Temperatures Inversions.

Dan said there has been some discussion on temperature inversions as of late. Hum I wonder why? He asked if I would post some info on inversions on the blog. I am a sucker for good weather chatter.


If you have been in the Cascade Mountains over the past few days, you have no doubt noticed the extremely cold temperature east of the crest and the warm temperatures to the west. Temperature Inversions are a very common winter weather phenomenon along the entire western mountains range.

Notice the single digits temps to the east and 40-50degrees over Seattle. 


And then the lack of pressure gradients and wind.  Inversion....




During the winter when a ridge of high pressure moves over the land the wind is light and the skies are clear. At night with the clear skies, the temperatures drop rapidly and cool air, which is heavier than warm air, pools on the valley floor. Often this process results in the formation of fog as temperatures drop to the dew point. This situation where the cooler air is near the surface of the ground and temperatures warm as you travel up in elevation is called an inversion. With the cold air stuck in this bowl of a valley and no wind to mix and warm the air, the cold air sits until the sun can heat up the ground enough to break the inversion. Fog makes it even harder to break up this inversion because the fog reflects the sun’s attempts to warm the ground, keeping the valley cool while the higher elevations are seeing sunshine and sitting a good 20+ degrees warmer than the valley. The best way to break this inversion problem is to get some storms to move through the area, which is something, that is currently underway.