Advice to Californians: Vacation in Washington State for Sun and Dry Conditions

California is advertised as the "Golden State" with dry conditions and sun.  Washington is given the bad rap as a place of clouds and rain.

But not this March.  California should properly be called the "Sodden State", while much of Washington has been extraordinarily dry.

For example, it appears that Seattle-Tacoma Airport will end up with 1.37 inches (assuming the forecasts are right), resulting in the second driest March since the airport observations started in 1948.    And Seattle has had seven days with measurable precipitation

Typical March 2019 Weather in Seattle

Typical San Francisco Weather in March

In contrast, San Francisco had 15 DAYS of measurable precipitation for a total of 4.43 inches.

Los Angeles has had 2.10 inches of rain this month.

And Puget Sound has had less clouds and more sun than San Francisco.

To appreciate the recent dry conditions, here is the percent of normal precipitation for the past 30 days.   Large sections of western Washington received 5-25% of normal, while San Francisco northward had 200-400% of the typical amounts. Nevada, Utah and Colorado  were all very wet.

Central/northern California was wetter in March than western Washington.   And our dry conditions were also associated with some very warm periods with strong easterly winds.  The result:  a few days with several wildfires and a pollen storm that brought misery.

The origin of the situation?   A very persistent area of low pressure west of California, as illustrated by the upper level anomaly map (difference from normal heights or pressure) for the past month (see below).   The purple/blue colors indicate lower heights or pressures offshore.  Such low pressure sweeps weather systems into California.  Western WA gets the dregs on the north side of the low.  And high pressure (red colors) to the north of us, coupled with the low pressure to the south, sets up unusual easterly (offshore) flow aloft.  Such flow is dry and dries further as it descends our mountains.

A very unusual, but perfect, configuration to give us a dry, often sunny, but fire-prone month.

And there may be a contributor to this configuration:  a resurgent El Nino, which is associated with warmer than normal sea surface temperatures over the central and eastern tropical Pacific.  Such warmer water forces tropical thunderstorms that push energy into the tropical atmosphere above, in turn forcing a series of waves that propagate into the midlatitudes, resulting in the lower pressure areas west of California.  Think of a rock thrown into a very big lake, with waves moving away from where the rock hits the water.

Finally, if you are worried about Californians rushing northward into western Washington, you should be.  I was going to joke about putting up a wall, but thought better of it.

from Cliff Mass Weather and Climate Blog https://cliffmass.blogspot.com/2019/03/advice-to-californians-vacation-in.html