An alliteration is a group of words that start with the same letter or sound, so that phrase is an alliteration because warm, west, and wind all start with "w".
Alliteration is a stylistic literary technique that we can identify when two or more neighboring words have the same initial consonant sound, these words may be separated by short words like the, and, a, of, or, and to. It is often employed to set the pace, the tone, or the mood of a literary work or for emphasis.
The words “warm wind, the west wind” are an example of alliteration because these neighboring words have the same initial consonant sound.
