There are a number of documented cases of large chunks of ice falling out of a clear blue sky. After we eliminate ice falling from airplanes or nearby thunderstorms, there still appear to be some events that remain unexplained.
These unexplained falling ice chunks are been given a rather inappropriate name: megacryometeor. Why don’t we just call them “falling ice chunks” or FICs for short, at least until they receive an explanation?
It almost certainly is some sort of unusual atmospheric phenomenon, as ice balls from space would vaporize before they reach the ground.
An unknown blogger (in Spain?) has been documenting news articles about all manner of falling ice chunks since the Dubuque event. The blog is called HALS, which is the plural abbreviation for hydroaerolite—certainly a better name than “megacryometeor”—though this perhaps is also a geological term1 used to describe “silty sediments transported by the wind and deposited on a temporarily wet surface”.
Obviously, more peer-reviewed scientific research needs to be done on these falling ice chunks, megacryometeors, hydroaerolites, or what have you.
1 For example, see Földvári, A. (1958). “Hydroaerolite” Rocks in the Quaternary Deposits of Hungary. Acta Geologica Hungarica 5, 287-292.