The first cold front of the autumn season reached San Diego Wednesday night, bringing storm clouds and light sprinkles that were expected to develop into mountain thunderstorms and heavier rain on Thursday.
The National Weather Service issued a flash flood warning until 6:45 p.m. Thursday for east and central San Diego County.
Areas that could experience flooding include Mount Laguna, Ocotillo Wells, Agua Caliente, Canebrake, Fish Creek Wash, Highway S2 between Shelter Valley and Agua Caliente, Highway S2 between Agua Caliente and Canebrake, Highway S2 at Vallecito Creek Road, and Highway S2 between Canebrake and the Imperial County Line.
A severe thunderstorm warning was also issued until 5 p.m. for southeastern San Diego County. The NWS said a thunderstorm was moving south over Ocotillo Wells near Highway 78 by Borrego Springs Road.
Rain started falling in San Diego's East County communities of El Cajon, La Mesa and Spring Valley just before 11 p.m., NBC 7's First Alert Doppler 7 showed.
By 3:30 a.m., the National Weather Service recorded more than a half-inch of precipitation on Mount Laguna and Pine Valley.
Light, spotty showers continued to bring sprinkles mostly to coastal communities overnight but by mid-morning, clouds were expected to part to sun.
The storm would then shift focus to the mountains and deserts. The NWS said any storms that develop, likely during the afternoon and late evening, could produce heavy rain and lightning.
The weather change comes after after hot, dry and breezy weather set the table for two wildfires that forced evacuations in San Diego's East County this week.
Spotty showers could linger over the county through Saturday with the most significant precipitation expected in the mountains and deserts, Parveen said.
Mostly, the cold front was dropping temperatures across the county.
Temperatures Saturday were expected to be in the low-70s along the coast, in the mid-70s inland, in the low-70s for the mountains and in the low-90s for the deserts.Follow forecasts specific to your zip code here.