Flash Flood — San Bernardino, California

2010-01-21 · near Hesperia Arpt, San Bernardino, California

Event narrative

Heavy rain in the High Desert produced widespread flash flooding in the cities of Adelanto, Victorville, Hesperia, and Apple Valley. This area, on average, receives about 5 to 6 inches of rain per year. Most of these areas saw that amount of rain in just a few days. Runoff from the San Bernardino Mountains and a rapidly rising Mojave River may have contributed to some of the flooding. Numerous homes, schools, parks, and roads sustained minor to major damage. Some reports claimed as many as 124 homes in San Bernardino County were damaged. On January 28, the Governor of California declared a State of Emergency which included San Bernardino County.

Wider weather episode

The fourth, and strongest, in a series of winter storms pounded the region on the 21st and 22nd, bringing another round of gusty winds, heavy rain, thunderstorms, several feet of snow in the mountains, and flooding throughout the CWA. Many roads in the region were closed due to flooding and mud on the roadway, as well as fallen trees. In Horsethief Canyon Ranch in Temescal Valley dozens of large trees were uprooted due to the heavy rain and winds, though no other damage was reported. The storm was marked by record-breaking low pressure. Lindbergh Field recorded a sea level pressure of 987.1 mb, shattering the old record of 994.6 mb set on March 3 1983.

View location on OpenStreetMap → (34.3912, -117.3821)

Source: NOAA Storm Events Database, event_id 212972. Narrative written by the NWS forecast office that issued the report.