HurricaneJosh

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.

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

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...

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.

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.

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.

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.

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.

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.

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.gov/images/dmx/parkersburg/Final-small-PDF-PARKERSBURG-NEW-HARTFORD-IOWA-EF-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).

If you're paraphrasing the report accurately, that's actually quite incredible, in that it seems to be suggesting a continuous swath of EF5 damage, which I've never even heard of. (Usually, even in the most extreme cases, the EF5 instances are isolated-- mere dots in the greater damage swath.) Re: Wichita Falls 1979... Yeah, the really impressive thing about that one has always been that the peak damage swath (F4) was wide and continuous. It mowed down a large area and remains one of the more spectacular non-F/EF5s in American history.

Wow-- thanks for creating this side-by-side. Can you describe the structure for us? Like was it solid brick? Was it steel-reinforced? How big? How many stories? Etc.

It is the highest official toll in a single American tornado since 1947.

Ugh! This and the mistaken gas-station receipt in IN are almost disappointing, in a weird way. The Joplin catastrophe is so enormous, it's like we want special confirmation of it in these novelties. Is this one a deliberate hoax? The receipt was an honest mistake, and the folks who discovered it immediately came clean when they realized.

Why is Moore so clearly stronger, in your opinion? And why Jarrell? I've actually heard some skepticism Re: that one-- doubts about the quality of the construction, etc.

You're from Joplin, too?? So what did you experience? Please share!

Wow-- just fascinating. I was wondering how soon after your post the tornado struck. I figured it was a couple of minutes. I have to say, your last few posts kind of haunted me for a couple of days-- specifically, the red ones.

Nothing to be sorry about. It's a good place to learn. (I'm no expert on tornadoes, either.)

I believe tornadoes are rated by the highest estimated 3-second value. I know for sure it is not a 1-minute sustained wind. Definitely not. The estimate says the max winds may have reached 250 mph. No one should be extrapolating higher "gust" values from that. They mean the 250 as the peak.

Winds up to 250 mph? Is that a finding from the official survey? If so, holy sh*t. This thing was literally off the charts. Since the Fujita scale was revised/enhanced and the wind values were made more reality-based, I never again expected to see a credible source suggesting wind speeds that high in a tornado. That is just nuts. The human tragedy aside, I am in complete awe of this event-- not only the intensity, but the speed of its development and the very short lifespan (for a tornado of this intensity). The whole thing is simply bizarre-- like a bomb went off.

Totally agreed. I'm sorry, but they just have no credibility. There always seems to be an ulterior motive in every utterance, every forecast map, every seemingly analytical remark, every historical comment, every graphic.

Ugh-- so tacky.

Omg. Wow. Scary sh*t. What's especially interesting is how it's practically at the surface-- suggesting those max winds were really gouging down to the ground with this thing.

Another very interesting detail.

Back to the meteorological aspects: notice that JoMo describes that same lull that we heard in the now-famous convenience-store video and that we saw in that video of someone's back lawn (with the trampoline). Interesting.