Tropical Storm — San Diego County Valleys, California

2023-08-20 · San Diego County Valleys, California

Event narrative

Tropical Storm Hilary produced widespread tropical storm-force winds across Southern California from early morning on August 20 through the early overnight hours into August 21. The following are the top wind gusts reported across the San Diego County Valleys:

Hauser Mountain: 78 MPH (8:20 AM 08/20)

Hellhole Canyon (SDGE): 70 MPH (11:40 AM 08/20)

Dye Mountain (SDGE): 69 MPH (9:20 AM 08/20)

Poomacha (SDGE): 67 MPH (9:20 AM 08/20)

Round Potrero (SDGE): 65 MPH (9:00 AM 08/20)

Cuca Ranch (SDGE): 64 MPH (11:40 AM 08/20)

Witch Creek (SDGE): 63 MPH (9:20 AM 08/20)

Santa Ysabel Ranch (SDGE): 62 MPH (10:40 AM 08/20)

Mateo Ridge: 61 MPH (11:22 PM 08/20)

Talega Ridge: 60 MPH (11:22 PM 08/20)

Rockwood (SDGE): 58 MPH (12:20 PM 08/20)

Otay Mountain (SDGE): 57 MPH (12:20 PM 08/20)

Santa Teresa Valley (SDGE): 57 MPH (11:30 AM 08/20)

Alpine RAWS: 55 MPH (9:52 AM 08/20)

East Willows (SDGE): 54 MPH (11:30 AM 08/20)

Mt Woodson: 54 MPH (9:50 PM 08/20)

Otay Mountain RAWS: 54 MPH (1:14 PM 08/20)

Anderson Valley (SDGE): 53 MPH (11:30 AM 08/20)

Thundernut: 53 MPH (12:20 PM 08/20)

Fallbrook RAWS: 52 MPH (10:22 PM 08/20)

San Miguel: 52 MPH (6:27 PM 08/20)

Coronado Hills: 52 MPH (10:08 PM 08/20)

North Potrero (SDGE): 52 MPH (10:50 AM 08/20)

Skye Valley: 51 MPH (9:00 AM 08/20)

Escondido (SDGE): 50 MPH (12:00 PM 08/20)

Potrero (SDGE): 50 MPH (10:30 AM 08/20).

Wider weather episode

Tropical Storm Hilary made landfall across northern Baja California on August 20, and moved through Southern California that afternoon and evening. Torrential rainfall occurred across mountain and desert communities, resulting in catastrophic flash flooding and debris flows, damaged railways and bridges, and the closing of major interstates including I-8 in San Diego County and I-10 in Riverside County. Widespread tropical-storm force winds were recorded across much of Southern California.

Source: NOAA Storm Events Database, event_id 1129866. Narrative written by the NWS forecast office that issued the report.