Less Sad in Seattle

Have you noticed that people are a bit happier in Seattle this fall?   More smiles and less complaining?   

One explanation might be the unusual amount of sun this fall, which lifts the spirits and relieves the sufferers of Seasonal Affective Disorder (SAD).

November and December should be dark, gloomy times here in the Pacific Northwest.   The sun is naturally weaker and shorter-appearing due to the time of the year.   And its feeble rays are usually further weakened by considerable cloud cover, as Pacific weather systems reach our region.

In two days we will have the earliest sunset of the year (4:17 PM) and we are within the lowest daylight time of the year (see the sun plot below).

Just thinking about this is usually depressing.   But not this year!  Because this year we have had unusual amounts of sun.

Consider the solar radiation received here in Seattle (below).  We had a rough patch of low sunshine from Nov. 21 to Dec 2, but other than that we have had some relatively bright, sunny periods, including today and the last few days.

Much less sun last year.

Or in 2015 (which had a relatively bright period in early November)

To get so much sun in early December is a gift from the weather gods, that provides a huge psychological boost to those of us trying to get through the winter.   A month from now, the days will be getting noticeably longer and storms will fade a bit.  NOW is when we need the sun and we are getting it.

You may ask:  why the solar bounty this year? 

The reason is that for the past month there has been a persistent upper-level ridge of high pressure just to our north and east, providing descending, cloud-busting air.    This is illustrated below, with a map that shows the anomaly from climatology (difference from average) of the heights of the 500 hPa pressure surface over the past 30 days.   Red indicates much higher than normal heights (or equivalently pressure).  Lots of red just to our northwest...exactly where we need it.

Like sea-level pressure better?  Here is the difference from normal for almost the exact same period.  Higher than normal pressure (yellows and orange colors) offshore

Ironically, a lot of our storms have been heading south into California, which has been hammered by rain, wind, and clouds.

So turn off your light boxes and get outside today....it will make a huge difference in your mood for weeks to come.

from Cliff Mass Weather and Climate Blog https://ift.tt/2PkyTxm