Bird, huge one, climbing moment before storm (9)
I believe the answer is:
cormorant
'bird' is the definition.
(cormorant is a kind of bird)
'huge one climbing moment before storm' is the wordplay.
I cannot really see how this works, but
'one' could be 'an' (I've seen this in other clues) and 'an' is present in the answer.
'moment' could be 'mo' (slang abbreviation. e.g. 'just a mo') and 'mo' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for cormorant that I've seen before include "Black diving bird" , "Large, voracious seabird" , "Large diving bird" , "High-flier" , "Glutton" .)