Yosemite National Park braces for flooding ahead of atmospheric river storm

ByLeslie Brinkley KGO logo

Wednesday, March 8, 2023

Yosemite braces for flooding ahead of atmospheric river storm

The approaching California atmospheric river storm could bring heavy rain to Yosemite National Park, which could melt snow and trigger flooding.

YOSEMITE NATIONAL PARK, Calif. (KGO) -- The earliest possible date for Yosemite National Park to reopen to the public is Monday, March 13. But, park crews aren't just plowing snow - they're bracing for the next storm system.

Yosemite shut down Feb. 25 because of blizzard after blizzard. And now, there's an atmospheric river on the way.

"There's nowhere for visitors to park right now. When I went into Yosemite Valley yesterday, it's crazy," park spokesperson Nancy Phillipe said. "There's nowhere to park, the snow levels are so high. We are doing damage assessments. We are digging out fire hydrants and propane tanks."

It's all hands on deck to plow the snow but at the same time, crews are setting out sandbags because the approaching storm could include heavy rain at elevations up to 8,000 feet, and that could trigger a massive snow melt event.

The same scenario took place in Jan. 1997, where warm rain accelerated snow melt. The runoff caused the Merced River and creeks to overflow, taking out bridges and roads, destroying half of the accommodations in Yosemite National Park and half of the campgrounds. 2,100 visitors were stranded, and the park was closed for two months.

VIDEO: Snowfall reaches 15 feet in some areas of Yosemite National Park

"I heard one of my colleagues say, 'You know you've been here a long time when a 100-year event is happening again,' and we are definitely concerned about that. Looking at the modeling, I believe there's more snow than we had in 1997,"' Phillipe said.

The vice director of the UC Davis Center for Watershed Sciences said, "For Yosemite Valley, there's not a large reservoir upstream to dampen that snowpack snow melt. I think you should look for road closures. Overall, we just have to wait and see."

Phillipe adds, "We have plans in place from the 1997 flood with best case scenarios and where to set up sandbags. All the plans we need to set up throughout the entire park."

If all goes well, Yosemite could reopen on March 13. If there is flooding, then all bets are off. It could be closed for longer.