Friday, January 17, 2014
The Great Wall of High Pressure
The green is a wall of high pressure that has been in place along the West Coast since about Thanksgiving. It was there last winter, as well.
Along the West Coast, the wet season is the colder half of the year. Because of the high pressure system, storms from the Pacific move up over Alaska down into the Ohio Valley and then out over the Atlantic.
The drought in California has become terribly serious. Per Jan Null, San Francisco is on track for the driest January in its 165-year history with 0.03 inches. That is much drier than the previous record of 0.26 inches in 1920.
Their "water year" is July through June. With only 2.11 inches, that, too, is a record.
A briefing document on the drought from the California state government is here.
ADDITION: Dr. Cliff Mass has a good write up on the California drought here.