Heavy Rain in Orange County, California

Shortly after 0900 PST, the roof of a classroom partially collapsed due to heavy rain. Fourteen people, ages 17 to 50, were taken to the hospital with minor injuries.

A pair of winter storms associated with a vigorous, cold upper-low brought periods of high winds, heavy rain, and snow to the region from late on the 13th through the 17th. The first storm brought rain to the lower elevations and gusty winds and very heavy snow to the mountains and deserts. Blizzard conditions forced the closure of mountain highways while heavy rain caused a debris flow in the Santiago Burn Area. Snowfall accumulations from this first storm measured 31 inches at Big Bear Lake, 30 inches at Running Springs, and 24 inches at Forest Falls. The second storm on the 17th was notable for its significant rains in the low deserts and heavy snowfall in the mountains and high deserts. Heavy rain caused significant flooding in the Tijauna River valley. Surface offshore pressure gradients and mid-level easterly flow brought dry air into the region, resulting in widespread evaporative cooling and snow levels down to the desert floor. The winter storm dumped 20 inches of snow in Pinon Hills, 18 inches of snow in Hesperia, Lucerne Valley, Palomar Mountain, and Julian, 16 inches of snow in Idyllwild, 14 inches in Victorville, and even 4 inches in Shelter Valley. Local snowfall amounts in excess of 2 feet occurred in the San Bernardino Mountains. Total snowfall accumulations at Big Bear Lake for the 5 day period ending on the 17th was an impressive 54 inches.