Talk:Tornado/Archive 4

Archive 1

Archive 2

Archive 3

Archive 4

Archive 5

Archive 6

Previously commented-out text

I just liberated long portions of text that were commented out because they were unreliable. Unfortunately, no one can fix those if no one can see them. I tagged those for accuracy problem; we'll have to parse through these sections and find references and separate good info from bad. -- Beland 05:31, 6 December 2006 (UTC)

Splitting

I have split off two articles, one for climatology, and one for damage and intensity. The todo list and some comments above may now apply more to the subarticles than this one, per se.

This article is still 51K long, which is longer than recommended. Some material is probably redundant between sections, and could be cut down. Other material could be moved to subarticles, making the summaries left behind here more concise. -- Beland 06:12, 6 December 2006 (UTC)

This is one project I have been procrastinating majorly on. I did manage to fork out a few articles (mostly ones that already existed), but yes it has been cumbersomely long recently. Hopefully once winter break starts up I will have time to do more. -Runningonbrains 15:20, 6 December 2006 (UTC)

It looks to be manageably long now, especially for an article with such breadth. A lot of the 52K is photos, references, and external links. I suppose it could be cut a bit more, but also a few more things could be added. I'll see what I can do over the next few weeks. -Runningonbrains 23:52, 11 January 2007 (UTC)

UK - world's tornado alley?

I've heard it oft quoted but NEVER with a source, that the UK gets more tornadoes per square km than any other country in the world... Now, I've looked but I can't seem to find anything but hearsay, any confirmation? —The preceding unsigned comment was added by 86.131.159.19 (talk) 01:08, 9 December 2006 (UTC).

Shear funnel vs. Cold air vortex

Really, is there any difference? -Runningonbrains 04:30, 23 December 2006 (UTC)

• Yes they're different phenomena; due to scant sources (and lack of time), I've not addressed this, but given that the article is now a FA, I will explicate it as soon as possible. Evolauxia 00:54, 4 April 2007 (UTC)

Vandalism on Tornado and Thunderstorm

There is a bit of vandalism here, and as I have no admin powers, I can't efficiently revert it. Could someone take care of this? —The preceding unsigned comment was added by Cormallen (talk • contribs) 14:56, 11 January 2007 (UTC). (sorry for the unsigned comment)

GA Passed

Congrats, it's a Good Article! :-) For "next up" projects I would reccomend expansion of the Climatology section, and also addition of the Enhanced Fujita Scale. - Aerobird ^{Target locked - Fox One!} 01:14, 18 January 2007 (UTC)

UK - World's Tornado Alley?

I have lived in the UK all my life and I've never personally witnessed a tornado myself, but I've seen recent news reports about tornadoes and a documentary that confirms that the UK has, on average, 33 tornadoes a year. That's more than Central United States, it's just that most British tornadoes occur out in the countryside where they don't do too much damage and probably don't last as long.

The United States can be said to have the most of the severe tornadoes, but the UK appears to have the most overall. —The preceding unsigned comment was added by Rabbitlover (talk • contribs) 19:32, 18 January 2007 (UTC).

Actually, it's not as much as the central US. Oklahoma, for example, has an area of 181,200 square kilometers, and averages 58 tornadoes a year[1], about 0.00032 tornadoes per square kilometer per year. It is also believed that the actual number is higher, as most of the state's population is in sprawling urban and suburban areas like Oklahoma City and its suburbs, so many weak tornadoes go unobserved. The United Kingdom has an area of 244,800 km², with an average number of officially reported tornadoes of 33. However, TORRO believes the actual number to be around 50, so i'll use that. This leads to an average of 0.0002 tornadoes per km² per year, only about 60% of Oklahoma's official count.

The reason they get more coverage may be that weak twisters are big news in the very densely populated UK (243 people per km²), while not as important in a rural state like Oklahoma (30.5 per km²). The same thing happens where I live in New England, where even occasional weak tornadoes are big news, as someone is bound to see them.

As a side note, I believe that Netherlands has the most tornadoes per area per year in Europe. I dont know the numbers though. Hope all this was useful! -Runningonbrains 20:56, 18 January 2007 (UTC)

The only state in the USA that hasn't been reported as having tornadoes is Alaska. I'm pretty sure. The most tornadoes in tornado alley are in Texas and Oklahoma.

I have added the claim about the UK in the Climatology section, with external citation. I have seen two tornadoes in the UK, but neither was very big or long lasting. Neither caused any damage. Northfold 16:26, 24 May 2007 (UTC)

The NL has more per area than any US state. I've reinstated the facts with the best data available in regard to the UK. There have been tornadoes recorded in Alaska, however, that's infrequent. Part of that is the extremely small population density. Evolauxia 14:25, 1 June 2007 (UTC)

Anon Vandalism...

...Has been getting rediculous. I'm fed up, so I put the page up for semi-protection. -Runningonbrains 16:38, 26 January 2007 (UTC)

Very Helpful!

I happen to live in tornado alley (TX) and I thought this was very useful info. I also love this site!! I am in 7th grade and doing a project for science over avalanches. This website helps with everything!! —The preceding unsigned comment was added by Bandgeek3377 (talk • contribs) 01:12, 2 February 2007 (UTC).

Torndao alley

The article on Tornado alley appears short enough to add to this article. I don;t know enough of the history about these two seperate articles to know if they where prevoiusly on one page. If not how about adding the tornado alley atricle to the see also section. There are a few links here and there but they could easily could be missed. Natural number is e 18:01, 28 February 2007 (UTC)

This article is almost too long as is, and Tornado alley stands on its own just fine. My next project is to get all the sub-articles of Tornado to GA-class, so I'd definately leave it as is. As for being in the see also section, it is already linked to in the climatology section, so I'll leave it out. Thanks for your input! -RunningOnBrains 22:43, 28 February 2007 (UTC)

Tornado Myths

This section says

"Similarly, an old belief was that the southwest corner of a basement provides the 
most protection during a tornado. In actuality, the safest place is in the northeast 
corner of an underground room"

I believe this is inaccurate, as the safest location would vary depending on the approach direction of the tornado. It seems to me that the safest place in the building would certainly be underground, but in whatever corner is closest to the tornado as it approaches. The damage would be least there, since the tornado would cross it first and therefore have the least time to "dig down" to people sheltering there.

Can anyone validate or invalidate the claim that's on the main page?

*Septegram*Talk*Contributions* 13:40, 12 March 2007 (UTC)

It's true, as seen in the reference. You can also find it online here. You are right though, it does depend on the direction of the tornado's approach, I have changed the wording accordingly. -RunningOnBrains 18:38, 12 March 2007 (UTC)

Yeah, I found that link too; I just haven't had time to get back here. Thanks for taking care of it.

*Septegram*Talk*Contributions* 19:35, 12 March 2007 (UTC)

I have been told that if you place a jar of water outside, it will freeze during a tornado. Is this true?

No. -RunningOnBrains 21:32, 19 March 2007 (UTC)

No single actionable advice is applicale in all cases, so we must advise what is best in the most situations. In general, the center on the lowest floor with as many walls between the outside is the way to go. Reinforced rooms like bathrooms with pipes and heavier construted walls and floors are better than other rooms. Also, if possible, a heavy bench or other form of protection is advisable against falling debris. Although the safest place usually is the basement, on occasion people are killed by falling chimneys or other debris when they may have surived otherwise (in most cases, they would have been safer below ground than above ground, however). Debris tends to collect in the corners of basements, so no corner is preferable in the majority of situations. The as many walls in the center in a sturdy room advice is applicable when a below ground shelter is not available. Evolauxia 12:49, 21 March 2007 (UTC)

Restructured the first half of the article

The flow of the text was all over the place. Moved some of the sections originally inside definitions to their respective sections inside, and after, life cycle. I know this type of reorganization is unusual for an article of GA, let alone FA status, but I think its elevation to FA status was premature. It's in no better shape than tropical cyclone right now. Thegreatdr 21:36, 30 March 2007 (UTC)

While I do appreciate the effort, I believe the new format is much worse than how it was. It now seems disjointed and choppy, with lots of white space. What exact objections did you have to the old way? -RunningOnBrains 00:15, 31 March 2007 (UTC)

In the old version, the definition section was huge, and covered aspects such as word derivation, and other related phenomena. Now these sections are parsed out and are simpler to find for someone looking specifically for supercell, funnel cloud, or the word origin for the term tornado. The former definition sections are now located closer to their first use in the life cycle section of the article so that the article flows smoother. If I remember correctly, this is how textbooks normally order things.

Even after the edits, I'm still not thrilled about the location of the multiple vortex tornado and tornado outbreak blocks. They still don't appear to flow logically. Multiple vortex tornado should be somewhere near the end of the life cycle section with some explanation on how their form (if known). There needs to be more with the tornado outbreak. Perhaps it needs its own subarticle. The white space after Word Origin and Tornado Outbreak sections is unneeded, but I'm not sure how to remove it. Does citeweb cause it? There don't appear to be any clearing sections (div's) after those articles. Thegreatdr 13:04, 31 March 2007 (UTC)

Old or new?

Perhaps there should be a vote as to whether other people involved in the editing of the article prefer the current look of the article or the former look. If enough people like the former look, it can be reverted easily enough. Thegreatdr 13:12, 31 March 2007 (UTC)

• Old: Tornado achieved featured article status due to Runningonbrains hard work. I suggest we let it rest for a month before making major changes. --Kevinkor2 18:34, 31 March 2007 (UTC) P.S. I have created User:Kevinkor2/Tornado for people to work on while the main article rests.
  • While I wouldn't want to seem in violation of WP:OWN, I do believe that changes should be less drastic, otherwise a Featured Article Review might be in order. Would you be opposed to reverting to the earlier version, and working slowly from there, with discussion here to help collaborate. We could adapt the article to be more structured without leaving it disrupted while we make changes. -RunningOnBrains 23:39, 31 March 2007 (UTC)
    • Keep with revisions (I'm not averse to old with revisions either). I always wondered why definitions where italicized instead of the standard bolded. Anyway, using smaller headlines (or the "; " function) to break it up and make things easier to find without making the article choppy or contain excessive white space is advisable. I do like the clearer division of supercell relationship and listing of non-supercell circulations, my main issue with the new layout are multiple vortex tornado, satellite tornado, tornado family (and cyclic tornadogenesis), and tornado outbreak which are unclear and disorganized, those should be cleaned up if we don't revert. Word origin should probably be changed to etymology. Evolauxia 23:59, 3 April 2007 (UTC)
      • That would be much more agreeable. The multiple section headers are extremely disruptive. I had actually forgotten about the semicolon, that should work very nicely. -RunningOnBrains 05:07, 4 April 2007 (UTC)
        • Sounds like a good compromise. I know there was concern over the white space, and it seems like what you are suggesting addresses both my concern and Runningonbrains concerns. Personally, I think the multiple vortex tornado and tornado outbreak are ill placed. Maybe they could be after the life cycle section, with a fuller description, or even better, with their own subarticles so tornado doesn't become unwieldy. Thegreatdr 20:41, 5 April 2007 (UTC)

Restructured the restructuring

Just finished a minor overhaul of the first half of the article. What do people think? Better, worse, neutral, or none of the above? -RunningOnBrains 10:16, 6 April 2007 (UTC)

Definitely an improvement. I also broke up multiple vortex tornado, satellite tornado, and tornado family to separate paragraphs. Evolauxia 00:39, 7 April 2007 (UTC)

Just when we thought I increased the white space. =) I like the fact characteristics was moved up...was thinking of making that change last week (that was the biggest improvement). In a way, it makes some sense to separate out types of tornadoes. It just occurred to me that the article is missing any discussion of the formation of non-supercell tornadoes, which I remember placing in some article in the past (maybe it was waterspout). It needs at least a paragraph on that. Thegreatdr 11:37, 7 April 2007 (UTC)

Replacement of funnel cloud aloft photograph and revisions

The current photograph, as well as those in the Commons are not good examples. The rest are all tornadoes without full condensation from ground to cloud but with readily apparent swirling debris at the surface, whereas the currently used photograph is probably also a tornado but the likely surface circulation is obscured.

Perhaps some text should be added denoting funnel cloud aloft from funnel (condensation) cloud of a tornado. There is little difference between a true funnel cloud (rooted in boundary layer and associated with mesocyclone) aloft and a tornado ("funnel cloud on the ground"), the emphasis on such stark divisions hammered in for years created confusion, misidentification, and was counterintuitive (and indeed is being relaxed with much more emphasis on watching under funnel clouds and rotating wall clouds in spotter training). I would probably introduce the catch all term condensation funnel and explain the differences, as well as add a little more on debris (the emphasis is on condensation cloud, though debris effects are described later in the appearance section). I will also revise shear funnel (a kind of mid-level or high-based funnel, i.e. not rooted in the boundary layer) vs. cold-air funnel, they are not the same thing. I think this should be done in the tornado article as it's important but should be succinct with greater detail in the funnel cloud article. Evolauxia 00:45, 4 April 2007 (UTC)

Tornadic supercell diagram

I could translate and redraw this diagram, however, what are thoughts on this NSSL digram? Evolauxia 02:05, 4 April 2007 (UTC)

That NSSL diagram would be great, if not in this article definately in supercell. -RunningOnBrains 05:09, 9 April 2007 (UTC)

Photos of other tornado phenomena

In tweaking the section on types of tornadoes, I thought of looking for photographs to illustrate them. We currently have a decent public domain photo of a tornado family in the Goshen, IN tornado from the 1965 Palm Sunday Outbreak, though other examples exist such as Hesston-Goessel, KS from March 1990 and another from 1993. I've yet to find others, some of which may illustrate it better, and also show how merging tornadoes can make it especially difficult to discern continuous tornadoes from tornado families in post (damage) analysis. There is a great example of a satellite tornado near Chickasha, OK during the 3 May 1999 outbreak, however, I've not yet found a fair-use or public domain example. Other examples are out there too. Multiple vortex tornado and features of tornado vortices are more examples to locate, though the latter would require textual explanation of vortex features and perhaps its own article. Evolauxia 00:49, 7 April 2007 (UTC)

I don't like the Twin tornadoes example...it is on the blurry line between multi-vortex and separate tornadoes. I'll look for a better one, there's gotta be one out there. -RunningOnBrains 05:35, 9 April 2007 (UTC)

I don't particularly like it either so I brought up finding alternatives. We know for sure they are completely separate tornadoes, we have photos of both before and after that famous still was taken, but at that time it *is* ambiguous in the photograph. Video illustrates some things much better, notably mergers, subvortices and other transient vortex feautures. Other photographic examples exist, finding good fair use examples will be the trick. Evolauxia 18:51, 9 April 2007 (UTC)

Perhaps a series of three photos would work.--Kevinkor2 19:08, 9 April 2007 (UTC)

I don't personally have the expertise to do this, but I know wikimedia supports .gif animations, so if someone were able to convert a video into a simple .gif it would be perfect, as an alternative to just linking to videos. —The preceding unsigned comment was added by Runningonbrains (talk • contribs) 19:58, 9 April 2007 (UTC).

The Cause of a Tornado

It has recently been argued that the spiral patterns in the weather are not caused by the Coriolis force in the normal sense. That argument was swiftly suppressed. Yet on these pages, it is acknowledged that a tornado is not caused by the Coriolis force in the normal sense. So tell me please, how does a tornado differ fundamentally from a large scale cyclone in so much as that one can be caused by the Coriolis force and the other can't? And if a tornado is not caused by the Coriolis force, what does cause it? David Tombe 8th April 2007(222.126.33.122 09:11, 8 April 2007 (UTC))

1. Neither one is 'directly' caused by the Coriolis effect. However, the Coriolis effect does affect the direction in which the vortex will normally rotate, just as it causes the planet's prevailing wind patterns overall to be oriented in bands of opposite-direction winds in an east-west orientation. What causes the tornado's rotation is convective activity causing a horizontal rotor in the storm, which is then tipped to the vertical by the storm's inflow updraft and outflow downdraft. Rdfox 76 01:53, 9 April 2007 (UTC)

We know that neither one of them is directly caused by the Coriolis force. We know that there are alot of factors involved. There are radial forces, axial forces and tangential forces.

The tangential forces cause the cyclonic effect and this effect is clearly determined, at least indirectly, by the Earth's rotation. What can this effect possibly be if it is not the Coriolis force?

The main article says that the Coriolis force is not directly involved in a tornado. How can this be so? Explain how it can be indirectly involved. David Tombe (203.114.102.58 12:25, 10 April 2007 (UTC)) 10th April 2007

One of the leading explanations for the origin of low-level rotation in supercell thunderstorms that provides the rotation from which tornadoes develops involves the parent storm redistributing precipitation to the rear of the storm because of the rotation of the parent storm. The sense of rotation of the parent storm comes from the vertical shear of the environmental winds. The winds at low-levels typically have a component from the equator, bringing in the warm, moist low-level air, and have winds aloft from the west. The environmental wind shear through the deep troposphere and resultant winds aloft are related to the thermal wind. The low-level winds are typically found east of low-pressure systems in mid-latitudes. The sense of both the winds aloft and the low-level winds, then, are results of processes that are related to the rotation of the earth. If you do a formal analysis of the vorticity budget for a tornado, or even the parent thunderstorm, you find that the Coriolis term is small(O~10^-4) compared to the environmental wind shear term (O~10^-2). Thus, even though you can ignore the Coriolis term in models of thunderstorm rotation, as has typically been done in numerical simulations of supercells, the arrangement of the vertical wind profile is what it is because the earth rotates. If you put the Northern Hemisphere typically-observed clockwise curving hodograph into a numerical thunderstorm model and assume a horizontally homogeneous environment, the modelled storm will rotate counterclockwise even with the Coriolis term set to zero. Low-level rotation in that model storm will also be counterclockwise because of processes that go on inside the storm resulting from the sense of rotation of the parent storm. The fact that the NH severe storm hodograph curves clockwise with height, though, is related to the sense of rotation of the planet. Hebrooks87 14:00, 10 April 2007 (UTC)

Thanks for the reply. But I can't help thinking that there is a tendency to make things overly complicated when analyzing these kinds of phenomena.

Right now we are specifically talking about what causes the cyclonic nature of a tornado. There are two indisputable facts regarding the cyclonic nature of a tornado.

(1) The vorticity must be caused by some kind of tangential forces.

(2) The fact that the vorticity direction in each hemisphere corresponds to that of the larger cyclones means that it must be some how related to the Earth's rotation.

What can these tangential forces possibly be if they are not the Coriolis force? Yet the main article is telling us that the tornado is not directly caused by the Coriolis force.

I would suggest that the vorticity of a tornado must be directly caused by the Coriolis force because it can be nothing else.

This of course opens up another major problem, but before we can tackle that, we need to have some kind of consensus as to what is causing the vorticity in a tornado. David Tombe 11th April 2007 (61.7.158.94 06:26, 11 April 2007 (UTC)).

The Coriolis force does affect the tornado, but the the effect is infinitesimal at such scale, as Brooks stated. By far, most of the tornado rotation results from processes in the thunderstorm and the environment. The thunderstorm's rotation is induced by the updraft interacting with vertical wind shear. Those environmental winds occur due to larger processes that are strongly influenced by the Coriolis force. Thus, there is an indirect effect of Coriolis force through the processes that are much more responsible for tornado rotation. Evolauxia 08:46, 11 April 2007 (UTC)

Evolauxia, what you have said above does not make any sense. Over 95% of tornadoes are cyclonic. That means that their direction of rotation must ultimately be traced back to the Earth's rotation. And what other tangential forces can you think off other than the Coriolis force?

The conclusion can only be that the direction of rotation of a cyclonic tornado is caused by a Coriolis force which is ultimately traced back to the Earth's rotation.

Your mistake is that you are looking to the wrong mechanism to account for the Coriolis force. You are looking to the fictitious effect that is directly linked to the Earth's rotation. You are ignoring the possibility of intermediatory mechanisms. David Tombe 11th April 2007 (61.7.161.229 09:30, 11 April 2007 (UTC))

There are steps connecting the rotation of tornadoes to Coriolis force, so yes, in that way it can be traced back to Coriolis but the component directly involved in tornado rotation is, again, infinitesimal; that's basic physics (see Rossby number). That the Coriolis term is inconsequential is known, though the process of tornadogenesis is fundamentally that of stretching and tightening of low-level vorticity (in buoyant air) and the details of that we can only hypothesize currently. There are other processes occurring which would be very involved to get into, but do involve movements of air (especially of differing thermodynamic properties). Large-scale low pressure systems invariably(*) rotate cyclonically, so if Coriolis is also the force causing cyclonic rotation of tornadoes, why are there anti-cyclonic tornadoes, especially of the non-mesocyclone variety? I'm using basic physics of Coriolis force, there can be no other intermediary mechanism directly causing tornado rotation; and by virtue of being intermediary, any such mechanism is indirect. Perhaps there is a misunderstanding of semantics? Evolauxia 11:31, 11 April 2007 (UTC)

As you say, there are indeed anti-cyclonic tornadoes. However well over 95% of tornadoes are cyclonic. This clearly indicates that the rotation of the Earth is a factor in the cyclonic tornadoes. It would be far too much of a coincidence otherwise. And if it is not the Coriolis force that is causing the tangential effects and hence the rotation, then what is it?

It strikes me that you are overlooking some very basic facts and preferring to seek a complex explanation of which you admit above that the details can only currently be hypothesized.

You seem to think that the Coriolis effect in a tornado would be negligible, but you are basing this assumption on the theory surrounding the fictitious Coriolis effect of the kind that causes the Foucault pendulum to precess. It cannot be that effect because tornadoes are visible from outside of the Earth's rotating frame of reference. Did you consider the hydrodynamical Coriolis effect vXH, where H is vorticity, in Maxwell's, Bernoulli's or Tesla's sea of tiny vortices? Wouldn't these tiny vortices align solenoidally to create the Earth's magnetic field? Did you consider that the cyclonic effect might be caused by the Lorentz force? David Tombe 11th April (61.7.161.145 15:40, 11 April 2007 (UTC))

No, we're neglecting it because in a scale analysis of the equations of motion, it's a small term. The sense of rotation is determined by the sense of rotation of the parent storm. The parent storm's rotation is determined by the environmental wind shear (ignoring the left-movers from splitting storms), which in turn is related to where the equator is compared to the poles. Numerical models that set the earth's rotation to zero and have none of the electromagnetic forces are perfectly capable of showing the origin of rotation. If you flip the hodograph over, the storm rotates the other direction. See Helicity (fluid mechanics) for the relevant physical quantity associated with the origin of storm rotation. Hebrooks87 12:11, 12 April 2007 (UTC)

You are totally ignoring the obvious. If over 95% of tornadoes rotate in sympathy with the Earth's rotation, then the two phenomena must be interconnected. The direction of rotation must be caused by a Coriolis force force that is in turn caused by the Earth's rotation.

It is quite wrong to sate in the main article that the direction of rotation of a tornado is not directly caused by the Coriolis force as is the case in the larger cyclones. The mechanism that determines the direction of rotation has to be the same in both cases. David Tombe 13th April 2007 (61.7.159.67 07:08, 13 April 2007 (UTC))

You are totally ignoring the obvious. No one has said that the two phenomena are not interconnected. In fact, in both of my replies, I said that they were. Unfortunately, you seem to be refusing to read the explanation. I will try one more time.

The connection is indirect. The sense of rotation of the thunderstorm results from the shape of the hodograph. The shape of the hodograph in conditions which produce thermodynamic profiles which will support thunderstorms (warm, moist air at low levels) typically requires flow at low levels from the equator. The winds aloft in mid-latitudes flow from the west because of the thermal wind relationship, which involves the Coriolis force. Winds at the surface from the equator and winds aloft from the west lead to cyclonic rotation (counterclockwise in the Northern Hemisphere, clockwise in the Southern Hemisphere.) The source of the rotation is the enviromnental wind shear (change of the winds with height). Again, see Helicity (fluid mechanics) for the relevant physical quantity. You can write helicity as the dot product of velocity and vorticity. The planetary vortcity is ~1% of the vorticity associated with the wind shear. The direct connection of storm rotation is to the wind shear. The sign associated with the wind shear is indirectly associated with the planetary rotation because the mid-to-upper tropospheric wind direction is because of the earth's rotation. The lack of direct relationship with the Coriolis force is seen in simple scale analysis as shown in the Rossby number, predicted by more sophisticated theory (e.g., Davies-Jones work on streamwise vorticity, or the Rotunno and Klemp analysis), and from numerical models of thunderstorms over the last 30 years which have typically not included a term for planetary rotation and still produce rotating storms. Hebrooks87 11:41, 13 April 2007 (UTC)

Part of the problem here is that anybody has even bothered to introduce the issue of whether the cause is direct or indirect.

The direction of spin of the tornado is determined by the direction of spin of the Earth as is proved in more than 95% of cases. That is essentially the end of the story. If the Earth wasn't spinning, it's questionable whether or not we would even have tornadoes at all. And if we did, I certainly wouldn't expect 95% of them to spin in one particular direction.

In the main article, the role of the Coriolis force in tornadoes is totally played down by stating that 'unlike in the case of the larger cyclones, the Coriolis force is not directly involved in tornadoes'.

As far as I can see, the role of the Coriolis force and the Earth's rotation in tornadoes is no different than it is in the case of the larger scale cyclones.

The main problem in all of this begins with the official explanation for the direction of spin for the larger scale cyclones. It has been correctly attributed to the Coriolis force due to the Earth's spin, but for the wrong reasons.

Those reasons become obviously wrong when applied to the specialized case of the tornado. This leads to your total confusion and to why you have to begin to play the Coriolis effect down as regards tornadoes.

It is your understanding of Coriolis force that is the ultimate problem in all of this. You see it as a purely fictitious effect which could not possibly explain something as real as a tornado. That is where your confusion sets in. You are overlooking the fact that the Coriolis force is actually a very real term in hydrodynamics given by the expression vXH, where H is vorticity. It is part of the Lorentz force of electromagnetism. You are ignoring the role of the Earth's magnetic field in meteorology, and you are looking to a fictitious effect that can explain artifacts such as the precession of the Foucault pendulum, to explain very real phenomena such as a tornado. David Tombe 13th April 2007 (61.7.150.140 12:48, 13 April 2007 (UTC))

I'm afraid you're wrong, sir. Meteorology *IS* hydrodynamics--specifically, fluid mechanics. Vorticity is well-understood and recognized in meteorological circles. At no point is anyone saying that the Coriolis force has no effect on the rotation of the tornado, merely that it has minimal DIRECT effect on its rotation. The fact that mathematical models that fail to incorporate the Coriolis force's direct effect on a storm still generate rotating supercells by itself shows that the Coriolis force is NOT the primary source of a storm's rotation.

In any event, the Coriolis force would be of minimal effect over the relatively narrow width of a thunderstorm cell--per thunderstorm, single supercells grow no wider than 15 miles, or about 24 kilometers (and please, no debates over my rounding it off to the nearest kilometer, because the 15 miles figure is an approximate one, anyway). According to Earth, the meridional circumference of the planet is 40,007.86 km, meaning that the distance from the equator to the pole is essentially 10,002 km. This means that the distance between the southern and northern edges of the cell is approximately 0.24% of the distance between the pole and equator, resulting in negligible difference between the surface linear speeds of the planet at each end of the storm, and thus negligible Coriolis force. According to Coriolis_force#Coriolis_in_meteorology, in fact, the atmospheric effect of the Coriolis force is generating cyclonic rotations of approximately 100 km radius in the mid-latitudes, rotating at a rate of one rotation every fourteen hours.

What the Coriolis force does do to the supercell is define the typical directions of the inflow air due to thermal wind shear. This may help define the direction in which the storm itself rotates (does anyone have any data on the frequency of cyclonic versus anticyclonic storms generated by models that neglect the Coriolis force?), but does not directly cause the rotation itself. The rotation occurs due to the interaction of both thermal and velocity wind shears. While the Coriolis force has an effect on the direction of the cell's rotation, it isn't the direct source of it. And since there are anticyclonic supercells, obviously, the Coriolis force isn't the sole determining factor behind the supercell's direction of rotation.

As for alleged electromagnetic effects on the storm's rotation, even fewer mathematical models take any possible electromagnetic forces into account than take the Coriolis force into account, yet they still produce rotating storms, mesocyclones, and tornadoes. Just as with the Coriolis force, the fact that ignoring this potential factor doesn't prevent the formation of supercells indicates that it is a negligible factor in the rotation of the storm. Rdfox 76 14:07, 13 April 2007 (UTC)

If the Coriolis force, due to the Earth's spin, determines the direction of spin in at least 95% of tornadoes, how can you then state that its effect is negligible? David Tombe 14th April (61.7.159.15 06:09, 14 April 2007 (UTC))

Simply put, the Coriolis force's effect on the tornado is negligible because the mathematical models ignoring it say that, without it, tornadoes would form anyway. The direction of spin is essentially immaterial; it's whether or not you have spin at all. As pointed out by Hebrooks87 above, the Coriolis force provides less than 1% of the storm's rotation, which is an insignificant factor when compared to the environmental wind shears that generate the majority of the storm's rotation.

Think of it this way... the storm's rotation is comparable to the flow of water running down a sloped board with a splitter in the center, which can be tipped one degree to either side. The rate of spin is equivalent to the speed at which any given drop of water is flowing along the board; the direction of spin is equivalent to which side of the splitter it goes. If the board isn't tipped in either direction, as in a system with no Coriolis force directly affecting the storm, then approximately 50% of the water will go on either side of the splitter. Add in one degree of side-tilt, roughly approximating the magnitude of the Coriolis force on the storm, it won't affect the speed of the water, but it'll make at least 95% of the water go to one side of the splitter.

In short, yes, the Coriolis force affects the storm's rotation, tending to provide a little impulse that tips the balance towards cyclonic rotation instead of anticyclonic rotation. However, to say that it causes tornadoes is incorrect, because the mathematical models show that tornadoes would form just as frequently without it as they do with it. Rdfox 76 11:30, 14 April 2007 (UTC)

There has to be something that triggers off the spin in the first place. It would seem that in the case of water draining out of a sink hole that it is a balance of random currents. This leads to a fifty percent chance that the vortex will be cyclonic.

However in 95% of tornadoes it is the spin of the Earth that determines the direction of spin. I can't see any fundamental difference in the role of the Earth's spin as regards tornadoes on the one hand and as regards the larger scale cyclones on the other hand. Yet you say in the main article that unlike in the case of the larger scale cyclones, the Coriolis effect is not directly involved in tornadoes.

It strikes me that the Coriolis force , due to the Earth's spin, plays exactly the same role in each of the two phenomena. It determines the direction of spin.

But if we were to depend on the fictitious Coriolis force as it applies to the Foucault pendulum, we would not get any effect at all because the atmosphere is entrained with the Earth's rotation. We need to find an initial source of Coriolis force that is related to the Earth's spin and that is real. We must look to the Lorentz force in the magnetic field. You say that it is negligible, but it should be enough to determine the direction of spin. The F = vXB term in the Lorentz force is in fact the Coriolis force. You need to open your mind to the fact that space is dynamic and permeated with tiny vortices that align solenoidally and form magnetic fields. Kepler's law of areal velocity is the link between gravity and magnetism. The space vortices are all on the small scale. David Tombe 14th April 2007 (61.7.158.134 12:58, 14 April 2007 (UTC))

There is a much simpler mechanism to explain how the Coriolis force is related to the Earth's spin; it is friction between the atmosphere and the surface of the Earth. If you were to actually look at the atmosphere beyond the narrow mid-latitudes view, you'd see that it is not entrained in lock-step with the planet's rotation; indeed, this is why weather systems are not stationary. Due to Coriolis effects, the atmosphere actually travels in a number of bands around the planet, alternating direction relative to the planet's rotation. This is why mid-latitude weather systems such as those that affect me in Michigan or people in the United Kingdom travel in a generally west-to-east direction, while tropical systems like hurricanes travel in a generally east-to-west direction. Indeed, the southern part of the continental United States lies pretty much on a boundary area between two of these zones of opposing atmospheric movement, thus explaining why hurricanes approaching the US gradually change heading in a counterclockwise direction as they near the latitude of the Gulf Coast and eventually travel back out into the Atlantic.

As for the "similarity" between tropical cyclones and tornadoes, there is virtually no similarity if you look more closely at them. A tropical cyclone such as a hurricane is, at the most basic level, a simple surface-level low-pressure system, albeit a very deep one; it is a mesoscale phenomenon. The tornado is a small phenomenon related to an individual thunderstorm cell; it is a microscale phenomenon. Trying to compare hurricanes and tornadoes is a real apples and oranges comparison, because they're completely different sorts of systems.

Tropical cyclones are more accurately compared to the winter storms of the Great Lakes and the North Atlantic, which, like all low-pressure systems, invariably show cyclonic rotation due to Coriolis effects. Tornadoes, in terms of scale and behavior, are much more similar to your example of water draining from a bathtub than they are to tropical cyclones. Rdfox 76 13:25, 14 April 2007 (UTC)

If the Earth's atmosphere was lagging the Earth's rotation even to the slightest degree, can you think of any reason why this should be so? I can't. What would be holding the atmosphere back? The moving bands that you are talking about are the consequence of the Coriolis force. They are not the lagging effect which would be necessary to cause the fictitious Coriolis effect that you have in mind. The Coriolis effect on the atmosphere has been caused by something else much more real than that which causes the Foucault pendulum to precess.

You say that cyclones and tornadoes are as different as apples and oranges. But for the purposes of this discussion they are both atmosphereic vortices and they both have their spin direction determined by the direction of the Earth's spin, and in both cases, the cause must be non-fictitious because the vortices can be observed from outside of the Earth's rotating frame of reference. David Tombe 14th April 2007 (61.7.159.15 16:01, 14 April 2007 (UTC))

All right, I'm giving up on this. You seem to fail to recognize the difference between mesoscale and microscale phenomena; the fundamental difference between mesoscale and microscale meteorological systems; and the simple fact that having the same results with or without a given term in an equation indicates that the term in question is insignificant. People have pointed you at the equations needed to prove the insignificance of Coriolis effects, be they the fictitious force or the "real" force you claim, in the formation of tornadoes, but you still refuse to recognize it. Personally, I don't feel like beating my head against the wall (or is it a horse cadaver?) any longer, so I'm dropping out. If someone else wants to take over, feel free. Rdfox 76 16:31, 14 April 2007 (UTC)

Here is the simplest wikipedia answer to this disagreement: meteorology texts are the consensus view within the topic of meteorology. They state that coriolis is negligible at the scale of a tornado (microscale). This means that it must be stated within the article that coriolis is negligibile since it is the consensus view. Any meteorological qualms you have with this view, according to wikipedia, are not to enter the article. In fact, from what I understand, personal beef with the consensus view shouldn't even enter the talk page. This is what has made the global warming article such a nightmare to contribute towards. Thegreatdr 20:01, 14 April 2007 (UTC)

Continuing research section

I've expanded the continuing research section with the big areas of study and a cursory mention of research methods. Cognizant of limiting the size of the main article, I've limited it for now. One could elaborate on the ways instruments are used (and different kinds of instruments) as well as research methodologies such as field programs, observational analysis, and numerical modeling, but the latter is probably extending beyond the scope of the section. The continuing research section was pegged for expanding, is it now suitable? Evolauxia 11:43, 11 April 2007 (UTC)