Where Violent Tornadoes Occur Most Frequently

[PerryW]

Just did a little research today into where EF4 and EF5 tornadoes have occurred the most frequently since 1950 and the results are quite interesting. I took eight large "tornado prone" cities and where violent tornadoes have struck in relation to them (within a 50 nautical mile radius) during the past 65+ years. The results are quite interesting...

As you would expect, a lot of violent tornadoes impact central Oklahoma. We all remember the F5 Bridge Creek-Moore Oklahoma monster that killed 36 in 1999 and equally violent EF-5 that killed 24 in Moore just four years ago. In fact, 22 violent tornadoes have struck within a 50 n mi radius of Oklahoma City since 1950.

Oklahoma City 1950-2015 (22 F4/ F5 within 50 n mi)

Wichita, Kansas has also been in the sights of many violent tornadoes since 1950, although not as often as Oklahoma (15).

What I found surprising is two other large cities in the same general area have had far fewer close encounters with violent tornadoes since 1950, even though the perception is they are just as likely as Oklahoma City to be struck.

Dallas-Fort Worth, Texas 1950-2015 (only 5)

Wichita Falls, Texas 1950-2015 (9)

We all know a lot of vicious tornadoes target the "Dixie Alley". In fact, based on the 1950-2015 data, the most dangerous city in the US when it comes to EF4 and EF5 is Huntsville, Alabama with a whopping 25 violent tornadoes occurring within 50 n mi of that city during the last 67 years. Birmingham, Alabama and Jackson, Mississippi aren't far behind.

Huntsville, Alabama 1950-2015 (25)

Birmingham, Alabama (18)

Jackson, Mississippi (17)

I researched one other large city today.......my hometown of Atlanta, Georgia. I knew far fewer violent tornadoes had struck the metro Atlanta area than neighboring states to our west, but the difference is dramatic.......considering Birmingham and Huntsville are less than 150 miles away. Only four (4) violent tornadoes have occurred within 50 n mi of Atlanta since 1950.

I hope you've enjoyed this post.

 

[GTWXAlum]

Great stuff Perry!

Obviously I'm saying this in jest because if the conditions are right, it could happen at any time..but the Atlanta severe weather shield lives!!

 

[Gawxnative]

Just did a little research today into where EF4 and EF5 tornadoes have occurred the most frequently since 1950 and the results are quite interesting. I took eight large "tornado prone" cities and where violent tornadoes have struck in relation to them (within a 50 nautical mile radius) during the past 65+ years. The results are quite interesting...

As you would expect, a lot of violent tornadoes impact central Oklahoma. We all remember the F5 Bridge Creek-Moore Oklahoma monster that killed 36 in 1999 and equally violent EF-5 that killed 24 in Moore just four years ago. In fact, 22 violent tornadoes have struck within a 50 n mi radius of Oklahoma City since 1950.

Oklahoma City 1950-2015 (22 F4/ F5 within 50 n mi)

Wichita, Kansas has also been in the sights of many violent tornadoes since 1950, although not as often as Oklahoma (15).

What I found surprising is two other large cities in the same general area have had far fewer close encounters with violent tornadoes since 1950, even though the perception is they are just as likely as Oklahoma City to be struck.

Dallas-Fort Worth, Texas 1950-2015 (only 5)

Wichita Falls, Texas 1950-2015 (9)

We all know a lot of vicious tornadoes target the "Dixie Alley". In fact, based on the 1950-2015 data, the most dangerous city in the US when it comes to EF4 and EF5 is Huntsville, Alabama with a whopping 25 violent tornadoes occurring within 50 n mi of that city during the last 67 years. Birmingham, Alabama and Jackson, Mississippi aren't far behind.

Huntsville, Alabama 1950-2015 (25)

Birmingham, Alabama (18)

Jackson, Mississippi (17)

I researched one other large city today.......my hometown of Atlanta, Georgia. I knew far fewer violent tornadoes had struck the metro Atlanta area than neighboring states to our west, but the difference is dramatic.......considering Birmingham and Huntsville are less than 150 miles away. Only four (4) violent tornadoes have occurred within 50 n mi of Atlanta since 1950.

I hope you've enjoyed this post.

Yes, Thasnks Perry...
What I m still trying to understand is :
1) Why NO EF 5's have "ever" occured east of I20-59 corridor
2) Never has been documented EF 5 in Georgia

 

[PerryW]

Yes, Thasnks Perry...
What I m still trying to understand is :
1) Why NO EF 5's have "ever" occured east of I20-59 corridor
2) Never has been documented EF 5 in Georgia

It takes perfect atmospheric parameters to create an EF-5 tornado. In far eastern Alabama, Georgia, eastern Tennessee, and the Carolinas......most of the time the extreme ingredients don't come together; why even EF-4 tornadoes are rare.. The April 27, 2011 EF4 tornado at Ringgold is the most intense Georgia tornado aftermath I've seen with my own eyes, with winds 190- 200 mph IMO. The Resaca F4 tornado that occurred on April 3, 1974 was also a very powerful tornado. Dr Ted Fujita's U. of Chicago team surveyed it, and said it was close to F5 intensity.

I fully believe a EF-5 tornado is possible in eastern Alabama and Georgia. Until May 31, 1985, there had never been a F5 tornado in Pennsylvania; why I warn folks to never say never.

 

[MichelleH]

Wonderful information as always Perry! Here's a little tidbit for you...in all my tornado research of Cullman County, Alabama, we have never (knock on wood) been hit by an F5/EF5 tornado. At least as long as records have been kept. Quite a few F4/EF4's though. I've been trying for many years to compile information on one particular tornado that hit the settlement of Hopewell (just north of Hanceville) in the early morning hours of April 8, 1903. Several were killed, including entire families, because they had no warning at all. My interest in this particular tornado is because this is the area where I live...the subdivision of Hopewell Meadows. We don't get a lot of tornadoes in this area, so you would think it would be fairly easy to find the exact storm path. But, I guess since it was 1903, that's where the problem lies. I would really love to know the exact storm path though, since I have lived here my entire life.

 

[PerryW]

Wonderful information as always Perry! Here's a little tidbit for you...in all my tornado research of Cullman County, Alabama, we have never (knock on wood) been hit by an F5/EF5 tornado. At least as long as records have been kept. Quite a few F4/EF4's though. I've been trying for many years to compile information on one particular tornado that hit the settlement of Hopewell (just north of Hanceville) in the early morning hours of April 8, 1903. Several were killed, including entire families, because they had no warning at all. My interest in this particular tornado is because this is the area where I live...the subdivision of Hopewell Meadows. We don't get a lot of tornadoes in this area, so you would think it would be fairly easy to find the exact storm path. But, I guess since it was 1903, that's where the problem lies. I would really love to know the exact storm path though, since I have lived here my entire life.

Here's some info I found about this tornado Michelle
http://www.gendisasters.com/alabama/8269/hopewell-al-tornado-apr-1903

I also created a track map based on information at WSFO Birmingham........a 20 mile long, 200-300 yard wide path from near Hanceville to Holly Pond to Hopewell and Summit.

 

[Helicity]

Perry, your insightful analyses in this and other threads have inspired me to do a little investigation of my own.

This map shows, for each decade, the average location and path length for all violent (F/EF 4-5) tornadoes occurring nationwide within that decade. This was done in ArcGIS using tornado data for 1950-2015 from the SPC’s GIS datapage (http://www.spc.noaa.gov/gis/svrgis/). Within ArcGIS, the Average Directional Mean Tool was used to calculate the average direction, length, and geographic center for each decade. In this case, each line shown is the average violent tornado for each decade in terms of orientation, length, and location.



Each decade is color coded and the average path length (in kilometers) is shown next to the line. The black arrow is the average directional mean for all violent tornadoes within the dataset (an average of the averages, if you will). For reference, the legend indicates decade ‘1950’ is representative of the period 1950-1959, decade '1960' is the period 1960-1969, etc.

I realize that in terms of tornado climatology, decadal study periods are merely arbitrary, but it’s still interesting to see some variation of violent tornado patterns across the US per decade and how short-term synoptic set-ups or generational events may have influenced the averages one way or another.

First, you can see that in general the average location, central Missouri, is sandwiched between the more traditional Tornado Alley and the more southerly Dixie Alley. Also, there’s no surprise that in all cases the average direction is to the Northeast. But check out how far east the 1980s violent tornadoes were compared to the average. Also, the 1960s were much farther north than the average. And of course, thanks to April 27th, the 2010s are by far the longest (so far! Still need 2016-2019 data for a complete decade) in terms of average path length. I am aware of a few of the events that skewed their respective decades (such as the Pennsylvania tornadoes in 1985), but would certainly be interested to hear others’ thoughts on the patterns for each decade.

There are some things to keep in mind with this analysis though, mainly that the number of violent tornadoes in each decade isn’t taken into account. Also, the dataset I used only goes as far back as 1950. If anyone has recommendations on where to find GIS data for violent tornadoes occurring before this date, I’d be happy to add them to the map. I would really like to see how the particularly active 1920s and 1930s might compare.


Hopefully this has peaked your interest and thanks for reading!

 

[MichelleH]

Here's some info I found about this tornado Michelle
http://www.gendisasters.com/alabama/8269/hopewell-al-tornado-apr-1903

I also created a track map based on information at WSFO Birmingham........a 20 mile long, 200-300 yard wide path from near Hanceville to Holly Pond to Hopewell and Summit.

 

[MichelleH]

My computer just went nuts for a minute and I can't find where to delete ^that^ post. Anyway...Perry, thank you so much for that! Especially the map!! (BTW, the article you linked has one fact wrong, and I've seen others that are wrong as well...they say it was in Blount County, when Hopewell is actually in Cullman County.) You are so great! Hope you're feeling good today and praying everyday for you!!

 

[PerryW]

My computer just went nuts for a minute and I can't find where to delete ^that^ post. Anyway...Perry, thank you so much for that! Especially the map!! (BTW, the article you linked has one fact wrong, and I've seen others that are wrong as well...they say it was in Blount County, when Hopewell is actually in Cullman County.) You are so great! Hope you're feeling good today and praying everyday for you!!

Thanks Michelle!

 

[Gawxnative]

Perry... any thought about working on the "mini" Tornado alleys that seem to be fairly common in states...
I know here in GA we have a couple mostly W and NW of Atlanta.
My overall thought would be maybe we have some topographical influenece that help "focus" cells to intensify/maintain themselves. Even if it is empirical data driven, it could help those "downstream" when event develop.

 

[PerryW]

Perry... any thought about working on the "mini" Tornado alleys that seem to be fairly common in states...
I know here in GA we have a couple mostly W and NW of Atlanta.
My overall thought would be maybe we have some topographical influenece that help "focus" cells to intensify/maintain themselves. Even if it is empirical data driven, it could help those "downstream" when event develop.

I believe in Georgia's case, the greater frequency of EF-3 or higher tornadoes across north and northwest Georgia is mostly due to it being a continuation of the Dixie Alley which begins in east-central Louisiana and extends northeastward thru central/ north Mississippi and northern Alabama. A frequent track of sub-synoptic "mesolows" that spawn tornado families (April 4, 1977; March 27, 1994; etc) extends from near Vicksburg, Mississippi to near Gadsden, Alabama......then into northwest Georgia/ southeast Tennessee. My theory is this is a bigger factor in north Georgia strong/ intense tornadoes than tophography.


Dixie Alley -- All EF3 or stronger tornadoes since 1950

 

[David in SW Blount]

Great information! Although, it's pretty unsettling living in the heart of Dixie Alley...

 

[weatherguy]

Here is a old graphic I made back in 2013, one can really see how NW Alabama is a major path for extreme tornadoes:

Very concentrated spot for F5 tornadoes:

 

[apocalyptic_pleasures]

According to this site Huntsville area sees an average of 3 Tornadoes per year. Daleville area sees 2/yr

http://www.homefacts.com/tornadoes.html

There was another site that had similar facts which I cant find now about tornadoes near different cities but it said Daleville got about 1 every 12 years which sounded much more believable.

 

[PerryW]

Here is a old graphic I made back in 2013, one can really see how NW Alabama is a major path for extreme tornadoes:

Very concentrated spot for F5 tornadoes:

Nice maps and information!