Quite an Occlusion FTLComm - Tisdale November 30, 1999 This morning the last day of the month of November should see normal temperatures of -15 to -20 yet today it is zero and Environment Canada is talking about +15 in the Swift Current area. This unusal weather is caused by a very large dry airmass located to the South and West of us pushing dry desert air up here and inflating the temperatures. The warm air has strong Southern winds and it

actual slides right up over the cooler local air as it heads North. This creates an interesting sky pattern that can be seen in the composite image below. I have drawn onto the picture a green line that shows the demarkation between the cool surface air and the warmer air streaming over it in what is called an "occlusion" we illustrated one of these in January.

Below is a 180 degree panorama of this morning's 9:00 o'clock sky with its ripples, waves and its occlusion.