Heavy Rain Risks Flooding, May Top Off California Reservoirs

California is facing days of heavy rainfall that could help its drought battle by replenishing reservoirs while risking flooding in much of the state. An atmospheric river of moisture is headed from the Pacific Ocean toward California and other Western states, AccuWeather reports. The results could include rainfall of 8 to 16 inches in a band of Northern and Central California, with 20 inches possible in some areas, through the holiday weekend. The biggest downpours are predicted for Friday night to Saturday night. Heavy snow in the mountains is another possibility.

Warm air is expected to arrive early in the storm, increasing the chances of avalanches in the mountains. And melting snow in the mountains could lead to rapid flooding in rivers running from the Sierra Nevada to the Sacramento and San Joaquin valleys. The first storm landed Tuesday, per the Los Angeles Times. The state lists Northern California's Oroville, Folsom and Shasta reservoirs at around one-third of capacity. "It is possible that this single storm brings some reservoirs close to full capacity," said AccuWeather meteorologist William Clark, cautioning that "where there are no dams or flood control measures, unprotected areas along some of the rivers can quickly take on water in this situation." (More California stories.)