Something brewing perhaps before new storm (7)
I believe the answer is:
typhoon
'storm' is the definition.
(I know that typhoon is a type of cyclone)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for typhoon that I've seen before include "Eastern tropical storm" , "Violent storm - WWII aircraft" , "Pacific hurricane" , "Pacific tropical storm" , "Indian Ocean tropical storm" .)