<ul data-eligibleForWebStory="false">A derecho is a widespread, long-lived windstorm associated with fast-moving thunderstorms.Derechos are not inland hurricanes or tornadoes but produce straight-line winds.They are most common in warmer months and kill more people than tornadoes.Derechos occur May through August, with serial derechos in cooler months.Preparation includes checking weather alerts and taking cover during severe thunderstorm warnings.