UPDATE (2:07 p.m.) - The Santa Barbara County Fire Department says forward progress of the fire was stopped at three acres.
A helicopter was assisting crews on the ground.
No injuries were reported and no structures threatened.
The cause is under investigation and traffic remains impacted in the area.
(2 p.m.) - Firefighters were responding to a brush fire that broke out Tuesday afternoon off Highway 101 near Buellton.
It was first reported at about 1:20 p.m. along the southbound lanes, south of the Highway 154 offramp, near Jonata Park Road.
Santa Barbara County Sheriff's officials said drivers should try to avoid the area as traffic was being impacted.
As of 1:45 p.m., the California Highway Patrol was reporting that the southbound slow lane was closed but all northbound lanes were open to traffic.
This story is developing and will be updated.