San Diego is all too familiar with atmospheric rivers.
The monsoon 12th Atmospheric River began to pour heavy rain over northern San Diego County around midnight Tuesday, and the entire county was expected to be covered by 3 or 4 a.m.
“It’s going to be a mess as we approach this morning hour,” NBC 7 meteorologist Dagmar Midcap said.
Midcap said the atmospheric river has merged with a cold Pacific northwest storm, bringing mountain snow and strong winds in addition to heavy rainfall.
The following hours and warnings were in effect as of Tuesday morning, according to the National Weather Service:
- Flood watch: From 5 am Tuesday to Wednesday evening in coastal areas.
- Excessive runoff can flood rivers, streams, creeks, and flood-prone areas. The NWS is predicting 0.6 inches of rain per hour in some areas.
- Strong wind warning: From 6:00 to 22:00 Tuesday in coastal areas.
- Wind force is expected from 25 to 35 m/s, gusts from 45 to 55 m/s.
- Airport weather alert: 5:00 to 23:00 Tuesday at SAN
- The NWS issues this alert when weather conditions may affect airport operations.
- High Surf Recommendations: from 2:00 Wednesday to 21:00 Thursday on the coast
- Waves from 4 to 8 feet, setting up to 12 feet.
Although this storm arrives on the first day of spring, it will still be a winter storm because winter rainfall will fall in the mountains by the end of it, according to NBC 7’s Chandel Menezes.
Anticipating problems at flood-prone river crossings, the City of San Diego proactively several roads closed in the Mission Valley area (the city did not say when the closure would be lifted):
- Camino de la Reina on the Camino de la Siesta (to the west).
- Camino de la Reina west of Avenida del Río (heading east).
- San Diego Mission Road between Fairmount and Caminito Yucatán (eastbound and westbound).
- Qualcomm Way and Rio San Diego Drive (southbound only).
- Mission Center Road between Hazard Center Drive and Camino De La Reina (heading north).
- Ward Road in Camino del Río N (heading south).
- Camino Del Este between Station Village Drive and Camino De La Reina (northbound).
- Camino Del Este between Station Village Drive and Camino De La Reina (southbound).
Atmospheric rivers are long, powerful sections of the atmosphere that carry a lot of water from tropical regions near the earth’s equator to the poles. The first raindrops produced by the system fell on Sunday night. By 4:45 p.m. Monday, the NWS measured the following 24-hour precipitation totals:
- San Diego County coast
- Encinitas: 0.36 inches
- Ocean side: 0.34 inch
- El Camino del Norte: 0.26 inches
- San Onofre: 0.19″
- Fallbrook: 0.35″
- Rainbow: 0.34 inch
- Lake Miramar: 0.34 inches
- Skyline Ranch: 0.28″
- Palomar: 1.15 inches
- Birch Hill: 0.92 inches
- Mesa Grande: 0.66 inches
- Descanso: 0.55″
By Tuesday evening, residents at 4,000 to 5,000 feet could see 3 to 10 inches of snow.
San Diego Gas & Electric said it is increasing the number of crews that can deal with any power outages that occur during a hurricane. The agency encourages clients to have a plan in case of business interruptions. They also warn residents to stay away from any power lines that are down and report them by calling 911 or SDG&E at (800) 411-7343.
Cal Fire’s Swift Water Rescue teams are also on standby to respond to San Diegan residents stranded in the flood zone.
Dave Summers of NBC 7 spoke with the Cal Fire captain about water rescue teams preparing for the next storm in San Diego.
Weeks of downpours that made sunny San Diego look more like Seattle have left the ground saturated, meaning new rain won’t be absorbed.
“…most of it will be thrown into our low-lying areas,” said California Fire Department Captain Michael Cornett.
Flooded waterways are full of debris and dangerous to anyone caught in the stream.
“We don’t know what’s going downstream — if there’s more water, if it’s a flash flood situation, we don’t know if there’s a big log or a tree branch,” Cornett explained.
Cornette wants drivers to remember that it only takes 6 inches of water to move a car, and if you find yourself in a current strong enough to move your car, it will likely sweep you away if you get out of the car.
Cal Fire will have two rescue teams on standby until the threat abates.