Each year when tornado season rolls around you hear the people on the Weather Channel talking about Tornado Alley.
But have you ever wondered what is Tornado Alley?
And which states are located in Tornado Alley?
We had the same questions and did some research to get all the details for you.
What Is Tornado Alley?
Tornado Alley is a nickname given to an area of the United States that has a reputation consistently experiencing a high frequency of tornadoes in the area each year.
The term was first used in 1952 as the title of a research project to study severe weather in areas of Texas, Louisiana, Arkansas, Oklahoma, Kansas, South Dakota, Iowa and Nebraska.
According to the National Centers for Environmental Information (NCEI), formerly known as National Climatic Data Center (NCDC), Tornado Alley is located in the south-central United States.
Tornadoes in this Tornado Alley region typically happen in late spring, and occasionally in the early fall.
The States In Tornado Alley
Although the boundaries of Tornado Alley are debatable (depending on which criteria you use—frequency, intensity, or events per unit area), the region from central Texas, northward to northern Iowa, and from central Kansas and Nebraska east to western Ohio is often collectively known as Tornado Alley.
The states in Tornado Alley are:
- South Dakota
Meteorologically, the region known as Tornado Alley is ideally situated for the formation of supercell thunderstorms, often the producers of violent (EF-2 or greater) tornadoes.
What Is Dixie Alley?
Have you ever heard of Dixie Alley? It’s another part of the United States that is a hot spot for tornado activity, just like Tornado Alley.
Florida and the Gulf Coast are known as Dixie Alley.
Dixie Alley has a relatively high frequency of tornadoes occurring in the late fall (October through December).
As a result of the frequent thunderstorms, Florida has a high rate of tornadoes in the state.
In addition, when tropical storms or hurricanes move ashore, the embedded convective storms in the rain bands often produce tornadoes.
However, despite the violent nature of a tropical storm or hurricane, the tornadoes they spawn (some as water spouts) tend to be weaker than those produced by non-tropical thunderstorms.
States that make up Dixie alley: it stretches from eastern Texas and Arkansas across Louisiana, Mississippi, Tennessee, Alabama, Georgia, and far western Kentucky to upstate South Carolina and western North Carolina; the area reaches as far north as southeast Missouri.
And, of course, Florida is also included.
About Tornados In The U.S.
Overall, most tornadoes (around 77%) in the United States are considered weak (EF-0 or EF-1) and about 95% of all United States tornadoes are below EF-3 intensity.
The remaining small percentage of tornadoes are categorized as violent (EF-3 and above).
Of these violent twisters, only a few (0.1% of all tornadoes) achieve EF-5 status, with estimated winds over 200 mph and nearly complete destruction.
However, given that on average over 1,000 tornadoes hit the United States each year, that means that 20 can be expected to be violent and possibly one might be incredible (EF-5).
Rating Tornado Intensity With The Enhanced Fujita Scale (EF Scale)
The Enhanced Fujita Scale (EF Scale) is what we use to determine how strong, and how damaging, a tornado is when it touches down.
The EF Scale, which became operational on February 1, 2007, is used to assign a tornado a ‘rating’ based on estimated wind speeds and related damage.
When tornado-related damage is surveyed, it is compared to a list of Damage Indicators (DIs) and Degrees of Damage (DoD) which help estimate better the range of wind speeds the tornado likely produced.
From that, a rating (from EF0 to EF5) is assigned.
|3 Second Gust (mph)
As you can see, there is a good reason that we call a section of the United States ‘Tornado Alley’ due to the high incidences of tornados.
But you may not have known about Dixie Alley and the states that make it up.