Shrill cry of ecstasy in brief storm (6)
I believe the answer is:
squeal
This clue could be a double definition.
'shrill' is the first definition.
(thesaurus)
'cry of ecstasy in brief storm' is the second definition.
'squeal' can be an answer for 'cry' (thesaurus). I am unsure of the 'of ecstasy in brief storm' bit.
Can you help me to learn more?
(Other definitions for squeal that I've seen before include "Equals (anag)" , "Inform on someone" , "Split" , "Shrill sound" , "Screech" .)