晴嵐 is a loaded pair of characters: as a set phrase it names one of the "Eight Views" (hakkei) borrowed from Chinese landscape painting into Japanese art — "clearing mountain mist," the scene of haze lifting off a slope as rain passes. VIZ's "clear storm" is a defensible plain gloss of the individual kanji but loses that specific art-historical image; the technique is named after a painting motif, not a weather pattern, which puts it closer in spirit to Water Breathing's more poetic forms than to Sanemi's usual blunt meteorology (dust storms, typhoons).
風樹 ("wind tree") completes the picture: a tree bent from years of standing in prevailing wind, its trunk permanently curved. Paired with 晴嵐's clearing-mist imagery, the full name reads almost like a hanging-scroll title rather than a battle cry — a brief lyrical outlier inside a form-set that otherwise names its techniques after literal weather violence. That contrast is worth noting for a Hashira defined by rage and hatred of demons: even his gentlest-sounding technique name still cuts flesh.