Authorities on alert as winter storm moves toward charred mountains in Santa Barbara County

Authorities are monitoring a winter storm that’s expected to bring rain to fire-ravaged mountains in Santa Barbara County starting Monday evening, possibly giving way to flooding and debris flows.

Residents who live below mountains burned by the Sherpa, Whittier, Thomas and Alamo fires were warned late Sunday to prepare in case they are ordered to evacuate Monday night.

The storm is expected to dump less than a third of an inch of rain through Tuesday afternoon, which on its own wouldn’t be a problem, said Kathy Hoxsie, a meteorologist with the National Weather Service.

But there’s a slight chance of thunderstorms, which could bring additional rain that authorities said could trigger “minor debris flows and flooding” below charred slopes.

“The odds of anything at this point are low, but it’s not zero,” Hoxsie said. “This is going to be a sticky wicket for Santa Barbara.”

Forecasters said rain will be the heaviest in the late morning and early afternoon hours on Tuesday.

County officials advised residents to flee to higher ground if they feel threatened at any point during the storm. They prepared an interactive map that shows which areas are most at risk.

“Do not wait for a notification,” officials said in an advisory issued Sunday night. “If an individual or family has access or functional needs, or has large animals to move, consider leaving well in advance.”

The region is still recovering from the devastating mudslides in Montecito last month that swept away homes and killed more than 20 people.

alene.tchekmedyian@latimes.com

Twitter: @AleneTchek