Lack Of Extreme EF-5 Worst Case Tornadoes In Recent Years Might Just Be A Quirk In How We Measure Them

An EF5 tornado pictured here destroying part of Moore,
Oklahoma on May 20, 2013. That was the last
officials EF5 tornado recorded in the U.S. 

Unless one of the intense EF-4 tornadoes that hit Arkansas earlier this month is upgraded, which is possible but doubtful, there's been a strange 12-year dearth of the most powerful tornadoes possible. 

 There hasn't been an EF-5 since May 20, 2013 when such a super-powerful twister trashed the Oklahoma City and Moore, Oklahoma area, killing at least two dozen people. 

The intensity of a tornado is measured in a six point scale called the Enhanced Fujita Scale, named after the 20th century groundbreaking tornado researcher Tetsuya Fujita.

The scale goes from EF-0 which is the weakest version of a  tornado to EF-5, which are the worst of the worst. 

An EF-5 tornado is strong enough to take a well-built home, shred it, and leave just a bare concrete pad behind.   They can destroy steel-reinforced concrete structures, and  any trees left standing have their barked removed. These tornadoes can suck the asphalt off of roads, and dig trenches in fields. 

They are nothing to mess with. 

EF-5 tornadoes are rare. Of the 1,000 or more tornadoes that hit the United States each year, on average only one of them in a given year would be an EF-5. 

Lately, though, there's been an EF-5 drought.

Since the Moore tornado of 2013, we've had quite a few EF-4s, which are dangerous and deadly enough, but no EF-5s.

Lots of scientists and others have wondered why. 

As Yale Climate Connections tells us, the lack of the super intense EF-5 tornadoes might not be from just dumb luck, or a weather pattern or climate change. 

It might be the way they are measured. 

Says YCC:

"....the absence of top-rated twisters may simply be an unintended consequence of the way house destruction is now accounted for.

Before the Fujita scale was updated in 2007, a well-built house swept clean from its foundation was one of the hallmark indicators of an F5 tornado.

But in the enhanced scale, the average value of winds expected to produce a clean sweep is at the very top of the EF4 range instead of reaching EF5. The result: Since the adoption of the enhanced scale, at least 13 high-end EF4 tornadoes have fallen short of EF5 ratings, despite each of them having swept site-built, well construction houses off their foundations."

Researchers said it might be more plausible to drop the estimated winds of an EF5 from 200 mph to 190 mph.  If that were to happen, perhaps 13 EF4 tornadoes since 2008 would be "upgraded" to EF5s 

A basic question here, notes Yale Climate Connections, is should tornado ratings be more reflect of total impacts and note entirely tied to wind speed estimates?

Experts might revise the criteria for how EF5 tornadoes are measured but there's no final decision on that. And I don't know when a decision might be reached.  

Of course, to tornado victims, if a twister destroys a house and kills or injures its occupants, it doesn't really matter if the thing was an EF4 or EF5.  All that matters is the tragedy itself. 

Another thing to consider about tornadoes. Since climate change seems to affect all weather events, what about tornadoes?

So far it doesn't really seem like climate change has caused an overall trend toward fewer or more frequent tornadoes. It has made tornadoes more variable. Tornado outbreaks seem to have generally gotten bigger, but there are longer quiet periods between outbreaks.

Tornadoes seem to have become more common in the winter than they once were, and tornadoes seem to be hitting the eastern United States more frequently than they once did.

For example: New York had a record number of tornadoes in 2024. It's also only March, and New York has seen two tornado warnings already this year, though tornadoes have not been confirmed to have touched down.  

Like so many things related to climate change, though, its effects on tornadoes is complicated.