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Warmer storms prompt concerns about rapidly melting snow

LA County says it's prepared for any flood concerns as warmer storms approach
LA County says it's prepared for any flood concerns as warmer storms approach 03:22

White-out conditions plagued the state last with regions from Tahoe to Southern California withstanding strong storms that buried homes and businesses and stranded people for days under the deluge. 

Amid the blizzard conditions in mountain areas, the historically cold storms also brought snow to lower elevations. However, now, with warming storms on the way concerns surrounding flooding have risen. 

"It now looks increasingly likely that a potentially significant and very likely warm atmospheric river will probably affect some portion of Northern or Central California sometime between late Thursday and Saturday," said Dr. Daniel Swain, a climate scientist with UCLA. "There's a lot of uncertainty at this point regarding how intense it will be, how prolonged it will be."

Lower elections in Northern California between 2,000 to 4,000 feet are the biggest concern right now. 

"those elevations are going to see some significant potential for runoff issues and flooding," said Swain. 

Warmers storms have another serious implication for the state's water supply. 

"Warm rain can wash it all out," said Felicia Marcus, a Landreth visiting fellow at Stanford University.

Marcus, who is the former Chair of the California Stae Water Resources Control Board, said if the state's snow pack melts too fast, we will likely lose a lot of it. 

"You lose a bunch of that bank account that we really are going to need in the coming months through the year," said Marcus. "So if that melts out slowly, on a schedule we prefer, to refill the reservoirs as we use them, replenish the streams and flow down for the groundwater to be replenished — because that is by far our largest storage."

Lake Oroville, outside of Sacramento, was devasted by years of drought. But after months of rain, the basin, which is one of California's largest reservoirs, is now 73% full. However, on Friday it may be so full, the state is preparing to open the spillway to remove excess water. 

In Los Angeles County, Public Works said they are ready if the warmer storms slam Southern California. 

"A lot of people don't realize the L.A. County Flood Control District was founded in 1915 to deal with really catastrophic storms that came about in that period of time," said spokesperson Steven Frasher. "There are 14 dams in the foothills that protect the Greater Los Angeles Basin and allow us to capture stormwater behind those dams and reservoirs."

However, in the San Bernardino mountains where a historic amount of snow fell, public works crews are working to prevent any problems like flooding. 

The area was deluged with over 100 inches of snow after the powerful storm created blizzard conditions and prompted closures throughout the San Bernardino mountains. 

Incoming storm prompt flood concerns in the San Bernardino mountains 03:00

Director of Public Works Brendon Biggs said San Bernardino County officials said the flood area safety task force has been meeting daily. 

"Our team is ready to handle any kind of inquiries and potential flooding, said Biggs. 

Biggs added that there are no flood control facilities only natural drainage that flows through private property. 

KCAL News meteorologist Paul Deanno explained what it would take to get serious flooding.

"If a storm comes along and drops, let's say, half a foot of rain in the mountain and has a snow level of like 9000 feet that's kind of the worst-case scenario," said Deanno. "Not only will you have half a foot of rain falling but all that snow, or even half of that snow, melted at once that's adding two, three or four inches of liquid equivalence. Now, a six-inch rainstorm becomes a 10-inch rainstorm."

Luckily, an upcoming storm set to hit Southern California this weekend is not expected to bring those types of conditions.

Experts stress the hope is for slow and steady snow melt through the spring. They also hope that no heat waves hit the region so the reservoirs can hold the runoff and the ground can absorb as much as possible.

To incentivize private properties to clear snow, Sam Bernardino County is offering to reimburse residents and business owners up to $500.  

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