What makes a particular area, a perfect path way for Tornado’s?

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I live in Nashville, and we just had a very devastating EF-3 Tornado over night that caused massive damage and lose of life, especially in the East Nashville, or Five Points area.

https://www.tennessean.com/story/weather/2020/03/03/nashville-tornado-path-map-shows-familiar-east-west-direction/4937370002/

This article came up where 2 previous tornado’s (1933 and 1998) had pathed into the same focal point, and I was wondering what about this area makes it perfect for tornado pathing?

In: Physics

8 Answers

Anonymous 0 Comments

Tornadoes reach thousands of feet high. Nothing on the ground really “attracts” them to follow a path. Things like hills and mountains and other large disruptive landscape features can certainly interrupt a rising, spinning column of air, especially if it formed at a lower elevation. And that in turn might mean that a certain topography – a certain landscape – might be more favorable for tornado formation, which in turn might sort of mean that some areas might see more of them, but that’s not the same thing as the question.

Tornadoes generally move from west to east because that is the way fronts/storms usually move. And depending on what time of year it is, the general direction of storms will be more specific in a particular spot, like for example maybe most summer thunderstorms in the upper Midwest are forming along cold fronts sweeping from west-southwest to East-northeast. Given that some of those storms might spawn tornadoes, it’s likely that many paths will have roughly parallel or even similar paths.

It is odd that two of those historical paths have a lot of overlap, but that is how randomness works sometimes. It’s not necessarily a sign that the path there is actually attracting tornadoes or more favorable to them.

Anonymous 0 Comments

Flat farmland to the western areas for fast cool winds to interact with warmer temperature in the area creating the twist and turns to make a Helen hunt and bull Paxton movie.

Edit: living in Ohio anything west of the 23/71 barrier usually experiences more tornadoes due to flat land. Most land to to the East is hilly and the start of the Appalachian mountain range.
Bigger cities have less chance due to expansion into farmlands and the less flat land to grow a twisters. The big cities produce so much heat that it disrupts the air temperatures surrounding it. Most people in eastern areas are less susceptible to high winds.
My sister in law is always freaked out by the weather but she never paid attention in science class or reads about it properly. I school her constantly but it falls on deaf ears.

Anonymous 0 Comments

Better question why are they attracted to trailer parks?

Anonymous 0 Comments

Ooh, I have a follow up question – why is it so unusual for tornadoes to hit urban centers? Is it because they just take up a relatively small % of land? Or is there something about them (tall buildings?) that acts as some kind of tornado-deterrent?

Anonymous 0 Comments

The “heat islands protect urban centers” idea is complete b.s. The reason tornadoes rarely hit urban centers is the one that u/most-likely-a-bot said: they just take up a relatively small percentage of land.

Statistically, in Tornado Alley, a tornado hits the same square mile every 700 years.

As for why there’s a Tornado Alley in the USA in the first place–that is, a large geographical area where tornadoes are more frequent than other large geographical areas–that’s because you have cold and dry air masses coming in from the West and North, which have lost their moisture due to the Rockies, coming into contact with warm, moist air masses from the Gulf of Mexico.

If it weren’t for Gulf moisture we wouldn’t have the breadbasket of the world in the U.S. midwest. We need the Gulf moisture, but it is the main culprit in U.S. tornadoes.

The U.S. South has a fall tornado season in addition to a spring tornado season. That’s because you can get more interaction between warm, moist air masses and cold, dry air masses in the U.S. South in the fall than you can in other parts of the USA.

The USA has more tornadoes than any other continent because we have the wide open space where Gulf moisture can interact with dry, cold air from the Rockies.

As to why St. Louis and Nashville have been hit more than once, that’s a statistical fluke. However, as populated areas grow and take up more geographical area, people come into contact with tornadoes more often. Also, modern radar lets us know about more tornadoes than we probably did before, because many tornadoes in the past may have touched down in unpopulated areas with no radar to tell us about them.

Here are some major urban areas that have had tornadoes: Fort Worth, Brooklyn, Atlanta (Google Georgia Dome tornado) (A basketball game went into overtime saving countless lives, because otherwise the people in the Georgia Dome would have been in their cars) Fort Worth, Salt Lake City, Nashville at least twice, Dallas at least twice, St. Louis at least three times, and Chicago almost got it in 2013 (Soldier Field was evacuated as a game was going on when a tornado almost touched down) Many of these can be seen on Youtube. The Brooklyn one was a baby one and pretty much only busted out store windows. I think it was an F0.

Edited to add: As to why several tornadoes have hit in the same exact place, that’s a statistical fluke. The 2013 Oklahoma City tornado took almost the same path as the Moore tornado of 1999, but there have been plenty of other Oklahoma City-area tornadoes. (It’s one of the areas with the most frequent tornadoes, although Florida wins the prize. Florida tornadoes are often baby ones, though) In KC, the 2003 tornado took almost the same exact path as a 2019 tornado. Those are just statistical flukes. Tornadoes don’t care what geographical features are on the ground, except for mountain ranges which cause moisture to be wrung out of air masses. A tornado doesn’t care if there’s a skyscraper or a trailer park or an open field below it. Again, the reason they seem to hit rural areas more often is there are a lot more rural areas than urban ones. And the reason they seem to hit trailer parks harder is that baby tornadoes will destroy a trailer but won’t destroy a house.

Anonymous 0 Comments

I think it may help to put something into context. There are 30 tornados a year in TN alone on average. That would suggest between 1933 and 2020, there have been approx 2,610 tornadoes in the state, 3 of which had this route. So nashville maybe is more likely to have tornados (middle tn is) but it is hardly some ideal route.

In addition to that, only certain very specific weather patterns will create tornadoes, there are a lot of factors that go into it, and so for the Nashville area, there may only end up being a single set of circumstances (wind direction, pressure, speed, etc) that can plausibly cause tornadoes, and so when those conditions happen, the tornadoes are likely to be in the same area.

I will let some actually meteorologists tell me im wrong though.

https://www.weather.gov/ohx/middletntornadoes

Anonymous 0 Comments

Nothing. Tornadoes don’t follow paths, they go their own way based on the random forces of nature. The fact that this same area was hit three times in nearly 90 years is completely random, and well within the probabilities of tornadoes in March in middle Tennessee.

It might interest you to know that tornadoes DO follow seasonal tendencies. March tornadoes tend to be in the south, Mississipi / Alabama / Georgia / Tennessee. By April and May they are prevalent in Texas / Oklahoma / Kansas / Illinois / Indiana; late May in Nebraska / Colorado / Iowa, and in June in South Dakota / Minnesota / Wisconsin. This is due to the fact that the “dry line” – the meteorological meeting of dry western air colliding with moist air from the Gulf of Mexico – gradually moves north throughout the spring.

Anonymous 0 Comments

*tornadoes

For the most part; a tornado forms when nice warm, moist air collides with cooler air. **It is the temperature difference in the air masses that provide the energy needed**. In the USA, as the Gulf water warms up air masses to the South they tend to flow North and collide with arctic air masses coming South out of the Dakotas from the Arctic VIA Canada.

Most of the winter the Gulf air isn’t warm enough to create such a difference in the air masses. To the West, to some degree, the Rocky Mountains aid in keeping “Tornado Alley”to it’s East. It just so happens that these masses tend to collide over what we know as “Tornado Alley.” As Spring progresses, these air masses shift to the “Midwest” away from the plains as a general trend.