Shortly before 6 a.m., National Weather Service Doppler radar spotted ``very heavy rain showers'' that could lead to minor flooding in Carlsbad, Chula Vista, El Cajon, Encinitas, Imperial Beach, La Mesa, National City,
Oceanside and Poway. An urban and small stream flood advisory for poor drainage areas will remain in effect until 10 a.m.
``Additional rainfall of one quarter to one half in is expected over the area this morning,'' according to the weather service. ``This additional amount of rain will make minor flooding a concern.''
The storm also caused mountain snow levels to drop to around 5,000 feet this morning, but they are expected to rise later in the day. Up to 5 inches of snow could accumulate in the highest elevations. Winds of 20 to 30 miles per hour are also expected in the mountains, along with gusts to 45 mph.
A winter weather advisory for mountain areas with altitudes higher than 5,000 feet is set to expire at 2 p.m. Drivers on mountain roads were urged to use caution because ``brief periods of heavy snow, strong winds and fog will reduce visibilities to a quarter-mile or less at times.''
Elsewhere in the county, rain was falling and forecasters predicted a slight chance of thunderstorms as the storm impacts the region for a second day.
Less than a half an inch of rain had accumulated in the majority of San Diego County as of 5 a.m.. But automated gauges collected .62 inches of rain at the Henshaw Dam, .56 inches in Rancho Bernardo and .52 inches in Warner Springs, according to the weather service.
Since early Wednesday, wind gusts of 56 miles per hour were recorded at Mountain Springs Grade, 54 mph in Harrison Park, 52 mph on Volcan Mountain and 50 mph in Julian. In the deserts, gusts of 49 mph were recorded in Ocotillo Wells, 45 mph in Borrego Springs and 37 mph at the Narrows.
A wind advisory for the deserts will remain in effect 4 a.m. Saturday.
Areas of west winds of 20 to 30 mph with gusts that could reach 60 mph are expected to continue throughout the advisory period.
Forecasters said the wind may lead to hazardous driving conditions, especially for motorists in high-profile vehicles. Visibility along some desert roadways could also be reduced by blowing sand and dust.