Blowy is correct, but "windy" or breezy is better imho. The reason being that it is clumsy, awkward and even sometimes simply wrong to use an adjective which derives from other words (nouns or verbs) which themselves end in a soft or soft-vowel sound. Gale is a good word, galey is wrong.
Reminds me of an machinery auction I went to there was a pump with pipework, one end said blow, the other said suck. The auctioneer announced that lot 85 was a suck and blow job, I bought it.