Fresno, Calif. – Visitors to Yosemite National Park could see dangerous thunderstorms Sunday afternoon and evening, raising the risk of flash flooding across higher elevations of the Sierra Nevada. Roads, campgrounds, and hiking trails in and around Yosemite, Mammoth Lakes, and Bishop may be impacted as heavy rain and lightning move through.
According to the National Weather Service in Hanford, monsoonal moisture is fueling storm development across the Sierra Nevada and Kern County mountains, with scattered storms also possible in parts of the San Joaquin Valley. The Weather Prediction Center has issued a “slight risk” area, meaning a greater than 15% chance of excessive rainfall that could trigger flooding.
Travelers and park visitors are urged to use caution. The NWS advises staying away from creeks, canyons, and steep terrain prone to debris flows. Lightning will pose an additional hazard for hikers and campers. Authorities recommend moving indoors immediately when thunder is heard and avoiding tall trees and waterways until storms pass.
Storm chances are expected to linger into early next week as moisture continues across the Sierra. Officials warn additional advisories may be issued if storms persist.
