Make an attack in unfavourable weather (5)
I believe the answer is:
storm
This might be a double definition.
'make' is the first definition.
(thesaurus)
'an attack in unfavourable weather' is the second definition.
'storm' can be an answer for 'weather' (I have seen 'Violent weather' mean 'storm' so perhaps 'weather' could also mean 'storm'). I am not certain of the 'an attack in unfavourable' bit.
Can you help me to learn more?
(Other definitions for storm that I've seen before include "Uproar" , "Destructive wind" , "Big fuss" , "= Gale force 10" , "Awful blow" .)