Devastating tornado strikes Joplin, Missouri

[HurricaneJosh]

Easy to see where the continuous 5 damage is and where the actual track was in relation to the warnings discussed

Not to disagree here, but I don't think it's possible to make a determination of continuous EF5 damage from a casual glance at a single aerial shot. If it were that easy, they wouldn't need to send in the dudes to do the ground surveys. Also, like I mentioned above, EF5 damage is usually determined to have occurred in spot instances-- not a continuous swath.

What we definitely do see is a continuous swath of very heavy (EF3+) damage.

[ORH_wxman]

Not to disagree here, but I don't think it's possible to make a determination of continuous EF5 damage from a casual glance at a single aerial shot. If it were that simple, they wouldn't need to send in the dudes to do the ground surveys. Also, like I mentioned above, EF5 damage is usually determined to have occurred in spot instances-- not a continuous swath.

What we definitely do see is a continuous swath of very heavey (EF3+ damage).

Right they have to check the building construction too. That's what led to the controversy over the Worcester tornado in 1953 (I started a thread on it in the NE subforum). If the building codes are in question, then what looks like F5 damage might not necessarily be. Healthy trees being snapped off fairly relatively low on the trunk tends to be a good indicator too.

[HurricaneJosh]

Right they have to check the building construction too. That's what led to the controversy over the Worcester tornado in 1953 (I started a thread on it in the NE subforum). If the building codes are in question, then what looks like F5 damage might not necessarily be. Healthy trees being snapped off fairly relatively low on the trunk tends to be a good indicator too.

Yep.

Personally, whenever I see a shot of a neighborhood mowed down, my assumption is always F4/EF4 unless the engineers on the ground specifically cite instances of EF5 damage. In this case (Joplin), the survey team determined at least four EF5 instances, whereas in Tuscaloosa, they didn't find any. It just goes to show that we can't tell just looking at a few photos.

The popular litmus test-- "Was the house swept off its foundation?"-- isn't even sufficient evidence in itself, as we saw in La Plata, MD.

Back to Joplin... I really do hope they do some very detailed plotting of the damage-- so we can see just how extreme this event was.

[thewxmann]

Yep.

Personally, whenever I see a shot of a neighborhood mowed down, my assumption is always F4/EF4 unless the engineers on the ground specifically cite instances of EF5 damage. In this case (Joplin), the survey team determined at least four EF5 instances, whereas in Tuscaloosa, they didn't find any. It just goes to show that we can't tell just looking at a few photos.

The popular litmus test-- "Was the house swept off its foundation?"-- isn't even sufficient evidence in itself, as we saw in La Plata, MD.

Back to Joplin... I really do hope they do some very detailed plotting of the damage-- so we can see just how extreme this event was.

From what I've heard, construction standards in the Southeastern U.S. are much weaker than construction standards in the Midwest/Heartland... I think that may have made the difference here.

[sojitodd]

Yep-- I looked it up after that discussion last night. It's d*mn impressive to see that many EF5 instances, but this in itself does not suggest that the EF5 damage was continuous between these points. That would be astonishing. (But then again, nothing surprises me about this one anymore.)

I hope they do a really detailed damage-swath map-- like this gorgeous one they did for Parkersburg-New Hartford: http://www.crh.noaa....F-5-TORNADO.pdf (Notice on this one how the EF5 instances are just dots in a swath of EF4 damage.)

I also hope in the final survey they settle on a specific max value for the winds-- rather than just "in excess of 200 mph". I'd like to know how this compares with Greensburg and Parkersburg-New Hartford (both of which were estimated at 205 mph).

Well back on post 467 is where they discuss the 'upgrading' and that is where those 225-250mph winds were mentioned. If they mentioned that(someone from the NWS) then you would think they would incorporate that into the max wind value-why mention it otherwise? But who knows. We have had 198mph, then 'in excess of 200 mph, and then the mention of the 225-250 mph in the article right at that time. From what it said, the 'in excess of 200 mph' was also still another 'preliminary'..so who knows?

If they really think 225 to 250 is correct as stated , then I hope it is listed officially as along that.

[HurricaneJosh]

Well back on post 467 is where they discuss the 'upgrading' and that is where those 225-250mph winds were mentioned. If they mentioned that(someone from the NWS) then you would think they would incorporate that into the max wind value-why mention it otherwise? But who knows. We have had 198mph, then 'in excess of 200 mph, and then the mention of the 225-250 mph in the article right at that time. From what it said, the 'in excess of 200 mph' was also still another 'preliminary'..so who knows?

If they really think 225 to 250 is correct as stated , then I hope it is listed officially as along that.

I was wondering about those values (225 and 250 mph). Two things:

1) I heard that those were "instantaneous" speeds, whereas a tornado is rated as per the highest estimated 3-sec value-- so I wonder if perhaps those peak values wouldn't count as the official value (sort of how a hurricane is referred to by its max 1-min wind, not peak gust).

2) I am having a hard time imagining that the official max estimated wind speed for this tornado would be a whopping 12-25% higher than the Greensburg and Parkersburg values (205 mph). That would be almost inconceivable. But then again, maybe it really was that unique of an event.

[CoastalWx]

Yep.

Personally, whenever I see a shot of a neighborhood mowed down, my assumption is always F4/EF4 unless the engineers on the ground specifically cite instances of EF5 damage. In this case (Joplin), the survey team determined at least four EF5 instances, whereas in Tuscaloosa, they didn't find any. It just goes to show that we can't tell just looking at a few photos.

The popular litmus test-- "Was the house swept off its foundation?"-- isn't even sufficient evidence in itself, as we saw in La Plata, MD.

Back to Joplin... I really do hope they do some very detailed plotting of the damage-- so we can see just how extreme this event was.

Interesting you brought that up. I was just talking to someone about that tornado and they mentioned the controversy of that tornado.

[gymengineer]

Check back at the survey map page-- the Springfield office has attempted a preliminary damage contour map. It's hard for me to see on my computer screen if there is an additional darker shade inside the EF4 swath.... it looks that way, but the "darker" shade is almost indistinguishable to my eyes. Can the rest of you see it more clearly?

ETA: The "5" markers are still there in the same locations.

[sojitodd]

Check back at the survey map page-- the Springfield office has attempted a preliminary damage contour map. It's hard for me to see on my computer screen if there is an additional darker shade inside the EF4 swath.... it looks that way, but the "darker" shade is almost indistinguishable to my eyes. Can the rest of you see it more clearly?

ETA: The "5" markers are still there in the same locations.

If you zoom in, it definetely looks like a 2-3 block line of ef5 from about the hospital to just short of Duquesne-nearly 4 miles. They have a darker color that goes the length-where they ef5 markers are-and it is a different swath than the areas given the ef4 and ef3-if you zoom in it is continous and about 2-3 blocks wide.

the ef5 and ef4 damage swath is much wider than even the Wichita Falls tornado-- nealy 1/4 mile wide for over 4 continous miles.

*the ef4 seems to start just before Shifferdecker...and the ef5 seems to start just after S. Maiden lane, right above the H for the hospital-it looks to be about 3 blocks wide around the Missouri/Ohio ave areas.

[HurricaneJosh]

Check back at the survey map page-- the Springfield office has attempted a preliminary damage contour map. It's hard for me to see on my computer screen if there is an additional darker shade inside the EF4 swath.... it looks that way, but the "darker" shade is almost indistinguishable to my eyes. Can the rest of you see it more clearly?

ETA: The "5" markers are still there in the same locations.

If you zoom in, it definetely looks like a 2-3 block line of ef5 from about the hospital to just short of Duquesne-nearly 4 miles. They have a darker color that goes the length-where they ef5 markers are-and it is a different swath than the areas given the ef4 and ef3-if you zoom in it is continous and about 2-3 blocks wide.

the ef5 and ef4 damage swath is much wider than even the Wichita Falls tornado-- nealy 1/4 mile wide for over 4 continous miles.

*the ef4 seems to start just before Shifferdecker...and the ef5 seems to start just after S. Maiden lane, right above the H for the hospital-it looks to be about 3 blocks wide around the Missouri/Ohio ave areas.

I see the slightly darker "inner" isotach as well-- but the problem is that the colors on the map don't match the colors on the legend, so it's hard to know what values these shades map to.

Even with this tornado, I would be skeptical Re: the idea of a continuous, unbroken swath of EF5 damage going for several miles like that.

[sojitodd]

I see the slightly darker "inner" isotach as well-- but the problem is that the colors on the map don't match the colors on the legend, so it's hard to know what values these shades map to.

Even with this tornado, I would be skeptical Re: the idea of a continuous, unbroken swath of EF5 damage going for several miles like that.

The colors do match when you zoom in and out-they change-and that is certainly a separate swath and is defined from the other areas by the ef markings. If you zoom in it is unmistakable. That is what us on the map. There are five distinct swaths to match the five choices on the legend( there is no ef0 on the legend).

I am not saying this is what is true in reality, but that is what is on the map-no question about it.

*typing/keying bad because of sliced right hand from working in yard yesterday with no gloves

*it does say they are estimates and may not be accurate down to the 'sub neighborhood level' -so it does have some kind of disclaimer.

[HurricaneJosh]

The colors do match when you zoom in and out-they change-and that is certainly a separate swath and is defined from the other areas by the ef markings. If you zoom in it is unmistakable. That is what us on the map. There are five distinct swaths to match the five choices on the legend( there is no ef0 on the legend).

I am not saying this is what is true in reality, but that is what is on the map-no question about it.

*typing/keying bad because of sliced right hand from working in yard yesterday with no gloves

*it does say they are estimates and may not be accurate down to the 'sub neighborhood level' -so it does have some kind of disclaimer.

Weird. On my computer the colors don't match, even when I zoom in real close. EF5 in the legend is a heavy, brick red, and there is no such color on the map.

Also, look at the size of that area-- it is huge. There would need to be solid EF5 damage to over 50 or maybe even 100 homes to justify that isotach if it means EF5.

[sojitodd]

Weird. On my computer the colors don't match, even when I zoom in real close. EF5 in the legend is a heavy, brick red, and there is no such color on the map.

Also, look at the size of that area-- it is huge. There would need to be solid EF5 damage to over 50 or maybe even 100 homes to justify that isotach if it means EF5.

The colors match for me briefly as i zoom in and out-and then go back .

There are five distinct zones/swaths and there are five choices on the legend. The swaths themselves are marked as well with the appropriate ef marker.

I am not saying the map is 'right' or 'accurate', but what I am stating is what the map shows. I can't say if it is correct or not, but I can clearly see what that map shows, and it does show a continous swath of ef5 damage from 2-3 blocks wide for nearly 3.5 miles.

Whether this is the case or not, I don't know-but that is clearly what that map shows imo.

I think it is important to note that there are clearly five swaths, and only five identifiers on the legend-ef1 -ef5. How else could you explain it, unless they made a big mistake on the map?

*there is no ef0 on the legend, but at the far end of the track, they have the symbol/marker for ef0, but it is in the same color swath as the ef1 marker is....???? I wonder if maybe there was a mistake? They do not have the ef0 on the legend as far as I can see? hmmm....

[HurricaneJosh]

The colors match for me briefly as i zoom in and out-and then go back .

There are five distinct zones/swaths and there are five choices on the legend. The swaths themselves are marked as well with the appropriate ef marker.

I am not saying the map is 'right' or 'accurate', but what I am stating is what the map shows. I can't say if it is correct or not, but I can clearly see what that map shows, and it does show a continous swath of ef5 damage from 2-3 blocks wide for nearly 3.5 miles.

Whether this is the case or not, I don't know-but that is clearly what that map shows imo.

I think it is important to note that there are clearly five swaths, and only five identifiers on the legend-ef1 -ef5. How else could you explain it, unless they made a big mistake on the map?

I understand why you reach that conclusion-- because it's logical, given that there are 5 colors in the legend and 5 colors on the map. I'm wondering if maybe that inner isotach equals high-end EF4 vs. lower-end EF4-- like a half-grade indicator. I know that might sound ridiculous, but I find it almost impossible to buy the idea of an EF5 damage area being that large, when for every other F5/EF5 historically, the instances were just a house or two or maybe a handful of homes at one end of a subdivision.

[sojitodd]

I understand why you reach that conclusion-- because it's logical, given that there are 5 colors in the legend and 5 colors on the map. I'm wondering if maybe that inner isotach equals high-end EF4 vs. lower-end EF4-- like a half-grade indicator. I know that might sound ridiculous, but I find it almost impossible to buy the idea of an EF5 damage area being that large, when for every other F5/EF5 historically, the instances were just a house or two or maybe a handful of homes at one end of a subdivision.

I am wondering now too, given that they have the efo and ef1 markers in the far right of the path in the same swath, but there is no ef0 marker/color on the legend. I am now not as sure-maybe a mistake was made. It still appears that they have a continous swath of ef5 damage, but it may not be accurate. That and the colors not matching up, and the same color apparently being used for ef0(not on the legend but on the map) and ef1(on the legend and on the map).

[HurricaneJosh]

As an example of what I'm talking about... This is is from the preliminary survey of the Moore, OK, tornado. Even with that one, it was only a small handful of homes that received F5 damage:

THE WORST DAMAGE SEEN ALONG THIS ENTIRE PART OF THE PATH WAS IN THE EASTLAKE ESTATES... NORTH OF 134TH AND BETWEEN PENN AND WESTERN. ENTIRE ROWS OF HOMES WERE VIRTUALLY FLATTENED TO PILES OF RUBBLE. FOUR ADJACENT HOMES ON ONE STREET WERE VIRTUALLY CLEANED OFF OF THEIR FOUNDATIONS... LEAVING ONLY CONCRETE SLABS. THESE HOMES EARNED THE F5 RATING...

[HurricaneJosh]

I see tornadotony lurking. I'd like to hear his opinion-- he's an expert on this topic. Tony?

[winterymix]

I just took another look at the Springfield WSO site. They have the obvious link to the survey for the tornado. If one looks off to the side,

there is a menu item to "view a larger map". If one opens that up and further enlarges the image, it becomes quite obvious that the

authors wanted to depict a large and significant continuous zone of F-5 forces.

This is a rare and extreme catastrophe in the center of a small to mid-side city.

Josh, if you look at the side menu for google maps, you will note that kilometers 4 through 7 all

experienced winds > 200 moh.

I know you want more exact wind speeds but it is up to the WSO to release that info.

[HurricaneJosh]

I just took another look at the Springfield WSO site. They have the obvious link to the survey for the tornado. If one looks off to the side,

there is a menu item to "view a larger map". If one opens that up and further enlarges the image, it becomes quite obvious that the

authors wanted to depict a large and significant continuous zone of F-5 forces.

This is a rare and extreme catastrophe in the center of a small to mid-side city.

I wouldn't say it's obvious, due to the confusion Re: the colors. (See our discussion above.)

Also, I strongly doubt that that is what occurred on the ground. It might have been the strongest tornado in the history of the USA. Even so, I don't buy solid EF5 damage over that large an area.

[sojitodd]

As an example of what I'm talking about... This is is from the preliminary survey of the Moore, OK, tornado. Even with that one, it was only a small handful of homes that received F5 damage:

THE WORST DAMAGE SEEN ALONG THIS ENTIRE PART OF THE PATH WAS IN THE EASTLAKE ESTATES... NORTH OF 134TH AND BETWEEN PENN AND WESTERN. ENTIRE ROWS OF HOMES WERE VIRTUALLY FLATTENED TO PILES OF RUBBLE. FOUR ADJACENT HOMES ON ONE STREET WERE VIRTUALLY CLEANED OFF OF THEIR FOUNDATIONS... LEAVING ONLY CONCRETE SLABS. THESE HOMES EARNED THE F5 RATING...

Actually I think I saw a study of this tornado where there were more than five homes getting f5 ratings in that subdivision, and some of them were not adjacent..

..anyway I just hate it when maps have ambiguities..(I was a Urban and Economic Geography major in college)..it just pisses me off to no end.

*I do get what you are saying though Josh...I was shocked to see that swath of ef5 and it does seem to be almost incredible. Not what I expected at all. I expected the 'spotty' thing as well, hot a solid 2-3 block swath(isotach) for 3.5 plus miles.

[winterymix]

I wouldn't say it's obvious, due to the confusion Re: the colors. (See our discussion above.)

Also, I strongly doubt that that is what occurred on the ground. It might have been the strongest tornado in the history of the USA. Even so, I don't buy solid EF5 damage over that large an area.

Kindly take a look at that left-side menu in google maps.

[HurricaneJosh]

Actually I think I saw a study of this tornado where there were more than five homes getting f5 ratings in that subdivision, and some of them were not adjacent..

Correct, there were other instances of F5 damage in that storm. My point is simply that when there are instances, they're highly localized.

The Parkersburg-New Hartford tornado produced EF5 damage in two towns very far apart-- but the instances were isolated.

..anyway I just hate it when maps have ambiguities..(I was a Urban and Economic Geography major in college)..it just pisses me off to no end.

Ugh-- me, too!

[tornadotony]

I understand why you reach that conclusion-- because it's logical, given that there are 5 colors in the legend and 5 colors on the map. I'm wondering if maybe that inner isotach equals high-end EF4 vs. lower-end EF4-- like a half-grade indicator. I know that might sound ridiculous, but I find it almost impossible to buy the idea of an EF5 damage area being that large, when for every other F5/EF5 historically, the instances were just a house or two or maybe a handful of homes at one end of a subdivision.

No, it's definitely the EF5 indicator. The colors get a bit garbled on the map because of how they overlay.

[HurricaneJosh]

Kindly take a look at that left-side menu in google maps.

OK, cool. I looked at it and I see what you're saying. When you check and uncheck the EF5 checkbox, that inner isotach appears and disappears. So, we now know they did, in fact, mean EF5. That mystery is solved.

It doesn't change my skepticism a bit. I can only assume that map is meant as an extremely rough approximation.

[HurricaneJosh]

No, it's definitely the EF5 indicator. The colors get a bit garbled on the map because of how they overlay.

Yeah, see above. winterymix pointed out the menu on the left, where you can check and uncheck the isotachs to make them appear and disappear.

But, you're an expert in this stuff. Do you believe the EF5 damage area is that large and solid?

[sojitodd]

OK, cool. I looked at it and I see what you're saying. When you check and uncheck the EF5 checkbox, that inner isotach appears and disappears. So, we now know they did, in fact, mean EF5. That mystery is solved.

It doesn't change my skepticism a bit. I can only assume that map is meant as an extremely rough approximation.

I agree with your skepticism, but it still makes for one hell of a mesmerizing and incredible map!

[HurricaneJosh]

I agree with your skepticism, but it still makes for one hell of a mesmerizing and incredible map!

Yep.

Tony's about to post-- curious what his opinion is.

[HurricaneJosh]

Everyone--

Check out this map: http://maps.google.com/maps?f=q&source=embed&hl=en&geocode=&q=http:%2F%2Fwww.crh.noaa.gov%2Fimages%2Fsgf%2Fevents%2F2011may22%2FJoplin_damage_path_all.kmz&aq=&sll=37.05253,-94.475199&sspn=0.20276,0.299034&ie=UTF8&ll=37.057369,-94.478302&spn=0.131512,0.219727&t=p&z=12

Uncheck all of the boxes except F5. Then zoom in real close and look at how many houses and buildings this presumed EF5 area encompasses.

[tornadotony]

I see tornadotony lurking. I'd like to hear his opinion-- he's an expert on this topic. Tony?

I doubt the entire area that SGF has painted as EF5 received EF5 damage. It's impossible to say. I didn't think we'd ever have a tornado on the EF-scale where the MIC at the office in whose CWA it hit would estimate a peak wind of 250 MPH. Think about what kind of damage would have to be done for that estimate and think about the EF-scale. Each ranking of the EF-scale goes by roughly 25-35 MPH gradations.

EF0: 65-85 MPH

EF1: 86-110 MPH

EF2: 111-135 MPH

EF3: 136-165 MPH

EF4: 166-200 MPH

EF5: >200 MPH

Essentially, if we still had a "6" rating for a tornado, following that pattern (and even incorporating the fact that the ranges increase as you go up), you'd likely expect this tornado to breach the minimum wind speed for that. Now, how you would describe something as a "6" would be beyond my paygrade. But I'm hoping this puts the level of damage that is being described from SGF into a proper historical perspective. When you legitimately estimate the max winds to be 50 MPH into EF5, you're essentially trying to describe this as being the strongest tornado at least ever surveyed.

[HurricaneJosh]

I see JoMo lurking. JoMo, were you in one of the colored areas? If so, which one?