Fuss about fleet, initially adrift in storm (7)
I believe the answer is:
tornado
'storm' is the definition.
(I know that tornado is a type of cyclone)
'fuss about fleet initially adrift' is the wordplay.
'fuss' becomes 'todo' (both can mean a commotion).
'about' is an insertion indicator.
'fleet' becomes 'RN' (abbreviation for Royal Navy).
'initially' indicates taking the first letters.
The first letter of 'adrift' is 'a'.
'rn'+'a'='rna'
'todo' going around 'rna' is 'TORNADO'.
'in' is the link.
(Other definitions for tornado that I've seen before include "Violent twister" , "A major blow" , "Donator of fierce wind" , "RAF fighter; whirlwind" , "It's a big blow" .)