CNN CNN International May 9, 2015 09:24:00
Is standing with with more. derek. >> george, central u.s. taking center stage. large hail, damaging winds and long tracks, very dangerous and lethal tornadoes. more on that. take a look at footage comes out of oklahoma sometime yesterday. we had impressive thunderstorms flare up. this is called a shelf cloud. it's seen along the leading edge of an approaching line of thunderstorms. basically, we have a downdraft from the heavy rainfall underneath the thunderstorms. and the air that's pushed out in all directions along the surface of the earth eventually meets up with warmer air allowing it to...
Source: archive.org