet of snow from these storms.
The higher elevations could see anywhere from 2-10 feet of snow.
Another round of heavy rains are forecast for Northern California on Wednesday, then the region is expecting a bit of a break with lighter rain showers at the end of the week. However, another potent storm is looming for the weekend with potential renewed flooding threats.