Yosemite Valley will close to the public Friday ahead of a powerful storm that could bring flooding to the area, officials said.
Visitors were asked to leave by 5 p.m. and all overnight reservations were canceled through Saturday night, according to Yosemite National Park officials who say the storm may cause "significant impacts."
After the storm passes, authorities will assess road and facility conditions to determine when Yosemite Valley, home to many of the park's picturesque waterfalls and cliffs, can reopen.
Access to Yosemite Valley will be closed on Big Oak Flat Road at the Foresta Road Junction, on Wawona Road at Chinquapin and on Highway 140 at the park boundary in El Portal, officials said.
Campgrounds in Wawona, Hodgen Meadow, Crane Flat and El Portal are expected to stay open, along with the Big Trees Lodge, El Portal Market and the El Portal gas station.
The incoming "atmospheric river," a long plume of water vapor from the Pacific tropics, is expected to bring between 3.5 and 4 inches of rain to Yosemite Valley through Saturday, with the heaviest rain coming late Friday and into the early morning hours, said Jim Bagnall, a meteorologist with the National Weather Service in Hanford.
Forecasters said the Merced River at Pohono Bridge, currently running about 4 feet, is expected to rise close to 15 feet. Flooding occurs at about 10 feet, Bagnall said.
"That's one of the reasons that they're closing the campgrounds, getting the people out of there," Bagnall said. "With all that rain there's a possibility of flooding, mudslides and rockslides, rivers and creeks rising out of their banks."