This week’s ‘Pineapple Express’ storm brings heavy rain, sparks flooding concerns across California – Daily News

California Snow Videos: Balcony Jumping, Bridge Snow Shoveling, and Turkey Spotting

Winter 2023 is not over yet. Not a long shot.

Meteorologists and climate scientists said Monday that an atmospheric river storm is likely to hit northern California late Thursday through Friday, with heavy rain likely in the Bay Area and high elevations in the Sierra 1. ~3 feet of fresh snow is more likely, and flooding is at risk as warm rains hit the state’s huge snowpack.

Details about Arashi, a classic “Pineapple Express” event taking place more than 2,000 miles from Hawaii, are still unclear.

But last weekend, computer models began to show that chance had increased from about 10% to about 70% now, said UCLA climate scientist Danielle Swain.

“At this point, there is a lot of uncertainty about how intense the storm will be, how long it will last, whether it is likely to have an impact, and whether it will be followed by additional warm storms. is in the air, but there is growing confidence that warmer rains of some magnitude will arrive later this week.”

The storm was most likely a 3 on a scale of 1 to 5, and potentially a 4, said director of the Western Center for Meteorology and Extreme Waters at the University of California, San Diego, and an atmospheric Marty Ralph, one of the nation’s leading experts on rivers, said.

“You can feel the south from San Diego to the Russian River,” Ralph said.

Both Ralph and Swain said the latest storm alone is unlikely to melt the massive Sierra snowpack on a large scale. Absorbs a fair amount of rain.

But computer models also indicate that two or three more atmospheric river storms are likely in the next 10 days, Ralph said.

“It could be like January when the atmospheric rivers flowed continuously,” he said. “That’s what I’m looking for. The biggest risk is the possibility of another series of atmospheric river storms because of this.”

Many of the state’s largest reservoirs still have room to hold incoming water. During three years of drought their levels became so low that the largest are not yet fully filled. On Monday, Lake Shasta near Redding, California’s largest reservoir, was 61% full. Auroville, his second largest in Butte County, was 74% filled.

That wasn’t the case in 2017 when Auroville flooded and a spillway burst, forcing more than 180,000 neighbors to evacuate.

Hoping to reduce the chances of a similar event, dam operators have increased water discharge from several reservoirs in recent weeks, including Folsom, northeast of Sacramento, and Millerton, near Fresno, to bring more water into the water. I created a space for

“We have many reservoirs in place around the state to prepare for this storm,” Ralph said.

How much rain is expected? From Thursday night through Sunday, the NOAA expects 2 to 3 inches of rain in San Francisco, Oakland and San Jose, and 4 to 6 inches in the Santa Cruz Mountains and Big Sur. small stream.

One to three inches in the Central Valley and three to six inches in the Sierra foothills, says Katrina Hand, a meteorologist at the National Weather Service in Sacramento. She said there will be 5,000 to 6,000 feet of snow.

California’s huge snowpack is a boon, continuing to melt and fill the state’s largest reservoir until spring.

They worry that a series of warm tropical storms could melt faster than usual, causing devastating floods like those seen in 1997.

That year, several warm “Pineapple Express” storms drenched the Sierras around New Year’s Day. Yosemite Valley suffered the worst flooding in a century. The entire campsite was washed away. Half of Yosemite Lodge was destroyed. Across the Central Valley, large reservoirs overflowed and released water uncontrollably. Levees breached, causing massive flooding in Marysville, Yuba City, and other areas. When it ended, his 48 of California’s 58 counties were declared disaster areas, with total damage reaching her $1.8 billion.

Hand said Friday’s storm alone won’t do that.

“I’m not thinking of recreating 1997,” she said. “This storm is neither strong nor warm.”

California’s severe three-year drought has seen nine atmospheric river storms between Christmas and mid-January cause reservoir levels to rise and cause severe flooding, killing at least 21 people. It killed more than 750 people, caused landslides and destroyed roads before being largely cleared in many northern and coastal areas. We urged President Biden to visit and investigated the damage.

Most of February was dry. But in the past two weeks, several powerful new storms have brought more rain to cities from the Bay Area to Los Angeles, blanketing the Sierra Nevada Mountains with 16 feet of fresh snow, driving Yosemite National Park, Interstate 80 , Highway 50 and even the ski area closed. There were several days at the resort where the lifts did not work due to a blizzard.

Swain said Friday’s storm could cause “unusual problems” in some mountainous areas.

“It is almost certain that we will see at least mild or moderate flooding” in Sierra foothill communities and some urban areas, Swain said, adding, “The events from Friday to Saturday are similar to the events we have seen in January.” I think there will be less flooding than there will be.”

However, he said he is looking very carefully at next week’s forecast.

“If the storm train lasts long enough to keep warm rains on top of huge snowpacks, that’s going to be a big problem,” Swain said.