Update: 9:45 p.m.
Thunderstorms with strong winds of 50 mph and dime-sized hail are moving across Santa Barbara County. The National Weather Service is also reporting frequent lightning and heavy downpours. A storm cell is also moving through San Luis Obispo.
Update: 7:20 p.m.
A severe thunderstorm warning for south-central San Luis Obispo County and northwestern Santa Barbara County has been extended until 8 p.m., the National Weather Service said.
The NWS was tracking a severe thunderstorm that was seven miles north of Los Alamos and 10 miles southeast of Santa Maria at 7:18 p.m., moving at 35 mph. Radar indicated wind gusts to 70 mph and nickel-sized hail, the Weather Service said, advising residents to expect considerable tree damage and damage to mobile homes, roofs and outbuildings.
Affected areas included Santa Maria, Pismo Beach, Arroyo Grande, Nipomo, Orcutt, Los Alamos, Grover Beach, Guadalupe, Vandenberg Air Force Base, Sisquoc and Oceano.
Update: 6:45 p.m.
The National Weather Service has issued a severe thunderstorm warning for south-central San Luis Obispo County and northwestern Santa Barbara County until 7:15 p.m.
Update, 6:20 p.m.
The National Weather Service has issued a flash flood warning for northeastern Santa Barbara County and southeastern San Luis Obispo County. The warning is in effect until 9 p.m. Additionally, those areas are under a severe thunderstorm warning until 6:45 p.m.
The agency said that shortly after 6 p.m., Doppler radar showed “a cluster of strong thunderstorms” producing heavy rain across that area and flash flooding is expected to begin shortly.
Officials predict 60 mph wind gusts and quarter-size hail, and say people should expect hail damage to vehicles and wind damage to roofs, siding and trees.
A “brief, weak” tornado is also possible as thunderstorms move into those areas, the National Weather Service said.
The agency detected a few severe thunderstorms between Lockwood Valley and Ventucopa just before 6 p.m. The storms were moving northwest at about 40 mph, and radar showed “some rotation” within the storm, suggesting a tornado is possible.
The storm is expected to affect northern Ventura County, southeastern SLO County and northeastern Santa Barbara County, including Highway 33, Highway 166 between Twitchell Dam and the Cuyama Valley and the Carrizo Plain.
A band of storms headed toward the Central Coast on Sunday afternoon prompted the National Weather Service to issue a severe thunderstorm warning and a flash flood watch for areas that include the Alamo Fire and Whittier Fire burn areas.
At about 4:50 p.m., the National Weather Service issued a significant weather advisory for northwestern Santa Barbara County that will remain in effect until 5:45 p.m. The agency said that their Doppler radar was tracking a strong thunderstorm seven miles south of Santa Maria. The storm was moving northwest at 35 mph.
The agency predicted the storm would bring wind gusts of 50 to 55 mph, along with small- to medium-sized hail and “frequent lightning.”
Just before 4:20 p.m., the National Weather Service reported that strong thunderstorms are rapidly heading toward the Alamo Fire burn area, which means flash flooding and debris flows are likely. The agency has issued a flash flood watch for the Alamo and Whitter burn areas that will be in effect until “late tonight.”
An evacuation warning has been issued for residents around the Alamo Fire burn area east of Santa Maria, the Santa Barbara County Office of Emergency Management tweeted at about 4:30 p.m. The agency urged residents to be ready to evacuate or go to higher ground.
About 1 inch of rain per hour could fall during these storms, the National Weather Service said.
The agency also issued a severe thunderstorm warning for southern San Luis Obispo County and part of Santa Barbara County, including Arroyo Grande, Nipomo, Santa Maria and Orcutt. The watch will be in effect until 5 p.m., the agency said.
Strong wind gusts and hail are likely with these storms, the National Weather Service said.
According to PG&E meteorologist John Lindsey, scattered rain showers and thunderstorms could develop from Sunday evening until Monday afternoon. There will also be a chance of thunderstorms over the mountains on Tuesday and Wednesday.