Ran round in the commotion caused by a storm (7)
I believe the answer is:
tornado
'a storm' is the definition.
(type of weather)
'ran round in the commotion' is the wordplay.
'round' is an anagram indicator.
'in the' is an insertion indicator.
'commotion' becomes 'todo' (synonyms).
'ran' with letters rearranged gives 'rna'.
'rna' inserted inside 'todo' is 'TORNADO'.
'caused by' is the link.
(Other definitions for tornado that I've seen before include "Strong wind" , "A violent and destructive whirlwind" , "Donator of fierce wind" , "This is quite a blow" , "Type of cyclone" .)