With the first major rain of the season predicted to hit early next week, Santa Barbara County officials warn the Thomas Fire significantly increased the risk of debris flows, rockfalls and flash flooding.
Speaking outside Carpinteria City Hall on Friday morning, Tom Fayram, the county’s water resources deputy director, said those threats are estimated to be 10 times greater than before the fire.
“It’s a real risk that should be taken seriously,” Fayram said. “It’s critical that property owners and residents are aware of their environment, and understand where they are in relationship to the burn area and flood hazards.”
The U.S. Geological Survey has analyzed the fire-scorched areas to determine its vulnerability to debris flows, mudslides and flash floods, according to Mark Jackson, meteorologist at the National Weather Service in Oxnard.
The county posted an interactive map on its website allowing residents to enter an address to check where they are located in potential post-fire hazard areas from the Thomas, Sherpa and Whittier fires.
Jackson said moderate to heavy rainfall is expected to move through the county Monday night into Tuesday morning.
“The one saving grace in this storm system is that it will move through quickly,” Jackson said. “We are fairly certain on the rainfall amounts, but not as certain on the timing.”
He said the storm could drop an estimated 1-2 inches of rain in areas along the coast and valleys, and some mountain and foothills regions could get up to 4 inches of rain in that period.
Peak rainfall rates are predicted at a half inch to 1 inch per hour, he said, with the potential for thunderstorms through the area.
“When you get that kind for rain rate on a fresh burn area, the water moves right off the surface of the burn area, and it carries anything that’s loose — dirt, rocks or burned timber comes down the hillside,” Jackson said.
Ahead of the storm, Jackson said, south winds remain on track to develop with gusts up to 40 mph on the coast, and “possibly damaging” winds in the mountains and higher elevation.
County officials said the rain will likely impact key roads, including Highway 101.
“Factor that in your planning,” Fayram said.
Rob Lewin, the county’s director of emergency management, said the Thomas Fire burned more than 17 named canyons in the county, and “many unnamed ones.” The Thomas Fire is the state’s largest wildfire on record, scorching 281,893 acres in Ventura and Santa Barbara counties as of Friday.
Lewin stressed the importance for residents and visitors to register for emergency alerts through the county’s Aware and Prepare program.
The county also has information on its Thomas Fire website about storm preparedness and the homeowner’s guide for flood prevention and response.
Lewin said during severe weather events, emergency planning officials can be notified as little as 30 minutes before the rain hits the footprint of a fire.
“Unfortunately, we don’t get a lot of warning with the weather,” Lewin said. “Sometimes we have no notice. Make sure you have a plan and disaster kit ready.”
Sandbags are available for free throughout the county and locations are listed on the county’s website.