California atmospheric river: California officials ramp up preparation efforts as powerful storm threatening heavy rainfall and flooding closes in on millions

CNN –

Millions in central and northern California are bracing for an alarming storm that begins Thursday, with heavy rain threatening to cause widespread flooding in areas already reeling from the dangerous fallout from days of snowfall.

More than 17 million people are under a flood watch in California and parts of Nevada, with much of the Golden State under a particularly significant risk of heavy rainfall that could inundate neighborhoods — flooding that could swamp some of the same areas devastated by severe flooding earlier this year.

“An atmospheric river will bring abnormal moisture to California on Thursday and Friday. “The combination of heavy rainfall and rapid snowmelt below 5,000 feet will result in flooding,” the Weather Prediction Center said, adding that “extensive” flooding is likely for millions.

The areas most vulnerable to flooding from rain and snowmelt are creeks and streams in the Sierra Nevada foothills, the forecast center said. “This will lead to difficult travel and combined with an already deep snow pack, could lead to increased impacts from snow depth and weight,” the forecast center added.

The gloomy forecast prompted officials across central and northern California to urge residents to prepare, with residents in one area advised to stockpile essentials for two weeks, while others were asked to use sandbags to protect their properties and clear their waterways to reduce any flooding. the influences.

Here’s what else the storm could bring:

• Heavy rainfall: Most urban areas could see between 1.5 and 3 inches of rainfall totals, according to the National Weather Service in the San Francisco Bay Area. The threat increases for the Coast Ranges and inland hills, where 3 to 6 inches of rain are expected, the weather service added. The Santa Cruz Mountains could see up to 8 inches of rain, while local areas of higher terrain could collect up to 10 inches of rain over an extended period of time.

• Strong winds: More than 15 million people across northern and central California, northern Nevada and southwestern Idaho are under a high wind warning. Wind gusts could reach up to 55 mph in the lower elevations and up to 70 mph across the peaks and mountains. Strong winds could bring down power lines and trees, which would come against the backdrop of thousands of existing power outages from previous storms, whose heavy snow wreaked havoc especially in higher-elevation areas.

• More heavy snow: Parts of the Sierra Nevada mountain range above 8,000 feet could see snow accumulations of up to 8 feet. Also, parts of higher elevations in southern Oregon and the Rocky Mountains in Idaho, Montana and Wyoming could see up to 2 feet of snowfall between Thursday and Friday.

Many of the areas bracing for Thursday’s storm haven’t had a chance to recover from back-to-back rounds of heavy snow that buried some neighborhoods and made roads impassable for days as residents ran out of essential supplies . In hard-hit San Bernardino County, one of the latest storms claimed the life of a resident in a car crash, the county sheriff’s department told CNN on Wednesday.

The impending powerful storm has some local officials on alert days before its expected landfall as a strong atmospheric river, which consists of long, narrow bands of moisture in the atmosphere that transport warm air and water vapor. of water from the tropics.

As the storm hits central California, there is likely to be some urban flooding, flash flooding and flooding from smaller streams and creeks. Eventually, more roads are expected to flood as major rivers rise, according to meteorologist Katrina Hand at the National Weather Service’s Sacramento office.

Officials in San Francisco urged small businesses to clear storm drains, stock up on inventory, use sandbags and ensure equipment is properly stored, according to a news release. Officials also suggested that employers should consider adjusting workers’ schedules for their own safety.

Meanwhile, crews in Merced worked to clear storm drains and shore up creek banks ahead of the storm, city officials said in a release, noting that flooding from the deadly rounds of storm surges that hit much of the state in January, they made the waterways of the city. uncertain.

“The city urges all residents to avoid these waterways and walking paths,” officials said in a statement. “Due to soil saturation and erosion from previous storms, expect to see more debris in stream flows.

Farther west on the coast, five Monterey County parks will be closed Thursday and Friday due to the threat of the storm, officials said in a tweet Wednesday.

Additionally, officials advised residents in the Big Sur area of ​​Monterey County to make sure they have enough food and other essentials for at least two weeks. The Big Sur area, a roughly 90-mile stretch of California’s central coast, is one of the area’s popular tourist attractions with rugged cliffs, mountains and hidden beaches along the Pacific Coast Highway.

In Kern County, home to Bakersfield, fire officials urged residents to create emergency kits and be aware of escape routes and safe areas to seek shelter if necessary. Officials also encouraged the use of sandbags to protect properties.

And in San Luis Obispo, city officials said residents should be informed about flood insurance policies and be prepared to protect their homes and possible evacuations.

In Sacramento, city officials said they plan to open overnight warming centers starting Friday in preparation for expected heavy rainfall and cold temperatures.