I should actually clarify...west winds alone doesn't mean less convergence...it's more of the winds with respect to the front. Typically with cold FROPAS they do so in a more northwest to southeast fashion...so if you have like S, SW, SE winds...they're going into the front ...air is converging which means upward motion. If sfc winds are more W its kind more parallel to the front so there isn't much convergence. At least that's how I've always understood it