PROJECT ALERT NOTICE (CA) new storm causing additional high flows/flooding

Date: Mon, 09 Jan 2023 15:36:48 EST

Summary: new storm causing additional high flows/flooding

A new storm with strong winds and additional rainfall affected northern CA over the last 24 hours and is expected to continue through tomorrow. A series of storms from Dec 31 to today have killed 12 people. This morning, almost 140,000 homes and businesses are reported to be without power.

The National Weather Service issued numerous flood and flash flood advisories as well as high wind warnings throughout many areas of the state. Over the last 24 hours, 1 to 2 inches of precipitation has been widespread throughout much of northern CA on top of high precipitation totals from the previous week and a half; 3 to 5 inches was reported north of Redding, east of Chico, around the Ukiah and Santa Rosa area, the slopes west of Mammoth Lakes, and around Santa Cruz; many coastal areas from Salinas to Santa Barbara received in excess of 5 inches.

Russian, Navarro, Carmel, Ventura Rivers are currently in flood stage, and 5 others in the hardest hit areas are expected to reach flood stage. 12 forecast points are above monitoring stage with 20 others expected to reach monitoring stage soon.

Last night, several areas near San Francisco and Sacramento were evacuated in advance of the predicted high rainfall. Parts of Santa Barbara are under evacuation orders.

Today, the California Water Science Center sent 17 teams of 34 people from the Redding, Redlands, Santa Cruz, Santa Maria, and Ukiah Field offices to measure high flows at their streamgages. The Russian, Navarro, San Lorenzo, and many coastal basins are currently at high flows. Indirects measurements are likely needed in the Santa Maria to Santa Barbara area due to accessibility issues for the high flows.

6 gages are not transmitting. One new gage (11147098) is about to be overtopped, and a RDG is being mobilized to collect data.