1.   Even brief air disturbance will set off the alarm.

2.   Another cluster of thunderstorms will be found over southern Texas as a upper air disturbance spirals inland from the Gulf of Mexico.

3.   The potent upper air disturbance that brought snow to the mountains of Montana on Tuesday will spin across the northern Rockies on Wednesday.

4.   They said the staff had started their work stoppage last Wednesday, but it had not resulted in any air traffic disturbance.