It has been nearly eleven years since an EF-5 tornado has been documented in the U.S., but why?

While broken records are rarely a good thing in the weather-sphere, this record is a cause for celebration. If no EF-5s are recorded before May 20, 2024, it will mark 11 years since the US experienced the most destructive kind of tornado.

The last EF-5 was the 2013 Newcastle/Moore, Oklahoma tornado that carved a terrible path of destruction across a heavily populated area, killing 24 people.

Since then, there haven't been any EF-5 tornadoes, which are the rarest but by far the most destructive, on the Enhanced Fujita scale. The previous longest gap between EF-5 tornadoes was from May 3rd 1999 until May 4th 2007.

The original Fujita Scale for tornadoes debuted in 1971, and was applied retroactively to all tornadoes since 1950. Starting in 2007, tornadoes have been rated via damage using the Enhanced Fujita Scale, which offers a more thorough scale.

So why hasn't one occurred in nearly a decade? EF-5 tornadoes are rare and catastrophic, and account for less than one in every 1,000 tornadoes.

Since 1950, there have been 58 F-5 or EF-5 tornadoes, averaging out to less than one per year. Two-thirds of all EF-5 tornadoes occur during the months of April and May.

There are a few theories as to why there has been such a long period without one lately. It is possible that a violent tornado of such strength occurred over an empty field or rural area, but didn't leave enough structural damage for an EF-5 rating.

Some scientists suggest that the tornado drought is due to short-term weather patterns or climate change. As of right now, the jury is out. With any luck, it will be a long time before another tornado of this magnitude impacts the US, or anywhere.