One of my main research areas at UAH over the past few years has been atmospheric waves. They are commonly called gravity waves, but they are not anything from space, etc. They are simply waves in the atmosphere similar to those in water. They may be produced by lots of things, including upper level jets, mountains, and sometimes storms running into the pool of cool air near the ground in the early morning. That's what happened this morning over Mississippi, as cool outflow from the storms that moved across our area this morning disturbed the stable low-level air out ahead of it and produced a wave known as a "bore".
The visible satellite image above shows it at 1345 GMT (8:45 am CDT). There is a sharp cloud at the leading edge of the bore, and then several smaller bands of clouds, at the crest of each wave, behind it. Neat stuff.
Dr. Tim Coleman