Northern California is experiencing its wettest winter on record, with reservoirs full, the ground saturated, and many of the rivers at or near flood stage.
Oroville Dam, northeast of Sacramento, is on the brink of failure and downstream residents have been warned to evacuate. Water is being released through the emergency spillway in a desperate attempt to save the dam.
During the past two weeks, immense amounts of precipitation has fallen over the West Coast (see image), with some locations in the Sierra and coastal mountains getting more than 20 inches of water.
Considering the last 60 days, large sections of California, Nevada, Utah, and southern Oregon have received 200-400% of normal precipitation, with limited areas exceeding 400% of normal. Generally, Washington State is slightly drier than normal.
Folks, it is not over yet. Although a ridge of high pressure temporarily has dried things out the last few days, the fire hose of rain will be returning on Wednesday.
Here is the forecast precipitation total for the next 9-days from the U.S. GFS model. Nearly all of the Cascades, Sierras, and coastal mountains will get 5-10 inches of additional precipitation. This includes the last hold-out from serious wetting, the mountains behind Santa Barbara.
The forecast for nearly the identical period from the European Center model shows a similar story. Very wet conditions along the entire West Coast.
A number of rivers are now at flood stage in California (red dots on map below from the California/Nevada river forecast center) and they will be pushed higher during the next week.
The atmospheric river that will approach the Northwest on Wednesday will be a strong one (see map, blue colors indicate very large water contents), and will then head towards California. And more atmospheric rivers are to follow.