Intense rainfall expected on March 20 triggered a new round of evacuation orders in Santa Barbara and Ventura counties for residents in areas near the Thomas, Sherpa, Vista and Whittier fire burn scars.

The storm is expected to be the strongest of the season, said Mark Jackson, a meteorologist with the National Weather Service. Rainfall rates could reach up to three quarters of an inch per hour, well above the half-inch threshold that could cause debris flows where vegetation burned or structures were destroyed in the fires.

In all, around 7,400 residences are affected and 17,000 to 18,000 people are expected to be displaced in Santa Barbara County. More information and an interactive map of the evacuation zones can be found at www.readysbc.org.

Mandatory evacuation orders were also issued for parts of Ventura County, including Matilija Canyon, North Fork, parts of the Vista fire burn area, Nye Road and La Conchita through March 22. Casitas Pass Road, Ojai Road near Thomas Aquinas College Road, East Ojai and Norway Tract were also under voluntary evacuation. More information can be found at www.vcemergency.com.

Cumulatively, the foothill and mountain areas are expected to receive five to 10 inches of rain, which is significantly stronger than the storm Jan. 9 that killed 21 people and damaged or destroyed around 400 buildings in the Montecito, Summerland and Carpinteria areas.

Evacuees should be out of the evacuation zones by noon, officials said at a public meeting in Santa Barbara March 19, and the warnings recommended that residents near the Alamo burn area also evacuate.

“It’s not about the amount, it’s about how fast it falls,” Jackson said.

Robert Lewin, director of the Santa Barbara County Office of Emergency Services warned of flooding, mudslides or falling rock in other areas of the county as well, including urban areas.

“This is not the storm to question,” Lewin said, adding that more rain is expected in a three-day period than parts of Santa Barbara County usually gets all year and emphasizing that residents should heed the evacuation orders. “This much rain on a burn area is something even we are not sure of … There is plenty of debris on those mountains. They are locked and loaded.”

Debris basins and channels had been cleared by Flood Control teams ahead of the storm.
An evacuation center is being set up at Ventura College and one will open at noon on March 19 at the Earl Warren Showgrounds in Santa Barbara.

The California Highway Patrol will monitor the storm activity with the goal of keeping Highway 101 open for evacuations, but the traffic artery could close if lives are deemed to be at risk.

The storm is expected to clear by the end of the week on March 22, Jackson said.

• Contact Robert Shutt at rshutt@pacbiztimes.com