Is there a connection between PTSD and a gloomy climate at the base?

Horrible story the other day about an Iraq war veteran in Washington State who shot and killed a Park Ranger and then died of hypothermia in a creek in Mt. Ranier National Park while trying to elude capture.  Mount Rainier gunman died of drowning, hypothermia-officials

I am not defending the actions of the vet turned murderer who froze to death in the woods.  But there is one thing I wanted to point out. 

The Mt. Ranier area of Washington State is perhaps the cloudiest locale in the USA.   There is a 70% chance of total cloud cover in that area of Washington. Link..  Compare that to Fort Irwin near Barstow Califiornia where there is a 73% chance of sunshine. 
   
Of course sunshine, or lack therof, can affect a person's mood .

Certain circuits in our brain respond to the amount of light during the day, and these circuits have a strong influence over our mood. Therefore, in the winter months, when there is less daylight, is is common for many people to feel a depressed mood.

This article points out that Joint Base Lewis-McChord in Washington State was named the most troubled base in the miltary.  Army Base on the Brink

The base, an hour or so south of Seattle, was named by the government-owned, independent news source Stars and Stripes last year as the most troubled in the military, thanks to an “incredible” number of incidents rooted in post-traumatic stress disorder, says Joseph Carter, a former Army sergeant with two Iraq tours under his belt.

The Stars and Stripes article is worth a read..Joint Base Lewis-McChord rocked by scandal

Plagued by one scandal after another, from violent mental breakdowns to steroid abuse and allegations of killing for sport, Joint Base Lewis-McChord in Washington state this year developed a reputation as the most troubled base in the military... 

.. More than 14,000 servicemembers returned from deployments in Iraq and Afghanistan to the base...

Could there be some connection between the effects of PTSD and the climate? I suppose there is a  chance that sunny weather might help some soldiers in their fight against PTSD, or perhaps its closer to say that being stuck where the sun don't shine makes it even more difficult.