predominant vs prevailing

predominant and prevailing both are adjectives.

Word	Noun	Adjective	Verb	Adverb
predominant	No	Yes	No	No
prevailing	No	Yes	No	No

As adjectives, predominant and prevailing are synonyms defined as:

Other synonyms of predominant include dominant, prevalent, rife.

predominant (adjective)	prevailing (adjective)
having superior power and influence	most frequent or common
most frequent or common