Use the adjective blustery to describe weather that brings extremely strong gusts of wind. It's much easier to fly a kite on a blustery day than when there's no wind at all.
While this word is frequently used for weather — think blustery October days with leaves blowing and people clutching their hats — it can also describe people who act aggressively or confidently but don't follow through. All that blustery talk about your football team's superiority won't mean a thing when they lose badly yet again. The source of blustery is the noun bluster, "loud or indignant talk with little effect," from a Germanic root meaning "blow violently."