EF0 Tornado - Enhanced Fujita Scale

Tornadoes are one of nature's most fascinating and yet terrifying phenomena. They can range from mild twisters to violent, mile-wide vortices of fast-moving air leaving complete destruction in their wake. The Fujita Scale was developed by Ted Fujita in 1971 to classify a tornado's intensity based off the destruction left behind. This scale was later modified in 2007 to create the Enhanced Fujita Scale which rates tornados into six distinct categories, EF0 through EF5.

The most common and least powerful of all tornadoes are those within the EF0 category. An EF0 tornado is closer in strength to what one might expect out of a straight-line wind during a thunderstorm, or a strong gust on a windy day. With speeds ranging from 65-85 mph, damage is typically minimal, and injuries or deaths are rare with EF0s. However, despite their relatively weak nature, these twisters still have the potential to inflict harm and damage on communities.

EF0s are the most common type of tornado across every continent except Antarctica, where there’s never been a tornado reported. As mentioned, these tornadoes are generally not very destructive. Wind speeds range between 65 and 85 mph (105 - 137 km/h). Speeds within this range have the potential to uproot small trees, tear shingles off rooftops, blow out car windows, and toss around outdoor furniture. Well-built and sturdy structures are typically left unscathed although barns and sheds can blow over. All-around damage is typically not very extensive but injury and death to humans is still possible.

A good example of a this was an EF0 that struck Thompson, Georgia on May 24th, 1955. At around 8 pm local time, the weak but deadly twister hit just southwest of the town, killing 3 people. To date, this remains the deadliest EF0 tornado on record.

Between 1950 and 2022, only 25 people have been killed by F0 or EF0 tornadoes in the United States. Despite this, tornadoes of this intensity are by far the most common. It’s estimated that about 53% of all tornadoes are classified as EF0 worldwide according to the National Weather Service. In the United States, this figure is slightly lower with about 46% of all reported tornadoes between 1950-2022 falling into the EF0 category.

As far as size is concerned, tornadoes of this magnitude are generally small. It's not uncommon for the base diameter of these twisters to be 10- or 20-yards across. The average EF0 is about 100-200 yards across. Although rare, weak tornadoes, like EF0s, can become much larger and extend to over half a mile in diameter.

It's common for tornadoes of this scale to not stay on the ground for very long. They often lift after just a few minutes, or sometimes seconds, after first touching down. Similar to their short lifetime, tornados in this category generally don't travel very far. These twisters typically have path lengths between just a few hundred yards to a few miles. On average, they stay on the ground for just 1.1 mile. Again, this is a generalization and there are many circumstances where weak tornadoes have far exceeded this figure.

Unlike EF4’s and EF5’s, tornadoes on the weaker end of the spectrum have been known to occur in a variety of storms other than just supercells. A supercell is a type of rotating thunderstorm that often spawns the strongest tornadoes. However, EF0’s are common in other storm families such as squaw lines, tropical storms, and hurricanes.

Additionally, weak tornadoes, such as EF0’s, have been known to develop at almost any time of year and anywhere in the world. They’re most common in the U.S., as is every tornado category, but are also frequent in Europe, Australia, Bangladesh, Japan, Argentina, and South Africa. Here’s a map showing the tornado hotspots around the world in orange.

For a tornado to form, there needs to be a combination of warm moist air, cold dry air, and wind shear. Although not a requirement, tornadoes tend to favor areas with flat land instead of mountains. The places shown in the map are generally flat, and often have the necessary atmospheric ingredients conducive for tornado development.

A recent, and memorable, example of an EF0 tornado is the one that hit Compton, CA on May 4th, 2023. Compton sits within LA County in Southern California which is a relatively mountainous region. Tornadoes aren’t usual in this area. As mentioned, tornadoes, especially large ones, don’t prefer mountains and instead tend to form over flat land. EF0’s are kind of an exception in this regard and have been known to be capable of forming just about anywhere.

The Compton twister touched down around 8:55 am local time, catching many residents off guard. Yard furniture was tossed around, and minor damage was sustained to commercial and residential properties. This included shingles flying off roofs, car windows shattering, and a large hole developing on a warehouse roof. Thankfully, no injuries or deaths were reported.

Tornadoes of this magnitude often strike areas where residents are unprepared for such scenarios. That’s why it's important to be knowledgeable about what to do in a tornado situation, even if you live in an area that isn’t prone to twisters. The good news is that it's very easy to stay safe in a weak tornado. The best thing to do is to, obviously, go inside. Once inside, you want to go to the center of your home, preferably to an interior closet or bathroom where there’s a maximum number of walls between you and outside. It’s also a good idea to protect your head and body by wearing a helmet and body pads if available.

In an EF0, it’s hard to get hurt if you’re within the walls of a well-built home. Unless you’re near a window that gets broken by wind or debris, you should be safe inside a sturdily built structure. However, an EF0 can rapidly intensify to a stronger tornado, capable of inflicting much more damage. EF5’s, which destroy almost everything, are known to start off as weak EF0’s or EF1’s. This is why it's important to always prepare for the worst, and stay tuned for weather updates via radio, social media, or TV.