Updated

A storm expected to bring much-needed rain to California starting Monday could be a double-edged sword for residents living near hillsides made bare by the ferocious flames from the record-setting wildfires last month.

The Santa Barbara Office of Emergency Management issued mandatory evacuations beginning at noon Monday for the areas below the Thomas, Whittier, Sherpa and Rey fire burn areas due to the upcoming storms, which could cause floods and mudslides.

The mandatory evacuation order covers unincorporated parts of Santa Barbara County, Montecito, Summerland, and Carpinteria including all areas North of Highway 192, East of Cold Springs Road, and West of the Highway 150 to the county line.

Further south, county officials issued a voluntary evacuation warning all areas south of Highway 192 to the Pacific Ocean and areas East of Hot Springs Road and Olive Mill Road to Highway 150/the county line.

"People in these areas should stay alert to changing conditions and be prepared to leave immediately at your own discretion if the situation worsens,"  Santa Barbara County said in a statement.

The National Weather Service said up to six inches of rain could fall starting Monday in parts of Santa Barbara and Ventura counties, where the Thomas fire has burned for more than a month, scorching more than 440 square miles of trees and brush. About an inch is forecast for downtown Los Angeles, the most in 10 months, according to FOX11.

SOUTHERN CALIFORNIA WILDFIRES TRIGGER MASS DESTRUCTION, HURTING FAMILIES, ECONOMY

In Montecito, where the Thomas Fire got dangerously close, residents spent Sunday filling sandbags ahead of the storm.

California Sand Bags

Officials handed out sandbags to residents near areas affected by the recent wildfires in Southern California. (FOX 11)

"People keep saying when the water comes down, it's not going to be water, it's when the mud comes down," resident John Mooy told KEYT. "There is baked earth above us, thousands of acres of baked earth."

Besides heavy rain, snow is expected as low as 4,000 feet early Tuesday, which could make for treacherous driving conditions in mountain areas while wind gusts may approach 60 mph along the coast.

"I think it's important because with fire we had some warning at least," Montecito resident Stacy McCrory told KEYT. "Floods can happen very quickly so I think people should take it seriously."

The Associated Press contributed to this report.