Fire tornadoes could threaten California

The US National Weather Service (NWS) warned on January 14 that the combination of strong winds and severe dry conditions creates an extremely dangerous situation in which any new fires could explode. about scale. The forecast did not mention tornadoes, but meteorologist Todd Hall said fire tornadoes could occur in extreme conditions. From the California wildfires, researchers in Massachusetts are looking to recreate a smaller-scale version of the phenomenon in the lab.

Fire tornado or fire tornado are words that scientists, firefighters and people use to describe the same type of phenomenon and there is no consensus. Some argue that fire tornadoes are formed solely by heat, while fire tornadoes consist of clouds created by the fire itself. The National Wildfire Coordination Organization’s glossary does not mention fire tornadoes but defines a fire tornado as a swirling column of hot air and gas that rises from a fire and contains smoke, debris and flames. Some large fire tornadoes have the same intensity as small tornadoes.

Wildfires with turbulent columns can create lightning-producing clouds or vortexes of ash, smoke and flames, according to Leila Carvalho, a professor of meteorology and climatology at the University of California, Santa Barbara. The rotation results from wind shear and a very hot local low pressure system.

Fire tornadoes can make fires stronger by sucking in air. “It created a track and where it went, the destruction was the same as any other tornado,” Carvalho said. In 2018, a fire tornado the size of three football fields killed a firefighter when it erupted in a giant wildfire near Redding, about 400 kilometers north of San Francisco in southern California. Scientists later described the cloud reaching 11 km in the air and generating winds of up to 230 km/h.

Research results also show that fire tornadoes can carry fire embers far away, according to James Urban, assistant professor in the Department of Fire Engineering at Worcester Polytechnic Institute. They can also change fire behavior such as changing direction. The interaction between wind, fire column and terrain determines whether a fire tornado will form or not. For example, some terrain will restrict the flow of air, creating conditions for the development of circular motion.