Wikipedia says:"Convergence zone usually refers to a region in the atmosphere where two prevailing flows meet and interact, usually resulting in distinctive weather conditions.
An example of a convergence zone is the Intertropical Convergence Zone (ITCZ), a low pressure area which girdles the Earth at the Equator. Another example is the Sout Pacific convergence sone that extends from the western Pacific Ocean toward French Polynesia.
A smaller example of a convergence zone occures in the Puget Sound region, known as the Puget Sound Convergence Zone. This happens when winds in the upper atmosphere are split by the Olympic Mountains. The winds then converge beyond the mountains, producing convection uplift that results in the development of clouds and even stormy weather.
Convergence zones can also be associated with sea breeze fronts." (my emphasis in blue)
The Olympic Mountains are beautiful. So are the Cascades. The snow topped mountains on the horizon look just as they are seen in the best of photographs. While I'm out today I'll see if I can get a decent photo of either of them. I know there are perfect photos online I can paste in here...but, it gives me another reason to get out today. I need to find a closer Trader Joe's for more Two Buck Chuck anyway.