Warm air rises, resulting in a decrease air pressure.
Explanation:
Tornado is the rapid and violent rotation of column of air which move from the thunderstorm to the ground.
It is formed when there is collision between warm and cold air. The cold air which is more sense than the warm air is pushed over the warm air which result in thunderstorms. The warm air then rises which result in decrease air pressure causing an updraft. The updraft then begin to rotate as there are variations in wind speeds and directions.
The interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays.