California is a drought state. Our so called “Mediterranean” climate falls in a global zone just poleward of the great deserts and along the western continental margins that is characterized by winter rain and summer drought.
Should we be surprised when sometimes rainfall extends into summer months and summer drought extends into winter?
The 2013-2014 rainfall season has just set a new record in San Francisco, the location with the longest continuous record. This record extends back 164 years to 1850. We believe the current California climate has been in place for about ten thousand years since the most recent ice advance receded, and probably for about two million years intermittently during the “interglacial” episodes like we live in today. Statistically, a 164 year sample has a low probability of representing what is “normal”.
This is a six month sea surface animation beginning in August, 2013. We can see that there is an unusual amount of extremely cold water upwelling off Baja California beginning in August and extending north during the “winter” months. The fish love this because it brings up lots of nutrients including Carbon from the deep ocean, but this pattern removes the areas of warm surface water that fatten the clouds with rain.
You can see this “hot spot” of ocean temperature in the previous animation but it shows better in this projection. For perverse reasons only NOAA would know, this animation will not run. In various configurations this has been around since August.
This animation is from 12000 meters at the very top of the atmosphere and the bottom of the stratosphere. Essentially, we are looking at areas of warm air rising and “denting” the bottom of the stratosphere and “sinkholes” where the stratosphere is warping down. One such downwarp can be seen causing the misnamed “polar vortex” that caused the recent cold wave back east.
We have noticed that a red dot seems associated with dry spells in California, and we are especially interested in the possibility that this dot is associated and offset east (leeward) from the hotspot in the ocean below.