PROJECT ALERT NOTICE (CA) intense rainfall in Santa Barbara to Oxnard area

Date: Fri, 22 Dec 2023 15:00:37 EST

Summary: USGS field crews measuring streamflow during and after intense rainfall in the Santa Barbara to Oxnard areas

Yesterday, intense thunderstorms in Santa Barbara and surrounding areas brought intense rainfall, possibly record intensity in some areas, that caused localized flooding. Over the last 48 hours, most of the area between Santa Barbara and Ventura received about 4 inches, with Santa Barbara and nearby areas receiving 5 inches of rainfall, with a peak of 10 inches in the mountains north of Carpentaria. Near Santa Barbara, there were unofficial reports of over 2 inches in one hour yesterday. The National Weather Service issued several tornado warnings.

While homes and roads were flooded and caused evacuations, the USGS streamgages reached elevated flows but did not reach flood levels, likely due to dry conditions prior to this event. The storm did not damage any streamgages, and no peaks of record were observed.

Field crews were able to measure elevated flows yesterday at several sites altered during the 2023 Water Year storms, and they will make recession measurements today. Of note, a high flow measurement at the Atascadero Creek nr Goleta gage found the rating was over computing discharge, which was corrected provisionally pending additional measurements.