original: they are most often cyclonic , that is , associated with a localized low-pressure region within a severe thunderstorm .
simplifications: they are most often cyclonic , that is , associated with a localized low-pressure region within a severe thunderstorm . they are often cyclonic , which is associated with a localized low-pressure region in a thunderstorm . they are most often cyclonic , that is , associated with a localized low-pressure region within a severe thunderstorm . they are most often cyclonic , that is , associated with a restricted low-pressure area within a bad thunderstorm . they are usually cyclonic , meaning they are associated with a localize low pressure area within a severe thunderstorm . they are most often cyclonic , that is , linked with a localized low-pressure region in a bad thunderstorm . they are most often cyclonic , which involves a low-pressure region in a severe thunderstorm . they are most often cyclonic , that is , related with a localized low-pressure area within a severe thunderstorm .