A supercell thunderstorm is the most dangerous of any thunderstorm. A supercell can last for several hours and typically contains severe weather. In a supercell thunderstorm, it can produce damaging winds, tornadoes, and even large hail.
To be defined as a supercell it needs to have a rotating updraft. Most supercells move to the right of the wind and they have strong vertical speed and directional wind shear. Supercells are well organized and can move at speeds over 100 mph!
We typically see supercell thunderstorms in the spring and summer months.