(NWS ) San Diego County faces a third straight night of heavy snow in the mountains and sporadic and intense rain elsewhere from a plodding storm out of the Gulf of Alaska that has brought unusually cold air to Southern California. The National Weather Service says that fresh rounds of rain cells will move ashore Thursday afternoon and intensify Thursday night and last into Friday morning. The cells could drop 0.30 inches to 0.40 inches of rain, lifting the three-day precipitation totals to more than one inch in many coastal cities and 2 inches inland. The incoming cells also could spark lightning and hail. The temperature at 20,000 feet is about minus 24 degrees Fahrenheit, which is making the atmosphere highly unstable.