Last December, footage was released of a blast that was said to be somewhere in Syria, but there were no details of exactly where or when, nor of what blew up.
It is eerily similar to the Beirut mushroom cloud. But the provenance of the video is suspect, and it is suspicious that the footage begins exactly at the moment of the explosion. At the time there were rumors that this was a Russian ODAB-500 thermobaric bomb.
The closest I can find to a documented fast moving, quickly dissipating mushroom cloud is this video of a Russian ammunition depot explosion last August:
An accident at a Russian Army ammunition depot turned catastrophic today as a series of explosions killed one soldier and hurled shrapnel more than nine miles. At least eight others are reported wounded with windows in a nearby town blown out by the shockwave. The incident, still ongoing, is located outside the Siberian city of Achinsk.How about fertilizer explosions? While I cannot find such a cloud in video of most of them, the closest I could find is this angle of a West, Texas fertilizer depot explosion from 2013 at 0:10 here:
The explosion generated a mushroom cloud over the blast site and sent shrapnel flying as far as 9.3 miles away.
You can briefly see a spherical blast pattern.
It is possible that the pattern is so much more apparent in Beirut because of the proximity to the sea, which could increase the amount of water vapor in the explosion, as opposed to drier Texas.
Still, the allegedly Syrian footage is the closest to Beirut, as it hugs the ground unlike the Russian and Texas explosions.