What is the cause of a tornado?
Many tornadoes, including the strongest ones, develop from a special type of thunderstorm known as a supercell. A supercell is a long-lived, rotating thunderstorm 10 to 16 km (6 to 10 mi) in diameter that may last several hours, travel hundreds of miles, and produce several tornadoes. The complete process of tornado formation in supercells is still debated among meteorologists. Sometimes the interaction between the warm air updraft of a storm and winds that vary at different altitudes causes a stable, rotating updraft to form, along with a cooler downdraft on the back side of the storm. Tornadoes form between the updraft and downdraft. However, the details of why a tornado should form there are still not clear.
