UPDATE (5:08 p.m.): The National Weather Service has issued a Flash Flood Warning for South Central San Luis Obispo County until 6:45 p.m.
Flash Flood Warning continues for San Luis Obispo CA, Arroyo Grande CA, Nipomo CA until 6:45 PM PDT pic.twitter.com/m8WGXbwxem— NWS Los Angeles (@NWSLosAngeles) March 11, 2020
The agency's Doppler radar indicated a line of strong and nearly stationary thunderstorms producing very heavy rain.
Rainfall rates up to 1.1 inches per hour have been observed in the past 30 minutes in Oceano and Pismo Beach, with potentials for flash flooding.
Potential impacts include flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other drainage and low lying areas.
Some locations that could experience flooding include San Luis Obispo, Pismo Beach, Arroyo Grande, Nipomo, Grover Beach, Oceano, Avila Beach, Shell Beach, Baywood-Los Osos and Highways 1 and 101.
ORIGINAL STORY: The National Weather Service has issued a flood advisory for both Santa Barbara and San Luis Obispo Counties.
At 214 pm, significant weather advisory issued for central SLO county. Line of thunderstorms will be capable of producing dime size hail, wind gusts to 50 mph, and very heavy downpours. #SLOWeather #cawx #Socal pic.twitter.com/yaWy3cyHcP— NWS Los Angeles (@NWSLosAngeles) March 10, 2020
The Doppler radar has indicated areas of moderate to heavy showers, with isolated thunderstorms across most of Santa Barbara County and Southern San Luis Obispo County.
The storms are moving north at 20-25 mph and are expected to cover much of San Luis Obispo County during the next hour.
Rainfall rates up to .70" per hour have been observed in the Santa Ynez Mountains as well as rates up to .35" in 15 minutes.
There is still potential for isolated rates up to one inch per hour along with thunderstorm activity.
Rainfall rates of this intensity will likely cause roadway flooding as well as potentials for minor mud and debris flows in the recent Cave Fire burn area, according to the National Weather Service.
Some locations that could experience flooding include: Santa Maria, Santa Barbara, San Luis Obispo, Lompoc, Morro Bay, Pismo Beach, Montecito, Santa Ynez, Point Conception, Arroyo Grande, Nipomo, Carpinteria, Solvang, Vandenberg Air Force Base, Los Alamos and Refugio State Beach.
The advisory expires at 4:30 p.m.