Looks like those of us in the valley will be enjoying a cloud-topped mixed layer for Christmas Eve. Stratus persists over the valley this morning and the views from the top of Snowbird this morning shows that its a gorgeous day in the mountains with undercast over the Salt Lake and Heber Valleys.
In a cloud-topped mixed layer, radiative cooling at cloud top drives turbulence and mixing in and below the cloud layer. This is a different type of cold pool than we've had thusfar this year and should make an interesting case for the PCAPS program. It is also the closest we're going to be to a "white Christmas" here on the valley floor.