Active AlertsNorthern San Joaquin Valley

A series of warm atmospheric rivers will bring moderate to heavy rain to the Valley, foothills, and mountains the week of Christmas. The prolonged period of rain will bring the risk of flooding to the Sacramento Valley, northern San Joaquin Valley, northern Sierra Nevada and adjacent foothills, as well as the Coastal Range.
What: Flooding caused by excessive rainfall continues to be possible.
Where: A portion of northern California, including the following areas, Carquinez Strait and Delta, Sacramento Valley, Motherlode, Mountains Southwestern Shasta County to Western Colusa County, Northeast Foothills, Northern San Joaquin Valley, and Shasta Lake Area / Northern Shasta County .
When: Through Friday afternoon.
Impacts: Excessive runoff will result in rises along area rivers, creeks, streams. Small streams and creeks may rise out of their banks. Flooding may occur in low-lying, poor drainage, and urban areas. Mudslides and rockslides may occur in mountain and foothill areas.
Additional Details: - Periods of moderate to heavy rain are forecast the week of Christmas. Debris flows are not expected over recent burn scars in northern California, but do anticipate enhanced runoff in/below scars. - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.