We received a handful of photos in the First Warning Weather center this morning of what appeared to be a front moving through Austin.
Contrary to what is usually responsible for causing such a sharp demarcation in the clouds, this was actually not caused by a cold front.
There is a weak, diffuse cold front blowing through at the low levels of the atmosphere this morning — but the interesting cloud features seen here are 10,000 – 20,000 feet high. So what’s the deal?
The boundary of light / dark clouds appears to be caused by a mid/high level moisture gradient from the active subtropical jet stream. The jet stream is moving moisture from the Pacific Ocean into Central and South Texas today, and the darker clouds show an area of thicker, more concentrated moisture.