Atmospheric River Headed Toward San Ramon; Flood Watch Issued

SAN RAMON, CA — The phrase "atmospheric river" is back in the weather forecast for Northern California — the same "conveyer belt of moisture" that drenched the area for three straight weeks from late December to mid-January, according to the National Weather Service.

While scattered showers can be expected throughout the week, the weather service reports that the potent atmospheric river will arrive Thursday and continue through Friday. San Ramon and the entire Bay Area are under an NWS Flood Watch from 1 p.m. Thursday until 9 a.m. Sunday. The heaviest rain is expected to fall Thursday evening into Friday morning.

The storm is coming from the tropics in the Pacific Ocean, with an increasing possibility of several inches of rain. The areas at highest risk of more than 2 inches of rainfall include the North Bay, elevated parts of the peninsula in San Mateo County, southern Monterey County and the Central Valley.

In San Ramon, 1.19 inches of rain are expected to fall over 12 hours Thursday night, though the East Bay can expect as much as three inches. Winds are expected to gust at up to 28 mph. On Friday, another 0.79 inches are expected, with winds of up to 20 mph. There is also a 24 percent of thunderstorms.

Since the moisture is coming from the tropics, the rain could prove to be a threat for the deep Sierra snowpack.

The National Weather Service in Reno cautions residents that snow at 5500 feet or lower is at risk of being melted by the rain.

Local resources

To report clogged storm drains, downed trees, or flooding call 925-973-2800 (M-F, 8:30-5) or the San Ramon Valley 911 Communication Center at 925-973-2779 after hours. Sandbags are available at three locations. Residents and businesses are asked to bring a shovel:

• Athan Downs, Montevideo Drive near San Ramon Valley Blvd.
• Central Park, Alcosta Blvd. adjacent to the San Ramon Community Center
• San Ramon Sports Park, Sherwood Way

A full list of storm preparation tips are available here and at Be Ready SRV, an emergency preparedness collaboration between the Town of Danville, the City of San Ramon, San Ramon Valley Fire Protection District, Contra Costa County, and the San Ramon Valley Unified School District. San Ramon residents can also contact the following numbers:

NON-EMERGENCY

• San Ramon Police: 925-973-2779
• Danville Police: 925-820-2144
• San Ramon Valley Fire Protection District: 925-838-6691

OTHER RESOURCES:

• Contra Costa Animal Services: 925-335-8300
• PG&E: 1-800-743-5000 San Ramon Regional Medical Center: 925-275-9200
• EBMUD: 866-403-2683

— Patch editor Bea Karnes and Bay City News contributed to this report.