Supercell Thunderstorms vs. Aircraft

Supercell thunderstorms are intense and violent thunderstorms. They are intense because of the strong vertical wind shear included in the storm. Vertical windshear is the change in wind velocity and direction with altitude. For example, the wind aloft may blow a North at 60 mph while the wind at the surface may blow East at 30 mph. This strong vertical windshear creates what is known as a mesocyclone, which creates that iconic supercell bell shape shown below.

Supercells are extremely dangerous for aircraft because there is an intense updraft at its core, and downdraft around the core. This change in horizontal wind shear can cause an aircraft to have extreme turbulence. Additionally, the mesocyclone within the supercell may create a tornado which can result in very high winds. Finally, the creation of hail is common due to the tall structure of the storm allowing for hail to accumulate as it travels between up and down drafts. The image below shows a supercell cut in half to illustrate the wind direction.

Aircraft caught in this storm should attempt to fly out of it as quickly as possible. Conditions for these storms to form are warm fronts approaching, unstable atmosphere (where cold air aloft wants to sinks and warm air from the surface wants to rise), and finally extreme vertical wind shear is the last ingredient for supercell storms.