More than a dozen giant sequoias (and many other trees) fell during the Mono Wind event on January 19, 2021/NPS

Editor's note: This updates the number of sequoias that were downed by the winds, and gives more detail on "Mono Wind" events.

A wind storm powerful enough to down more than a dozen massive sequoia trees at Yosemite National Park in California has led to the park's closure through the weekend as assessments and repairs are tackled.

"Mono winds" dive out of the High Sierra from the east, typically between October and April but especially during December and January, and funnel through the foothills with speeds that can approach 100 mph, according to a paper put out by the National Park Service and National Weather Service.

"The most common danger from Mono Winds is trees falling down. Fallen trees can easily strike visitors as well as obstruct traveling on roads and make navigating trails difficult," the agencies said. "Even campers in enclosed structures such as cabins can be at risk."

While Yosemite officials have not said how fast the winds were with the event that swept across the southeastern corner of the park Tuesday evening, 15 sequoia trees in the Mariposa Grove, including one of the "Monarchs," were downed, said Frank Dean, president and CEO of the Yosemite Conservancy, on Friday.

Sequoia trees typically have shallow roots, making them particularly susceptible to high winds. But the gusts also downed Ponderosa pines and incense-cedar trees. 

The restroom building in the Mariposa Grove was damaged by a tree during the Mono wind event on Jan 19, 2021/NPS

A boardwalk in the Mariposa Grove was damaged by a fallen Ponderosa pine during the Mono wind event on January 19, 2021/NPS

Falling trees damaged vehicles in the park/NPS

Buildings in the Wawona area also were damaged by the wind storm/NPS

Park officials did not immediately return a phone call Friday seeking additional information on the damage to the park. Corporate communications staff for Aramark Leisure, which runs the park's lodges and restaurants, had no information on whether the event damaged lodging facilities in the park, and directed calls to the park staff.

While the coronavirus pandemic has left the park's campgrounds and lodgings closed, Yosemite has been open for day visitors. 

When the park reopens, visitors will be able to enter the park using El Portal Road (Highway 140), Big Oak Flat Road (Highway 120 from the west), and Hetch Hetchy Road. Areas south of Yosemite Valley (including Badger Pass, Wawona, Mariposa Grove, South Entrance, and Wawona Road) will remain closed until further notice.