Super Rain Shadow

 There are rain shadows.... and then there are super rain shadows.  

On Sunday, a super shadow will produce an area of virtually no rain over northern Puget Sound country. And another super rain shadow will occur over the eastern slopes of the Cascades.

As I have discussed many times in this blog, when air approaches a terrain barrier, it is forced to rise on one side, producing bountiful precipitation, and when it descends the other side, the air is compressed, warms, and dries (see figure).  The wet side is the windward side, the dry side, the leeward one.

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