These two features are mesoscale convective systems. If you ever see "MCS" in a forecast discussion or hear someone on TV mention it, that's the acronym for this system. A MCS is simply an organized cluster of thunderstorms. Usually, each MCS has its own circulation as clearly shown in your picture. They can form anywhere from the mid-latitudes to the tropics, and some tropical waves that potentially become hurricanes may start out as a MCS. In the United States, they develop most often during late spring through summer in the northern Great Plains and migrate eastward.
The two MCSs shown here aren't bowing out and producing large swaths of 70-110 mph winds, which is what you need for derechos. These MCSs are actually propagating southeastward if you watch them on satellite, and it looked like the second system was stronger and had more unstable air to its south. Wind is most likely the biggest threat in regards to severe weather. Hope that helps!
