FRESNO (CBSLA.com/AP) — The beautiful Yosemite Valley could get ugly Saturday as an enormous storm arrives that could be the biggest to slam central California in years.
Although very heavy rain and snow from a so-called “atmospheric river” is expected to inundate northern and central California this weekend, only light rain will fall in most of Southern California. The heaviest rain will remain in northern and Central California as has been the case with earlier storms.
Rangers at Yosemite National Park closed all roads leading to the park’s valley floor, a major attraction for visitors from around the world eager to view gushing waterfalls and gaze up at towering granite rock formations such as El Capitan and Half Dome.
Photographer and rock climber Josh Hilling who lives in the foothills below the park, spent recent days chopping wood and stocking up on groceries.
“If you live long enough in this canyon, you experience lots of natural disasters — floods, fires, rock falls,” Hilling said Friday from his family’s home in El Portal.
Unlike many of the storms that strike California, the one approaching hails not from the Gulf of Alaska but from the west, produced by a long and narrow column of water vapor in the atmosphere called an atmospheric river. Such phenomena account for between 30 and 50 percent of annual precipitation on the West Coast, says the NWS.
Rain is expected Monday and possible Wednesday in Los Angeles, the NWS reports. Monday’s rainfall will be heavier in the Southland than Saturday’s, may last 3-5 hours and could produce a half-inch of rain just in downtown L.A.
A huge storm in 1997 flooded Yosemite Valley, closing the park for two months and washing out roads, lodging and campgrounds. This weekend’s storm is not expected to be quite that severe.
The closure is expected at least through Sunday. Other parts of the park remain open, but rangers caution visitors to be aware of ice and falling debris on the roads.
On Friday, rangers stood watch for flooding along the Merced River, a major river flowing through the valley, park spokeswoman Jamie Richards said.
“We’re prepared,” she said, adding that they’re accustomed to life in a giant canyon with frequent, rain, snow, ice and rock falls. “We have a lot of things we deal with on a frequent basis.”
Rangers are keeping an especially close eye on Pohono Bridge, which crosses the Merced River. Flooding there starts when the water level reaches 10 feet, but the watermark hit just 4 feet Thursday, Richards said.
Elsewhere, the onslaught of storms sent residents in California and Nevada scrambling to gear up for heavy rain and expecting swollen rivers and toppled trees this weekend.
On the central coast in Santa Cruz — where up to a foot of rain could fall in places — officials have set up sand bag stations for residents.
“We’re giving them a shovel and the sand and showing them how to fill them up,” said Jason Hoppin, a Santa Cruz County spokesman. “We haven’t seen rain like this in a long time.”
This stormy weather comes as California enters its sixth year of drought. Each storm is welcomed, but officials say several more like this are needed to replenish depleted groundwater supplies.
The strong wet season began in October with more rain falling than in three decades, mostly in Northern California. Los Angeles is experiencing the wettest winter in six years, forecasters say.
Forecasters anticipate the atmospheric river could dump up to 8 inches of rain from Sonoma to Monterey counties.
The storm’s mild temperatures will drive up the snowline to above 9,000 feet throughout the Sierra Nevada, causing runoff in the lower elevations, said Zach Tolby, a meteorologist with the National Weather Service in Reno.
The Truckee River, which flows from Lake Tahoe through Reno, is forecast to rise to its highest point in more than a decade, according to the weather service, which has issued a flood warning.
Residents and business owners throughout the Reno-Sparks area filled tens of thousands of sandbags.
Flooding could rival the winter of 2005-2006 that sent 5 feet of water into the Sparks industrial area made up of warehouses and manufacturing plants. Crews worked to secure storage drums filled with hazardous materials to stop them from floating away as they have in past floods.
“This is a classic set up for us for flooding,” Tolby said. “We’re definitely expecting a very wet weekend.”
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