Volcanoes 101 . Site map . Facts T ornadoes don't pack near the energy of a hurricane. It's the way the energy is concentrated that makes twisters so deadly. How tornadoes form Scientists don't completely understand how tornadoes work.
Some tornadoes occur inside tropical cyclones and hurricanes.
But most form where cold, dry air meets warm, most air. The moist air is lifted rapidly, creating tremendous instability and large thunderheads. Violent updrafts and strong winds sometimes combine to form a whirling vortex of air. If the vortex reaches the ground, it is called a tornado. It turns brown or gray because of the dirt and other material it sucks up.