A rare fire whirl, also known as a fire tornado, briefly made an appearance near Sao Paolo, Brazil. The swirling fire tornado was reportedly several meters high and brought traffic to a standstill. The Christian Science Monitorexplains how the fire whirl formed.
When there is a warm updraft of air and convergence of fire, say from a wildfire, a vortex of flame can occur. As the heated air from the fire rises, strong air currents cause flame to spin, shaping it into a tornado.
Severe drought and strong winds in Sao Paolo have created conditions which makes fire whirls possible. It has not rained for three months in Sao Paolo. Take a look: