Los Angeles, CA – Residents of Southern California and parts of Arizona should prepare for possible flash flooding Thursday as a band of heavy rainfall moves into the region.
According to the National Weather Service’s Weather Prediction Center, a “slight risk” of excessive rainfall has been issued for September 18, with the greatest impacts expected across Southern California and western Arizona. Areas near burn scars, dry washes, and mountainous terrain are most vulnerable to dangerous runoff and flooding.
The Weather Service advises that scattered flash flooding could develop quickly, especially during periods of intense rainfall. Motorists and residents are urged to avoid low-lying areas, monitor local forecasts, and prepare for travel delays.
Officials caution that flash floods are among the deadliest weather hazards, often striking with little warning. The agency reminds drivers to never attempt to cross flooded roads, using the phrase: “Turn Around, Don’t Drown.”
While the flood threat is considered “slight,” meaning at least a 15% chance of flash flooding, forecasters stress the need for awareness. Even localized flooding can disrupt commutes, damage property, and pose risks to anyone caught in rapidly rising water.
The alert is in effect throughout Thursday, Sept. 18, as showers and thunderstorms are expected to develop during the afternoon and evening hours. Travelers and residents are encouraged to have multiple ways to receive alerts, including weather radios and mobile notifications.
This week’s rainfall comes at a time when much of the Southwest remains vulnerable due to recent dry conditions, which can increase runoff risk. Residents in Los Angeles, San Diego, Riverside, and Phoenix areas should remain especially cautious.
