The EF Scale Explained: Why You Need an Emergency Tornado Shelter

Tornadoes, hurricanes, and severe storms all seem to have their own rating system. Hurricanes have “Categories”, tornadoes had the “F” scale, and now tornadoes have swapped over to the “EF” scale. With all these measures of severe storms, it can be tough to keep track of it all. In an effort to help people understand the different ratings, today’s blog at Stormbox is all about the EF scale used to measure the magnitude of tornadoes. Keep reading to learn more, and if you are interested in quality storm shelters, contact our team at Stormbox now to get started.

What is the EF Scale?

The “EF” in the “EF Scale” stands for the Enhanced Fujita Scale. According to the National Weather Service, the Enhanced Fujita Scale is a more comprehensive version of the Fujita Scale developed by Dr. Tetsuya Fujita. The original Fujita Scale (F Scale) was developed to categorize tornadoes by estimated wind speeds and damage left behind in a given tornado’s wake. However, the F Scale had limitations, such as few damage indicators, no account for construction quality, no correlation between damage and wind speed, and occasionally flawed or inconsistent ratings. That’s why the F Scale was replaced with the new EF Scale in 2007. The EF Scale was developed by decorated meteorologists, wind engineers, and other industry professionals.

The EF Scale takes into account more variables than its predecessor, with 28 damage indicators, each boasting 8 degrees of damage apiece. This enables industry professionals to more accurately and consistently rate the magnitude of tornadoes on a scale from EF-0 through EF-5 with EF-0 being the least severe and EF-5 being the most severe tornadoes.

The EF Scale Ratings

As mentioned above, there is a multitude of wind speed, damage, and damaging factors that go into the determination of a tornadoes’ EF rating. However, there are some common factors that can be observed that act as strong indicators toward which category a given tornado should be placed in. It’s worth noting that all wind speed ranges require gusts lasting three seconds or longer.

EF-0

EF-0 tornadoes are considered to be weak and can be described as a gale. Wind speeds in an EF-0 tornado are typically between 65 and 85 miles per hour. With a tornado of this magnitude, you can expect minor damage to homes. In many cases, the only damage is a few loose shingles blown away and outdoor furniture tipped on its side or moved across the property.

EF-1

EF-1 tornadoes are considered to also be weak but can also be described as moderate. In a tornado of this strength, you can expect wind speeds between 86 and 110 miles per hour. An EF-1 tornado will often cause moderate damage to homes and properties, breaking windows and doors. Depending on the quality of the build of the home, there may be more or less damage. But in most cases, the home will be more or less okay.

In tornadoes of this magnitude, it is still worthwhile to take shelter in your above-ground tornado shelter or storm cellar.

EF-2

EF-2 tornadoes are considered to be strong tornadoes and they start to present a higher level of danger than the previous tiers. EF-2 tornadoes can be described as significant and you can expect wind speeds between 111 and 135 miles per hour. A tornado of this category will tear roofs off of buildings, snap small trees, and lift lighter vehicles off of the ground. Though EF-2 isn’t near the highest magnitude on the scale, they are still to be taken very seriously as they can be extremely dangerous nonetheless.

EF-3

EF-3 tornadoes are also considered to be strong tornadoes that come with wind speeds between 136 and 165 miles per hour. They can be described as severe and should not be taken lightly. EF-3 tornadoes can cause serious damage to homes and even larger buildings like malls and businesses. Tornadoes of this magnitude possess the strength to turn over trains and lift heavy vehicles off of the ground with ease.

EF-4

EF-4 tornadoes are considered to be violent and very dangerous. EF-4 tornadoes often experience wind speeds between 166 and 200 miles per hour and are described as devastating. This strength of tornado will level even the best-built homes and buildings with minimal effort. Cars of all sizes can be thrown and even lighter objects are thrown at speeds great enough to become deadly missiles.

EF-5

EF-5 tornadoes are at the highest end of the scale and are also very violent and extremely dangerous. They are of the most powerful magnitude and strength, and often experience wind speeds of greater than 200 miles per hour. Tornadoes of this magnitude cause catastrophic damage. Often the foundations of homes will be all that remains. Automobiles and other large objects can be thrown in excess of 300 feet and at incredible speeds.

Stormbox above-ground tornado shelters are built to withstand the strength of even EF-5 tornadoes with a wind-speed rating of up to 250 miles per hour.

Why the EF Scale Is Crucial for Your Safety Plan

Understanding the EF Scale is more than just an academic exercise—it’s a critical component of your emergency preparedness plan. Knowing the potential for catastrophic damage from an EF-4 or EF-5 tornado underscores the importance of having a reliable safe space. An ordinary basement or interior room may not be enough. This is why having a dedicated emergency tornado shelter is essential for true protection. When creating a safety plan, you must account for the worst-case scenario, ensuring your shelter is rated to handle the most violent storms.

Affordable, Above-Ground Tornado Shelters From Stormbox

STORMBOX® above-ground tornado shelters are built to withstand the strength of even EF-5 tornadoes, with a wind-speed rating of up to 250 miles per hour. Our unique shipping container storm shelter design is engineered to meet and exceed FEMA P-361 guidelines, ensuring your family, employees, or community members have near-absolute protection when it matters most.

We hope that you have found today’s blog helpful and educational. While reading about tornadoes can be great fun, being prepared for them should not be taken lightly. Make sure you are prepared, whether you are at home, work, or school, by getting a Stormbox above-ground tornado shelter. Contact our team today to get a free quote for your Stormbox emergency tornado shelter!