An elevated thunderstorm is a thunderstorm in which the base of the storm is well above the ground surface. One way this can occur is when lifting and instability release takes place but the initial relative humidity of the air during initial lifting is dry. Thus, significant lifting is needed to raise the air high enough to reach saturation. This can produce convective clouds and thunderstorms that have bases well above the surface even though the lifting started from the surface. Another way an elevated thunderstorm can occur is when the lifting begins at an elevation that is well above the surface. The lower level of the troposphere can be stable while there is lifting and instability release in the upper troposphere. This can produce convective cloud bases that are high above the surface. Elevated thunderstorms can produce strong downdrafts since the downdraft can have a significant distance to accelerate toward the surface. Dry air in the troposphere will enhance the downdraft strength due to the negative buoyancy produced from evaporative cooling as rain from the downdraft region of the storm falls into dry air.  |