This pulse of heavy precipitation is associated with an unusually intense low pressure center moving in from off the Pacific (see surface chart for 4 PM Friday). You don't see a 978 hPa low pressure center very often that far south in the eastern Pacific.
Thursday, February 27, 2014
The West Coast Drought Lessens But Remains Serious in California
The snows of the past week have brought the snow pack in Washington State to near normal (see graphic), and substantial improvements have occurred in Oregon, although they are still dry.
Although substantial precipitation will fall, it will provide only modest relief from the severe drought over California (see graphic) and the latest forecasts suggest that focus of most storms will move northward next week. Oregon has a real chance of moving up to near-normal snow pack before the next few weeks are over.
Posted by Cliff Mass at 8:12 PM