The latest in a week-long series of El Nino-driven storms continued to soak San Diego County early Thursday and the torrential rainfall, strong wind and hail could wreak havoc on morning commuters.
In a four-day period ending at 4:05 a.m. Thursday, automated gauges collected 5.72 inches of rain on Mt. Woodson; 4.85 inches on Palomar Mountain; 4.69 inches in Julian; 4.05 inches in Ramona; 3.84 inches in Poway; 3.79 inches in Oak Grove; 3.18 inches in Descanso; 3.06 inches in Alpine; and 3.05 inches in Rancho Bernardo.
Numerous other locales reported less than 3 inches of rain, including Valley Center with 2.81 inches of rain, Santee with 2.76 inches, Lindbergh Field with 2.44 inches and 1.91 inches in Borrego Springs, according to preliminary data from the National Weather Service.
Around 4 a.m. Thursday, Doppler radar picked up a line of strong thunderstorms from near Solana Beach east to Poway, Ramona and the San Diego Country Estates. Weather service meteorologists said they were moving east at 35 miles per hour.
Forecasters said cloud-to-ground lightning, half-inch hail and winds in excess of 40 mph would be possible during the latest storm and could affect Alpine, Carlsbad, Del Mar, Encinitas, Escondido, Julian, Mount Laguna, Poway, San Marcos, Santee, Solana Beach, Ramona and Rancho Santa Fe.
“Torrential rainfall is also occurring with this storm and may lead to flash flooding,” according to the weather service. “Do not drive your vehicle through flooded roadways.”
A weather service winter storm warning for the mountains above 4,500 feet will extend until 10 p.m. Thursday. A flood warning for the San Diego River in Mission Valley will expire this morning, and a flash flood warning for the beaches, valleys and mountains will end at noon.
Flooding may also be possible along the coast, as a large northwest swell peaks with occasional surf sets of 10 to 14 feet. A high surf warning is set to end at 10 p.m. Friday.
“This kind of surf is capable of damaging coastal structures as well as producing coastal flooding and beach erosion,” according to the weather service.
Forecasters said rain showers and isolated thunderstorms would continue to deluge some locales as the storm moved through the region this morning but gradually become less intense Thursday night through Friday.
Forecasters said that although the rainfall Thursday would be more localized and brief than Tuesday and Wednesday, local flash flooding would be possible through late morning.
“Periods of heavy rain will continue a threat of flash flooding, mud slides and debris flows to recently burned areas, as well as steep and/or unstable terrain below the snow level,” according to the weather service. “Urban flooding, and minor flooding of small streams and low water crossings will also be possible.”
The weather service said an additional 6 to 10 inches of snow could accumulate in the mountains through the evening. Southwest winds of 20 to 30 miles per hour with gusts up to 45 mph will also be possible through Thursday night.
But the heavy mountain snow is soon expected to lighten up, according to the weather service. Forecasters said snow would continue Friday, but showers would be scattered and light.
Blowing snow and fog could lead to hazardous driving conditions. Travelers on mountain roads were advised to carry tire chains, extra clothing and food.
However, more rain will be possible over the upcoming weekend and again next week, according to the weather service.
— City News Service
