High Wind — Imperial Valley, California

2023-08-20 · Imperial Valley, California

Event narrative

Power poles were reported down near Evan Hewes Highway. No injuries were reported.

Wider weather episode

Tropical Storm Hilary brought abundant moisture along with strong winds to southern California on the 20th. In fact, Tropical Storm Warnings were issued for the first time in history along the southern California coast. On the 19th, a trough near the southern California coast promoted deep southerly flow that allowed deeper moisture to advect into the Southwest ahead of Hilary. Combined with jet dynamics, showers and thunderstorms developed during the early morning hours on the 19th, leading to an isolated instance of flash flooding in southeast California. Going into the 20th, very anomalous moisture accompanied Hilary with PWATs across southeast California climbing upwards of 2-2.5 and IVT values in excess of 15 normalized standard deviations from average. Thus, flash flooding was the primary impact across southern California with a very rare high risk of excessive rainfall being issued by WPC for part of the area. Rainfall totals across southeast California were as high as 2-3, while most areas across Imperial County and eastern Riverside County generally measured around 1.50 or less. However, much heavier rainfall amounts were observed closer to the southern California coast. In addition to flash flooding impacts, several instances of damaging winds occurred as strong low level winds upwards of 50-60 knots at 850 mb and 925 mb mixed to the surface in some cases. Several communities around the Salton Sea were under a voluntary evacuation order as a precaution for any potential impacts stemming from flash flooding and strong winds. Multiple reports of flooding impacts and wind damage primarily across Imperial County resulted from this event. No injuries were reported.

Source: NOAA Storm Events Database, event_id 1132788. Narrative written by the NWS forecast office that issued the report.