Flood — Mariposa, California

2023-01-15 · near Briceburg, Mariposa, California

Event narrative

California Highway Patrol reported a large boulder washed up onto the roadway on SR 140 in Briceburg.

Wider weather episode

Another strong low pressure system impacted central California as it moved eastward across northern California on January 14. The deeper moisture associated with this system arrived during the evening on January 13 and the precipitation continued across the area until the evening of January 14 when it finally tapered off. Strong upper jet dynamics associated with this system produced a period of widespread heavy precipitation across the area during the afternoon of January 14. Between 2 and 4 inches of liquid precipitation fell over the Sierra Nevada while 1.5 to 3 inches of rain fell over the adjacent foothills. Most of the San Joaquin Valley only picked up between a quarter of an inch and three quarters of an inch of rain due to rain shadowing effects. Several higher elevation SNOTEL stations picked up between 1.5 and 3 feet of new snowfall above 6000 feet with a few inches of snow falling as low as 4500 feet in the Sierra Nevada as cooler air pushed into the area during the evening of January 14. The main impacts from this system came from flooding which was a result of significant rainfall taking place over already saturated soil and continued runoff from previous storms.

View location on OpenStreetMap → (37.6131, -119.9588)

Source: NOAA Storm Events Database, event_id 1065764. Narrative written by the NWS forecast office that issued the report.