Real Dictionary

firestorm
countable noun: A firestorm is a fire that is burning uncontrollably, usually in a place that has been bombed.
countable noun: If you say that there is a firestorm of protest or criticism, you are emphasizing that there is a great deal of very fierce protest or criticism.

firestorm in American English
an intense fire over a large area, as one initiated by an atomic explosion, that is sustained and spread by the inrushing winds created by the strong draft of rising hot air
noun: an atmospheric phenomenon, caused by a large fire, in which the rising column of air above the fire draws in strong winds often accompanied by rain

firestorm in British English
noun: an uncontrollable blaze sustained by violent winds that are drawn into the column of rising hot air over the burning area: often the result of heavy bombing