A powerful overnight storm drenched San Luis Obispo County from Wednesday afternoon to Thursday morning, knocking out power, downing trees and causing multiple water rescues.
“I think it was definitely one of the most intense storms I’ve seen,” PG&E meteorologist John Lindsey said Thursday. It dropped more than an inch and a half of rain in several SLO County locations.
The storm caused hundreds in San Luis Obispo County to lose power and forced multiple road closures due to flooding.
In Paso Robles, River Road was closed to through traffic between the Paso Robles city limits and Wellsona Road from about 8 a.m. until about 3:50 p.m. Thursday, according to the county Public Works Department.
Cholame Valley Road remained closed between Highway 46 and McMillan Canyon Road due to flooding as of Thursday morning, the department said.
Creston Road between Neal Springs Road and South El Pomar Road was closed for about an hour on Thursday morning, the department said.
At about 1 p.m., Cal Fire tweeted that its was working with Caltrans and the San Luis Obispo County Sheriff’s Office to clear storm-related debris near Shandon High School.
On Thursday afternoon, Caltrans announced that its crews found multiple debris slides on Highway 1 between Mud Creek and Deetjen’s Big Sur Inn.
“Caltrans maintenance crews and contractor John Madonna are performing herculean efforts to repair and clear the roadway as quickly as possible,” the agency said in a news release.
The road will be closed until further notice, Caltrans said.
Rescues in San Luis Obispo
The San Luis Obispo Fire Department performed two water rescues in San Luis Obispo Creek early Thursday morning, as well as another rescue on Bishop Peak on Wednesday night, according to interim Fire Chief Keith Aggson.
The first rescue took place at about 9:45 p.m., when firefighters went to Bishop Peak to help a lost hiker. Crews found the hiker near the top of the peak and guided him back down.
It wasn’t clear whether the rescue was storm-related, but Aggson said the hiker “indicated he’d gotten lost and was afraid to try to walk down on his own.”
At about 2:45 a.m. Thursday, San Luis Obispo fire crews received a call from a man who had been stranded on an island in the San Luis Obispo Creek bed near the Bob Jones Trail on Prado Road, Aggson said.
“The water at that time was not only an estimated 8 to 9 feet deep, but was also moving at a pretty rapid rate,” Aggson said.
Since the man was safe and uninjured, and because thick vegetation made it difficult for the crews to reach him, firefighters decided to wait until the water receded, Aggson said. By that point, the rain had stopped.
Once the water level went down at about 5:45 a.m., crews conducted a shallow-water rescue and brought the man safely to high ground.
San Luis Obispo fire crews were called out to a third rescue at about 3:30 a.m. at San Luis Obispo Creek just south of Los Osos Valley Road, Aggson said. Two people were in a tent on an island in the creek bed and couldn’t get to higher ground.
Crews were able to pull them to safety using a rope, Aggson said.
All of the people rescued were uninjured, according to Aggson.
Aggson stressed that people should move to higher ground when heavy rains and storms are in the forecast.
“We encourage anyone in low-lying areas prone to flooding — and the creek more specifically — to evacuate and go to higher ground so they don’t get themselves into a predicament where they need rescuing,” Aggson said. “Safety is always the best decision.”
Heavy rain across the county
Locations around SLO County recorded sizable rain totals, with most falling in the early-morning hours.
Between midnight and about 9 a.m. Thursday, Templeton tallied 1.56 inches of rain, Lindsey said. For the entire storm, the area recorded 2.2 inches.
“Templeton got hammered,” Lindsey said. “They really got some pretty intense rainfall from the storm.”
Shandon, which only received 0.08 inches of rain from Monday through Wednesday, totaled 1.56 inches of rain between about midnight and 9 a.m., Lindsey said.
Santa Margarita recorded 1.64 inches between midnight and 9 a.m., and Nipomo received 1.04 inches during the same time period, Lindsey said.
Arroyo Grande reported 1.01 inches of rain during the storm, according to Lindsey.
At around 9:30 p.m. Wednesday, Cal Poly started seeing the rain kick in, Lindsey said, and by 9 a.m. Thursday, the school had recorded 1.43 inches.
Rocky Butte recorded 0.47 inches in 10 minutes at around midnight, according to the National Weather Service. At about 1:30 a.m. Thursday, sloweather.com in western San Luis Obispo recorded a rainfall rate of 5 inches per hour, Lindsey said.
“This storm affected everybody,” Lindsey said. “Tuesday’s storm produced fair amounts of rain in the northern part of county and on this system, everybody got hit.”
Watches, warnings and what’s next
The National Weather Service issued several advisories and warnings related to the stormy weather. Early Thursday morning, parts of San Luis Obispo and Santa Barbara counties were under a flash-flood warning, which ended at 3 a.m.
A wind advisory was in effect until 9 a.m. Thursday, and a high surf advisory was in effect until 2 p.m.
A high surf warning also took effect at 2 p.m. Thursday and will remain in effect until 9 p.m. Friday, the agency said.
A high surf warning is more severe than an advisory, and generally means that “dangerous battering waves will pound the shoreline,” which causes life-threatening conditions, according to the National Weather Service.
A coastal flood advisory will be in effect from 11 p.m. Thursday to 9 p.m. Friday, according to the National Weather Service.
High tides of 6.5 to 7 feet are expected at 7 a.m. Friday, the agency said, and that “will coincide with the building surf.”
“Minor coastal flooding is possible today, with moderate coastal flooding and significant beach erosion likely on Friday,” the National Weather Service said.
Lindsey said a large swell is expected to arrive between 1 p.m. and 6 p.m. Thursday, and called it “one of the biggest swells I’ve ever seen before.”
“It’ll easily be an 18- to 20-foot swell with an 18- to 20-second period,” Lindsey said. “It’s going to really quickly increase, and I’m scared people will be caught off guard.”
Lindsey emphasized that people should not turn their back on the ocean during rough conditions. The swell is expected to decrease to 13 to 15 feet with a 14- to 16-second period on Friday.
Dry weather is expected later Friday into Saturday.