A wind shear occurs when the wind speed or direction suddenly changes, so that the wind actually is blowing in two opposite directions. The wind shear near the ground set up the spin that developed the fire tornado plume, Lareau said. According to a new study published in the Geophysical Research Letters, a 'firenado' forms a lot like a regular tornado does. Record high temperatures, low humidity, and a 'near-surface cyclonic wind shear zone,' also contributed to the phenomenon. According to the researchers, the wind shear near the ground set up the spin that developed the fire tornado plume.

Source: Daily Mail December 06, 2018 16:13 UTC