Travelling, he got into a violent tornado (2,3,4)
I believe the answer is:
on the road
'travelling' is the definition.
(on the road is a kind of travelling)
'he got into a violent tornado' is the wordplay.
'got into' means one lot of letters goes inside another.
'a violent' indicates an anagram.
'tornado' is an anagram of 'ontroad'.
'he' inserted into 'ontroad' is 'ON THE ROAD'.
(Other definitions for on the road that I've seen before include "Travelling (like Jack Kerouac?)" , "In the Fifties, a novel" , "accompanying The Travelling People?" , "way to travel" , "Jack Kerouac novel" .)