Early-Season Storm Heading to SoCal Prompts Flash-Flood Watches

An early-season storm moving into Southern California Thursday has prompted flash-flood watches for the region.

Lightning is shown over Jurupa Valley on Oct. 23, 2016. (Credit: LoudLabs)

Lightning is shown over Jurupa Valley on Oct. 23, 2016. (Credit: LoudLabs)

Most of the rain is expected Friday morning, but light rain could begin Thursday evening.

A “deep trough of low pressure” off the West Coast is bringing subtropical moisture north into Southern California, with remnant moisture from Hurricane Seymour off Baja California also being pulled north, according to the National Weather Service.

A flash-flood watch is in effect from Thursday afternoon through Friday morning for recent wildfire burn areas in L.A. and Ventura counties.

A flash-flood watch for burn areas of the mountains of San Bernardino County is in effect from late Thursday night Friday afternoon. The area around the Blue Cut Fire, which burned 36,274 after starting in the Cajon Pass Aug. 16, could be affected.

Thunderstorms may trigger mud and debris flows, the weather service warned.