Heavy Snow in Riverside County Mountains, California

A series of storm systems in close succession brought very heavy snowfall to the Riverside County Mountains, with the first occurring along a cold front late on January 14 into the morning hours of January 15, with the second system close on its heels, producing additional snowfall late on January 15 to early on January 17. The first system produced up to 11 inches of snow neat Mt San Jacinto at 8400 feet at the Long Valley Ranger Station at the top of the Palm Springs Tram. The second system had lower snow levels, with 4 to 6 inches reported as low as 5700 feet.

The last in a series of atmospheric rivers impact Southern California January 14-16. Widespread heavy rainfall occurred in back-to-back two waves, with the first occurring the afternoon of January 14 into the early morning hours on January 15, and the second occurring the night of January 15 through January 16.

The first storm system resulted in numerous reports of flooding in San Diego County, Orange County and Riverside County and high-elevation snow in the mountains of San Bernardino and Riverside Counties. Rainfall amounts generally ranged from 1 to 2 inches for the coast, 1 to 2.5 inches in the valleys, 2 to 5 inches in the mountains and up to one-half of an inch in the deserts.

The second, colder system again produced widespread moderate to heavy rainfall, with the heaviest rain focusing on San Diego County. Many reports of flooding were received in San Diego County, with numerous swiftwater rescues performed, with 19 alone by San Diego City. The San Diego River overflowed, with the highest impacts reported in Fashion Valley on January 16, with a dozen swiftwater rescues performed before dawn. Nearby areas in Hotel Circle were evacuated due to the threat of flooding.

Impressive precipitation amounts were reported from the two back-to-back system, with 2 to 4 inches of rain received at the coast, 2 to 5 inches for the inland valley and 3 to 8+ inches for the mountains.