Flood Watch Issued for Yosemite as Storms Move Into California

Parts of the central and southern Sierra Nevada are under a flood watch as a wet storm system moves into the region this weekend.

The National Weather Service issued the watch Friday morning for Yosemite National Park, Yosemite Valley, the Mariposa–Madera Lower Sierra, the San Joaquin River Canyon, and the Upper San Joaquin River. The watch goes into effect Saturday at 4 p.m. and remains in place through Monday, Dec. 22, at 4 p.m.

According to the NWS, excessive rainfall could lead to flooding in rivers, creeks, streams, and other low-lying or flood-prone areas. Officials warn that runoff may increase quickly, especially where soils are already saturated, and low-water crossings could become impassable.

A flood watch means conditions are favorable for flooding, not that flooding is guaranteed. Residents and visitors are urged to stay alert, monitor forecasts, and be prepared to take action if conditions worsen or flood warnings are issued.

Those camping or recreating in the Sierra should avoid setting up in low-lying areas and be ready to move to higher ground if water levels rise. Drivers are reminded never to drive through flooded roads—just a foot of fast-moving water can sweep away most vehicles.

With winter storms returning to the mountains, officials emphasize that preparation and awareness are key. Checking conditions before traveling and adjusting plans as weather develops could make a critical difference over the next few days.