UPDATE (10:49 p.m.): Doppler radar has indicated areas of moderate to heavy rain across all of Santa Barbara County. Rainfall rates between 0.25 and 0.50 inches were common across the advisory area.
However, local rates between 0.50 and 0.70 inches per hour have been observed across the Santa Ynez range.
Rainfall at these rates will continue through the early morning hours Monday.
The highest rainfall rates are expected through 2 a.m. Monday morning across the Santa Barbara South Coast and Santa Ynez range, when rainfall rates between 0.50 and 0.75 inches per hour will be common.
There is still a slight chance of thunderstorms during this time, which could locally produce rates in excess of 0.75 inches per hour.
The advisory expires at 4:30 a.m. Monday.
ORIGINAL STORY: The National Weather Service has issued an Urban And Small Stream Flood Advisory for Santa Barbara and San Luis Obispo Counties until 10:45 p.m.
Doppler radar indicated rainfall coverage and intensity increasing across the Central Coast, with rainfall rates ranging between 0.25 and 0.33 inches across both Santa Barbara and San Luis Obispo Counties.
Localized rates of 0.33 and 0.65 inches per hour have been observed across the Western portions of the Santa Ynez mountain range.
Rainfall rates are expected to peak this evening, where there will also be a slight chance of thunderstorms. During this time, rainfall rates between 0.50 and 0.75 inches per hour will become more common across south and southwest facing slopes.
Roadway flooding is expected to become more widespread across San Luis Obispo and Santa Barbara Counties through the evening hours.
There will also be the threat of rock and mudslides, especially canyon and mountain roadways. The Cave Burn area could also see localized and shallow mud and debris flows this evening.
Excessive runoff from heavy rainfall will cause flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other drainage areas and low lying spots.
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles.
Some locations that could experience flooding include Santa Maria, Santa Barbara, Montecito, San luis obispo, Lompoc, Paso Robles, Morro Bay, Pismo Beach, Santa Ynez, Atascadero, Arroyo Grande, Nipomo, Carpinteria,Cambria, Solvang, Vandenberg Air Force Base, Orcutt, Los Alamos, and the Cave Fire burn area.