From the California Weather Blog:
“Despite the arrival of substantial early-season rainfall across the far northern portions of the state in recent weeks, nearly all of California has experienced much drier than normal conditions thus far this fall.
In fact, some of the traditionally wetter parts of northern and central California have missed out on nearly 5-10 inches of liquid precipitation that normally would have fallen by this point in the calendar year–an additional deficit adding to the already enormous one accumulated over California’s driest 3-year period on record, which occurred between late 2011 and late 2014. Much above average temperatures have remained the rule across most of California in recent weeks (driven, in part, by the extremely warm ocean surface temperatures now occurring along the entire West Coast of North America), and a fairly persistent ridging pattern has been in place as well (though it’s not quite as persistent as last year’s now infamous Ridiculously Resilient Ridge). After a 3-year period of exceptional dryness in California–which now exceeds the intensity of any other such period in living memory–prospects for meaningful rainfall and snowfall have been tantalizingly ephemeral as early-season storms have repeatedly failed to live up to their initial expectations. ... “