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An F6 Tornado?

:?: I have read many textbooks on the matter of whether or not their has ever been an F6 tornado. The last time I checked Howard Bluestein had captured the fastest wind on record F5 speed for sure but is this information still up to date? A BBC textbook on understanding weather states that during the May 3rd 1999 outbreak in central Oklahoma their was an F6 tornado in that outbreak where as I have heard Meteorologists state that thier has never been an F6 tornado. In theory an F6 should still be possible I mean we just need to record a minimum windspeed of 319 mph for a tornado to officially be classified as an F6. So why is it that the tiny plastic portable tornado toy has it's Fujita scale stop at F5 with 261-318 mph? and some weather books don't even have F6 listed in the Fujita scale where as others do! Can anyone help with this??? I would think they should leave F6 in the scale as Dr Fujita intended, it is his scale after all and we have had tornados that are just a few miles below F6 standards. An F6 has to happen sooner or later and the chaser that bags it will get the publicity of a lifetime.
 
Am I correct that the scale actually goes up to F-12.. which would be wind speeds of Mach 1? I think they just stop at F5, because there hasnt ever been an F6, and the odds of one are so low. The winds in the May 3rd 1999 tornado were measured at 318 mph, not 319... and were measured some distance up in the tornado, thus the actual surface wind speeds were somewhat lower than that, still making it a strong F5, but still not that elusive F6.

EDIT: http://www.ncdc.noaa.gov/oa/satellite/sate...nal/fujita.html

I thought so.. the scale does indeed go From F0- F12.. however F6-12 are often left off due to the odds we'll never see one. For what it's worth though, an F12 would indeed have winds at Mach 1.. of 738 mph.. wouldnt that be something?
 
Ugh, I hate to reference TWC's Storm Stories for this, but that one May 3rd 1999 one is played so much. At the end, Jim Cantore deals with the F6 issue, becuase the windspeed was supposedly the strongest tornado on record. I don't exactly remember what his respones was... :?
 
Here's the problem.......

The Fujuta damage scale is based on exactly just that..... DAMAGE. The wind speeds given for each level of strength are only ESTIMATES of what it would take to possibly cause a certain kind of damage. Even if somehow, meteorologists were able to prove a 319 or high mph wind was in contact with the ground during a tornado, it would more than likely still be rated an F5 because what F6 damage there may be would be pretty much indistinguishable from the F4 and F5 damage surrounding it.....also remember that in some of the higher-end F5 tornadoes of the past, even housing foundations have been dislodged and swept away (Guin, AL 1974 for example), so as you go higher up in the F5 range....there may not be anything left to look for F6-like damage anyway.
 
Ah ha so we are only 1 mph off, that means we're getting closer to an F6. I have never seen the F scale go all the way to 12 wow Is this true? If so forget about an F6 I think I'll start looking for an F12 :shock: (you've just got to shoot for high goals no matter how unrealistic they really are)
 
If I remember right, F6 to F12, was to classify damage produced in the winds from a nuclear blast. BOOM! Those wind speeds can easily break 800 mph I believe
 
Originally posted by David Brookshier
Ah ha so we are only 1 mph off, that means we're getting closer to an F6. I have never seen the F scale go all the way to 12 wow Is this true? If so forget about an F6 I think I'll start looking for an F12 :shock: (you've just got to shoot for high goals no matter how unrealistic they really are)

Well, still.. as Fred stated.. how are we going to identify F12 damage. If an F5, or even F6 wipes everything clean.. what more can be done?
 
So, an F5 could potentially go through pure open country lands, and not event be given a higher F-Rating that F0-F1? I think that is absolutely crazy. This system for damage inspection is very imperfect, it needs to be changes, somehow. Can't they record wind speeds, VIA DOW and/or some sort of probing device/velocity scanning.


I am also wondering why an F5 tornado can go up to JUST 318, and that 1 small mile per hour, it needs to make F6 status is not attainable...how can this be? What would stop it from gaining an extra 1 MPH?


There might have been an F6, or even higher....before the Fujita scale was invented, or before his started being recorded.
 
Exactly... An F6 will NEVER occur - even if they record winds well in excess of 318MPH, it's still an F5. Why? Because the Fujita scale is purely a damage scale... You can only destroy something so much until there is nothing left to destroy (an F5 would do that).

Quite possibly though, if a tornado with a measured wind speed of 400MPH (obviously hypothetical) creates a unique ground swirl (or even "digs" into the SFC itself), then that would be the distinguishable factor and a higher rating might be warranted...
 
Personally, I think of F5 as "261 mph and up" rather than "261-318". It's the same with the Saffir-Simpson Hurricane Scale. 155 mph and up is a category 5-there's nothing higher. A 250 mph hurricane (!) would still be a category 5. A 400-mph tornado (also !) would still be an F5.
 
Originally posted by Andrew Khan
So, an F5 could potentially go through pure open country lands, and not event be given a higher F-Rating that F0-F1? I think that is absolutely crazy. This system for damage inspection is very imperfect, it needs to be changes, somehow. Can't they record wind speeds, VIA DOW and/or some sort of probing device/velocity scanning.
This happens very often. If a tornado doesnt hit anything, there is nothing to base it's intensity off of. Its a DAMAGE intensity scale, not a WINDSPEED scale..


I am also wondering why an F5 tornado can go up to JUST 318, and that 1 small mile per hour, it needs to make F6 status is not attainable...how can this be? What would stop it from gaining an extra 1 MPH?

If I remember right, the estimated wind speeds of a tornado have only exceeded 300 mph once, that being the May 3 1999 tornado. They arent saying a tornado can have a wind speed of 318, not 319.. but the odds of it even hitting the top of the F5 plateau are so tiny that the chances of going beyond it are almost nil.
 
I've watched a documentary on the Jarrell, Texas F-5 that featured Meteorologist Lon Curtis who chased this particular storm and they said their were cattle that literally had the lungs sucked right out of them! :shock: I also went through the damage path two days after the Lake Whitney tornado of 1999(or 2000). It was rated an F-3 and it destroyed everything in it's path, but we're not talking brick buildings here. Still, the damage was very impressive. I can't believe the damage an F-5 could produce, much less an F-6!
 
Originally posted by Chris Lott
I've watched a documentary on the Jarrell, Texas F-5 that featured Meteorologist Lon Curtis who chased this particular storm and they said their were cattle that literally had the lungs sucked right out of them! :shock: I also went through the damage path two days after the Lake Whitney tornado of 1999(or 2000). It was rated an F-3 and it destroyed everything in it's path, but we're not talking brick buildings here. Still, the damage was very impressive. I can't believe the damage an F-5 could produce, much less an F-6!
Yeah, I don't get it when people say the Jarrell tornado only produced F-5 damage because it was moving so slowly. Cattle being skinned and their lungs sucked out, vehicles thrown long distances, and people being mutilated and dismembered are examples of incredible phenomena, IMO.
 
Originally posted by Michael Aukerquote
Yeah, I don't get it when people say the Jarrell tornado only produced F-5 damage because it was moving so slowly. Cattle being skinned and their lungs sucked out, vehicles thrown long distances, and people being mutilated and dismembered are examples of incredible phenomena, IMO.


Put a blender on a lower setting and leave it on for awhile, you'll eventually get the same results as putting it on high for a short period.

Rob
 
Every scientific study that correlates wind speeds to F-scale shows that the speeds are too high... I.E. F5 could come with winds that are not as strong as listed, Dr F did not use any real research when he came up with the splits.

- Rob
 
Originally posted by rdale
Every scientific study that correlates wind speeds to F-scale shows that the speeds are too high... I.E. F5 could come with winds that are not as strong as listed, Dr F did not use any real research when he came up with the splits.

- Rob

I wonder what the actual numbers are closer to... Any research, or ideas?
 
Cattle were Skinned, and there lungs were sucks out.....? It seems very odd, and unlikely for cows to actually have there lungs and skin ripped off...but anything is possible, that's sad, however. I thought in order for your flesh to be ripped of winds would need to exceed 500 mph....
 
There could be an F-6 tornado. On the rare occasions when tornadoes have struck downtown areas (Lubbock, Topeka, Ft. Worth, etc.) most engineered buildings have little (in relative terms) damage. If a skyscraper was knocked down or an engineered building completely blown away it would be F-6 or higher.
 
If they look at rating tornados based on damage then they should seriously consider doing away with the exact wind speed classification system for example 261-318=F5 now curious people like myself will only end up asking ...so what happens at 319 if it's only damage they are looking for in rating tornados why use the current precise wind ratings for the respective F scale at all? Who knows maybe this is why many of the textbooks I've seen have done away with F6 but on the other hand shouldn't they also extend F5 tornado speeds beyond 318 to avoid confusion:?:
 
Originally posted by David Brookshier
If they look at rating tornados based on damage then they should seriously consider doing away with the exact wind speed classification system for example 261-318=F5 now curious people like myself will only end up asking ...so what happens at 319 if it's only damage they are looking for in rating tornados why use the current precise wind ratings for the respective F scale at all? Who knows maybe this is why many of the textbooks I've seen have done away with F6 but on the other hand shouldn't they also extend F5 tornado speeds beyond 318 to avoid confusion:?:

Basically, the wind speeds are complete crap. Every bit of damage done by a tornado is within a certain category on the scale.. The windspeeds generally are just a push for real wind speeds, as well as a way to seperate lower-middle-higher ends in the categories. But the rating is certainly determined by the damage caused.. and is usually explained in the NWS's surveys which are usually posted online after the tornado.
 
The Fujita Scale was designed as a wind speed scale but it is generally utilized as a damage scale. Fujita himself recognized that modern housing faltered at lower windspeeds. Tim Marshall has also shown this in numerous conference and professional papers. It is probably best to think of an F-rating in terms of damage rather than wind speed. As far as an F6 is concerned, the damage would not be easily distingished from an F5 as an F5 already cleans the plate. The only real way to distiguish an F6 from an F5 would be an actual wind measurement. Fujita stated an F6 is inconceivable but nobody said it was impossible. We only have about 50 years of video and 30 years of doppler data of a select few tornadoes within these time frames... But when you get right down to it, is there any real difference between 300 mph winds versus 320 mph winds?

fscale.jpg
 
"There could be an F-6 tornado."

No there cannot, at least with the F-Scale, because Dr F defined F5 as total cleansing...

"The only real way to distiguish an F6 from an F5 would be an actual wind measurement."

No, because the F-Scale is a damage scale.
 
Originally posted by rdale
\"There could be an F-6 tornado.\"

No, because the F-Scale is a damage scale.

Fujita imperically derived F-scale wind speeds by connecting the Beaufort scale to the Mach scale (see above chart), therefore, I will take the side that it was designed as a wind scale that in application only is a damage scale... I agree that for application purposes (rating damage), the highest rating will be F5.
 
Originally posted by APritchard+--><div class='quotetop'>QUOTE(APritchard)</div>
<!--QuoteBegin-David Brookshier
Ah ha so we are only 1 mph off, that means we're getting closer to an F6. I have never seen the F scale go all the way to 12 wow Is this true? If so forget about an F6 I think I'll start looking for an F12 :shock: (you've just got to shoot for high goals no matter how unrealistic they really are)

Well, still.. as Fred stated.. how are we going to identify F12 damage. If an F5, or even F6 wipes everything clean.. what more can be done?[/b]

I think I'd put one caveat here: while the Fujita scale is generally determined by damage, not wind guesstimates, it IS a scale directly linked to windspeeds. i.e., this windspeed causes this damage, therefore, this damage must correspond to this windspeed. If we had a very reliable way to directly measure windspeeds within the lower fifteen feet of a torndao, I would have no problem at all with using that data to determine where that tornado falls on the Fujita scale. We only use damage because that's the best we can do right now with current technology (i.e., most windmeters are destroyed by tornadoes and can't register speeds of 200+ anyway), and most of the time tornadoes don't pass overwindmeters. And doppler can't scan the very bottom of a tube.

Just as we look at damage and try to ascertain windspeed, I'd have no problem with directly measuring windspeed (if we could) and then correlating it with the kind of damage that could have occured, had the tornado hit something that could have registered that damage. Thus, if someone WERE able to directly measure a ground circulation of, say, 340mph, I'd be all for calling that an F6, even if that twister didn't hit Fort Knox to prove it.
 
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