An EF-3 Fire Tornado

Powerful!:

The fire whirl, or fire tornado, that swept into Redding, California on July 26, appears to have had winds as strong — if not stronger than — an EF-3 tornado, according to the National Weather Service.

Why it matters: The Carr Fire now ranks as one of the state's largest and most destructive wildfires on record. The extreme fire behavior exhibited on July 26 allowed the blaze to jump a natural fire break — the Sacramento River, and enter the city of Redding. So far, the fire has claimed at least 6 lives.

The National Weather Service typically conducts damage surveys after suspected tornadoes, and determines the strength of such an event based on the damage it causes. In this case, the Weather Service and CalFire are conducting a joint investigation.

So far, they've found evidence, including transformers that were twisted and thrown to the ground, of winds in excess of 143 miles per hour, according to a tweet from the Weather Service office in Sacramento.

“It was definitely a massive one, and that just speaks to how intense the heating was,” National Weather Service meteorologist Mike Kochasic told the Los Angeles Times. “It created such a massive whirl that it looked like a tornado … and it takes an impressive amount of heating and local wind swirling up to create something like that. It was quite a monster.”

Maybe the most powerful tornado in California history:

The Los Angeles Times reports that the so-called fire tornado lasted about an hour and a half, measuring up to 500 yards (five football fields) in diameter, with wind speeds estimated as exceeding 143 miles per hour. Fire tornadoes are caused by the extreme amount of heat often generated by long-burning wildfires, the Times notes, but are still exceptionally rare. “Depending on the final number, this might actually be the strongest ‘tornado’ in California history, even if it wasn’t formally a tornado,” one scientist told the Times. “But this fire whirl was almost certainly longer-lived, larger in spatial scope and perhaps even stronger from a wind speed perspective.”