Violent whirling wind-storm (7)
I believe the answer is:
tornado
I believe this clue is a double definition.
'violent whirling wind' is the first definition.
(I've seen this before)
'storm' is the second definition.
(type of weather)
(Other definitions for tornado that I've seen before include "Terrible current" , "Windy hazard" , "Rapidly whirling column of air" , "Road not turned in the windstorm" , "lot of wind" .)