Tornados, what's behind it?

This is a theoretical dissertation. Tornados are on the increase in the mid-west states due to the deforrestation along the Mississippi river valley or delta. The lack of forrests in these areas; ie plowed ground along the Mississippi river are causing thermal uprises which unite with cold air from the north to yield turbulent mixing of hot and cold air. The result is a precurser event to full development of Tornados. I bet that Tornados were less prevalent during the late 18th and19th centuries than they are now. Since the prevailing winds are from the southwest to northeast direction, the majority of Tornados start East of the Mississippi river valley. In conclusion, in order to reduce the amount of Tornados generated, something needs to be done in the plowed ground areas adjacent to the Mississippi river the reduce the thermal updrafts and ultimately reduce the amount or Tornados developed in the Mid-west.

I dunno about that. The reasons the Plains are called that is because they were pretty much plains, that is grassy areas without many trees.
I don't know about the Mississippi theory of yours, but I though Tornado Alley was further west, Texas northward.
They must have been fairly common in 19th century life--didn't folks have "storm cellars"?

In conclusion, as the earth has warmed over the past hundred and fifty years, during its recovery from the global chill of the Little Ice Age, there has been no significant increase in either the frequency or intensity of stormy weather in North America. In fact, most studies suggest just the opposite has likely occurred. This observation -- coupled with the fact that storminess in many other parts of the planet has also decreased or held steady as the world has warmed -- thus suggests there is no data-based reason to believe that storms anywhere will become either more frequent or more intense if the world warms a bit more in the future.

In conclusion, as the earth has warmed over the past hundred and fifty years, during its recovery from the global chill of the Little Ice Age, there has been no significant increase in either the frequency or intensity of stormy weather in North America. In fact, most studies suggest just the opposite has likely occurred. This observation -- coupled with the fact that storminess in many other parts of the planet has also decreased or held steady as the world has warmed -- thus suggests there is no data-based reason to believe that storms anywhere will become either more frequent or more intense if the world warms a bit more in the future.

www.co2science.org...

Originally posted by abajootz
This is a theoretical dissertation. Tornados are on the increase in the mid-west states due to the deforrestation along the Mississippi river valley or delta. The lack of forrests in these areas; ie plowed ground along the Mississippi river are causing thermal uprises which unite with cold air from the north to yield turbulent mixing of hot and cold air. The result is a precurser event to full development of Tornados. I bet that Tornados were less prevalent during the late 18th and19th centuries than they are now

I do believe you'd lose that bet.

For one thing, weather patterns around these parts move west-to-east... not east-to-west. This means that there's nothing in Louisiana and north that's going to affect Texas and north. At least, I don't see "massive Amounts Of Suck" listed in your theory, there.

Tornados are more frequently reported now... but that's because of more people and better equipment. They have been spotted on every continent (except Antarctica, which is basically an ice desert (little precipitation))

Since the prevailing winds are from the southwest to northeast direction, the majority of Tornados start East of the Mississippi river valley. In conclusion, in order to reduce the amount of Tornados generated, something needs to be done in the plowed ground areas adjacent to the Mississippi river the reduce the thermal updrafts and ultimately reduce the amount or Tornados developed in the Mid-west.

I don't see the connection. Doesn't match the weather dynamics. Remember, you have to have thunderstorm conditions (not just a warm area; rain is needed) for a tornado.

I could be wrong about this (false memories, poor observations, etc), but growing up in the Chicago area as a youngster I recall dreadful winters with lots of snow and frequent subzero temps, and fairly active tornadic seasons, as well.

Then I moved west, and it seemed a few years after that the seasons changed in that they were not nearly as extreme. Winters were much milder, not much snow, warmer temps, and tornados pretty much stayed to the southeast. I have a brother who stayed in the Chicago area and lived there for years after I left, and he told me that the seasons really did change.

A few years ago it seems the seasons changed back somewhat and have become rather harsh again. As a matter of fact, it seems the last few years the tornadic weather has moved north.

Maybe I'm imagining it, but there appears to be a cycle. At least during my lifetime. So, I'm not so sure about the theory set forth here. There was a time in my memory when it was pretty tornadic up north.

Like Byrd said forming of tornados isn't so simple process... in fact currently it's not even possible to say exactly will some thunderstorm form tornados.

Here's some sites you might want to check.
ww2010.atmos.uiuc.edu...(Gl)/guides/mtr/svr/torn/dgr/evsch.rxml
www.erh.noaa.gov...
snow.ihs.ncu.edu.tw...
www.extremeinstability.com... (these images are harcore stuff)
I don't have now time to search more but use words like supercell and tornado and Google should give you lot of links.


"Hook" in radar picture is indicator for good change of tornados, but neither is that sure sign of it.
Of course if radar shows it on thunderstorm near you, you might want to start watching it.



Doesn't it look like hurricane?



Ouchhhh!

Doesn't the increase in tornado-producing thunderstroms in the US have some relation to the 'El-Nino' phenomenom? I believe its something to do with the temperature of the Pacific Ocean, possibly affecting the temperature of these hot winds that are needed to start a violent thunderstorm. I think I have a documentary on video somewhere...

jimi

Originally posted by jimi
Doesn't the increase in tornado-producing thunderstroms in the US have some relation to the 'El-Nino' phenomenom?

Yeah, it affects to large scale weather patterns.
Best tornado weather is when there cold&dry air coming from north and warm&humid air coming from south. (generally from those directions)
When these air masses collide colder and heavier air forces warmer and lighter air to to rise condensing water and leading to formation of clouds.


"Normal" thunderstorms form when sun heats ground causing air to heat and rise wich then forms those clouds. This clearly need warm and humid weather and heat from sun. (but when two different airmasses collide they can produce thunderstorms even at winter)

I have been in Texas my whole life and I haven't noticed an increase, so to speak, in tornadic activity ... just better informed people, better news, and FAR better equiptment .... we have advanced in our detection. I don't really think we are having more ... just that we are more aware.


*Zerinity*

Originally posted by E_T

Originally posted by jimi
Doesn't the increase in tornado-producing thunderstroms in the US have some relation to the 'El-Nino' phenomenom?

Yeah, it affects to large scale weather patterns.

check into the American Meterological Society www.ametsoc.org...

global warming and Gulf Stream currents in addition to El Nino are in play.
scan this site;

www.luisprada.com...

>another link>> //www.spiritofmaat.com/announce/ann_dryicecc.htm

[edit on 6-12-2004 by St Udio]

Originally posted by Zerinity
I have been in Texas my whole life and I haven't noticed an increase, so to speak, in tornadic activity ... just better informed people, better news, and FAR better equiptment .... we have advanced in our detection. I don't really think we are having more ... just that we are more aware.


*Zerinity*

Very well said! There are so many times when tornados are being reported strictly because they were observed on radar. It used to be the only way a tornado was mentioned if it was seen with the naked eye.

We just had tornadoes in Olla (where there were tennis ball-sized
hail!) and in Slidell, Louisiana.

Here's a site with easy-view tornado stats for how many
each year and per each state for the US:

www.geocities.com...

This site tells about all the tornadoes which have occurred in the US
in the twentieth century:

www.disasterrelief.org...

Lastly, the tornado project online:

tornadoproject.com...