The Second Violent Tornado of 2017 Happened Over the Weekend in Texas

At a Glance

• An NWS damage survey has concluded that a north Texas tornado on April 29 was an EF4.
• This is the second tornado rated EF4 so far this year.
• In recent years, EF4s have been quite infrequent.

  

A tornado Saturday in north Texas has been rated EF4, a violent intensity not often attained by tornadoes in recent years.

(MORE: Tornado Central)

A survey team from the National Weather Service office in Fort Worth found damage from one of seven tornadoes east of Dallas on April 29 supported an EF4 rating on the Enhanced Fujita scale.

(INTERACTIVE: Experience the Formation of a Tornado)

On the ground for 40 minutes over a 22-mile path, this tornado collapsed every wall of a well-constructed two-story brick house in Van Zandt County, according to a statement released Tuesday by NWS-Fort Worth. 

Severe debarking of numerous trees on that home's property was another indicator that prompted the EF4 rating for this tornado, which later grew to roughly a mile wide. Peak winds at this location were estimated 175 to 185 mph.

Two were killed by this tornado.

(NEWS: Deadly Severe Weather, Flooding)

How Rare Are Tornadoes This Strong?

The Van Zandt County, Texas, tornado was the second EF4 tornado so far in 2017.

The other one occurred in Perryville, Missouri, on Feb. 28, one of roughly five dozen tornadoes from Feb. 28 through March 1.

There were only two EF4 tornadoes in all of 2016, according to the Storm Events database from NOAA's National Centers for Environmental Information:

• Garvin County, Oklahoma (May 9)
• Dickinson County, Kansas (May 25)

From 2000-2010, only 0.5 percent of all tornadoes in the U.S. attained an F/EF4 or higher rating, according to severe weather expert Dr. Greg Forbes of The Weather Channel.

(MORE: Your Monthly Tornado Risk)

An investigation by ustornadoes.com found that an average of seven F/EF4+ tornadoes in the U.S. each year from 1990 through 2010.

Despite the rarity, these violent tornadoes are often deadly.

While only small parts of a violent tornado typically experience EF4 or EF5 damage, Forbes found that 58 percent of EF4+ tornadoes in the U.S. from 2000-2013 claimed at least one life along its path.

(MORE: Why Rating Tornadoes in Rural Areas is Challenging)

The worst tornado outbreaks can spawn swarms of EF4+ tornadoes.

Fifteen violent tornadoes occurred on the peak day of the April 2011 Super Outbreak. These EF4+ tornadoes accounted for almost 90 percent of the tornado-related deaths on April 27, according to the Centers for Disease Control and the Red Cross.

(MORE: Most Tornado-Prone Counties)

The April 3, 1974 Super Outbreak spawned 30 violent tornadoes in just 24 hours. 

Jonathan Erdman is a senior meteorologist at weather.com and has been an incurable weather geek since a tornado narrowly missed his childhood home in Wisconsin at age 7. Follow him on Facebook and Twitter.

MORE ON WEATHER.COM: Tornadoes in History