Flash flood warning issued for parts of SLO County as rainstorm sweeps region

Parts of San Luis Obispo County were under a flash flood warning Saturday morning as a rainstorm swept across the Central Coast.

“Some locations that will experience flash flooding include north of Cambria to San Simeon including Hearst Castle and adjacent foothills,” the National Weather Service said in its warning, issued at 9:31 a.m.

The flash flood warning was set to remain in place until 11:30 a.m. Saturday, the NWS said.

According to the agency, 1 to 2 inches of rain had fallen in the area as of Saturday morning, with an additional 1 to 2 inches of rainfall expected.

“Flash flooding is ongoing or expected to begin shortly,” the agency said, impacting “small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas.”

The flash flood warning for northwest San Luis Obispo County expired around 11:10 a.m.

“The axis of moderate to locally heavy rain bands has shifted southward between Cambria and Morro Bay, where a flood advisory remains in effect,” the agency said in a tweet.

The flood advisory was later lifted as well.

National Weather Service: Flood advisory for Paso Robles, Morro Bay

Also on Saturday morning, the Weather Service issued a flood advisory for several SLO County communities.

“Doppler radar indicated bands of moderate to heavy rain moving into coastal and foothill areas of northern San Luis Obispo County,” the Weather Service said in the advisory, issued at 8:45 a.m. “This on top of the moderate to heavy rainfall that fell in the past six hours will likely result in some urban and small stream flooding.”

The agency predicted between 0.33 and 0.75 inches of rain per hour in the affected area.

Rainfall rates in some spots could approach an inch per hour, the Weather Service said, “mainly in the foothills and near thunderstorms.”

Areas that could experience flooding include Atascadero, Cambria, Cayucos, Hearst Castle, Lake Nacimiento, Los Osos, Morro Bay, Paso Robles, Point Piedras Blancas, Santa Margarita and Templeton, as well as Highway 101 over the Cuesta Grade, the NWS said.

The flood advisory will be in place until 12:30 p.m. Saturday, the agency said.

The Weather Service warned people to be cautious when driving in heavy rain.

“Turn around, don`t drown when encountering flooded roads,” the agency warned, noting that most flood deaths occur involve people trapped in vehicles.