Stormed at a poor newspaper editor! (5)
I believe the answer is:
raged
'stormed' is the definition.
('rage' can be a synonym of 'storm')
'at a poor newspaper editor' is the wordplay.
'at' says to put letters next to each other.
'a poor newspaper' becomes 'rag' (informal term for a newspaper. I am not sure about the 'poor' bit.).
'editor' becomes 'ed'.
'rag' next to 'ed' is 'RAGED'.
Can you help me to learn more?
(Other definitions for raged that I've seen before include "Spoke violently" , "Flipped one's lid" , "expressed vitriol?" , "Spoke loudly and angrily" , "was having fits" .)