Forecaster are predicting widespread rain over San Diego County Thursday, the National Weather Service said.
Scattered showers and areas of drizzle are expected throughout Thursday with a 20% chance of rain that night.
Periods of rain and much cooler conditions are expected through Friday. Friday's high temperatures are expected to be in the low 60s near the coast, the low 70s in the valleys, 77 to 87 in the mountains and up to 104 in the desert, according to the NWS.
Overnight lows were expected to be mostly in the 40s, and in the 50s in the desert.
Rainfall totals were estimated to range from about one quarter-inch to one half-inch in the coastal areas and valleys, one-half to 1 inch in the mountains and only a few hundredths of an inch in the deserts.
Snow levels could lower to 5,000 to 6,000 feet into Thursday and several inches of accumulated snow were expected above 6,000 feet.
Cooler conditions are expected for the remainder of the week. Thursday is likely be the coolest day, with daytime temperatures 5-10 degrees below seasonal averages in the coastal areas and as much as 15-20 degrees below seasonal averages farther inland.
Precipitation was likely to end Friday afternoon as the trough axis moves east and the atmosphere stabilizes.
