They look like Meso Convective Vortices. At the least they’re Meso Convective Systems.
This MCS/MCV [below] entered the Gulf of Mexico after exiting the Texas coast Thursday April 29. It dissipated on April 3 around Louisiana / Alabama.
This image shows a MCS/MCV entering the Gulf today April 4 off the Texas coast, and one also exiting the Gulf off Florida’s east coast which entered the Gulf south of Louisiana in the AM hours on April 4 2012.
Here’s a cool movie showing them All…