Surviving an EF5, Video from inside the Greensberg tornado

It's almost like another cell/flank to the west of the main updraught surges eastwards just after the storm passes through Greensburg. The area of interest is on the velocity loop Bill has posted above, and develops across/close to Bucklin, before surging east. In the period just before, it's almost as if the Greensburg cell begins to turn left as the area of interest to the west starts to move ESE. As the area of interest (I'm calling it that because I don't know whether it's another small circulation or just a surging gust front) passes close to Mullinville, it and the main Greensburg meso seem to try to rotate (briefly) about a common centre of gravity, which is centred just west of Greensburg. As the surge continues to move from the west, it seems to push the Greensburg meso off to the ENE, at which time, the new meso is already forming.

It's hard to write what I'm trying to explain, but have a good look at the radar loops, and see if you can spot the centre of gravity I think I can see.
 
EF5 Video

Disappointed that you're not going to post a link to the video of this event - it's pretty clear from all that you've said that you don't condone night time chasing, but the video, given the context you've set wouldn't glamorise that - I was looking forward to getting a real appreciation of what can go wrong suddenly in a chase - night or day - it's easy to get complacent about tornados after years of chasing - this is a salutary lesson on what can go wrong, even with the best of weather tools at hand.
 
Announcement,

We are still editing the video from the Greensberg tornado. After muc discussion with the team we ARE going to release the story and videos. The majority of the proceeds will be given back to the people of Greenberg. One idea is that we donate to the Greensberg Fire Department to help them get new equipment.

I will make an announcement when the MESO video will air.

Randy
 
Paul I saw the same thing...I'm still convinced that there was a mesolow west-northwest of Greensburg. Plus that serious RFD blast was probably very damaging as well. It was like 3 serious punches thrown at that town in a period of 10-15 minutes...and the rest places this huge F5 tornado up into the historical category. In fact this whole May 4th event falls into that category given the massive sizes of the tornadoes and the multiple giant wedges on the ground at the same time. That was beyond impressive. I plan to e.mail Tom Grazulis and see if he knows of any such event as this one that was violent and cyclic.
 
Randy Zenzer said:
Ok,

Can you give me a percentage? How many tornadic cells out of 100 come to a stop and turn left?

I am very curious if there are any stats on this... Especially if it is common...
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It's relatively common, particularly for the significant (EF2+) tornadoes.

Most hook echoes develop on the right rear or rear flanks and are related to a rearward extension of echo and subsequent progressive southward and eastward curl of precipitation by the mesocyclone/tornado. At times the hook (or appendage) may be sustained but more often it will swing eastward and northward "wrapping‑up" and merging with the main echo body. This process is caused by the "occlusion" of the associated surface gust front wave, an augmentation of a nearby "rear flank" downdraft and the circulation modification from a convergent to non‑divergent or divergent mesocyclone core (Burgess et al., 1982; Lemon and Doswell, 1979; Brandes, 1984; Klemp, 1987; and others). This process is often followed by subsequent mesocyclone core development (at the occlusion triple point) forward and to the right of the previous core location. This new mesocyclone core formation will often result in repeated hook development, wrap‑up and tornado formation.

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A rare but significant variation of the above processes involves the persistence of the occluded (old) mesocyclone core. This mesocyclone may become associated with such large concentrations of vorticity and circulation that it will persist and grow in size during its leftward movement relative to storm into and through the high reflectivity storm core, sometimes exiting the echo mass on its left or rear flank. During this process the reflectivity core or cores may be swept into a "Fig. 6" curl, donut or swirl near the echo center, sometimes creating an entire "rotating echo." These persistent, leftward‑deviating circulations may then be revealed on the storm left or rear flanks by the emergence of a "backward" or "mirror image" cyclonic hook echo. Note...these are really cool to see!
 
This happened back in late April with the storms in Goodland, KS. The monster storm to the southeast of Goodland occluded and the occluded meso proceeded to exit the storm on the left flank and went on to become another cell which soon had a tornado warning. I have slept a lot since then, but I believe this cell went on to produce the tornado that was visible to the north of the Goodland NWS office (not sure about that though).

I had the data archived but due to a hard drive failure 2 weeks ago, it's lost. When I have time, I'll get it from NCDC again.
 
Bobby Prentice said:
A rare but significant variation of the above processes involves the persistence of the occluded (old) mesocyclone core. This mesocyclone may become associated with such large concentrations of vorticity and circulation that it will persist and grow in size during its leftward movement relative to storm into and through the high reflectivity storm core, sometimes exiting the echo mass on its left or rear flank. During this process the reflectivity core or cores may be swept into a "Fig. 6" curl, donut or swirl near the echo center, sometimes creating an entire "rotating echo." These persistent, leftward‑deviating circulations may then be revealed on the storm left or rear flanks by the emergence of a "backward" or "mirror image" cyclonic hook echo. Note...these are really cool to see!
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Whoa, that's incredible if true. I knew that torns can be wrapped up and inside the cell in the configuration of HP's, but didn't know that could translate through all the high reflectivity and actually emerge on the back side. As I understand, nowadays, core punching tornadic storm core's is now somewhat common place. For those chasers...think of the implication. Note: I know MESO didn't intend to do this. Storms are dynamic animals and sometimes they catch all of us with an occasional surprise.

On another note I was looking at the NWS site which is documenting the Greensburg tornado and they show the path actually crossing and going west of hwy 183 for a bit. The MESO team was indeed very fortunate if this is true.

Oh PS: It also shows another tornado forming ne of town that starts out 2+ miles wide!!! Darn I wish my Tahoe hadn't broken down on me.
 
I hate to say this,with the amount of life lost and damage done, but it seems very much like, the supercell that dropped the Greensburg Wedge, was nothing more, than an utter beast fest, due to the fact that it had dropped, what appears to be 3x monster wedge, 2x of which appear to have been a least 1.5 - 2 miles wide, but also the fact that the supercell, seemd to repeatedly have the meso, coil back in on itself, which is also kinda weird.

In circumstances like that, I'll be suprised if this particular scenario isn't still being studied to an extent over the next 2 - 3 years, because of how incredibly rare it is for this scenario to occur.

I'm looking forward to the pics and/or video Randy.

Willie
 
Willie Dines said:
In circumstances like that, I'll be suprised if this particular scenario isn't still being studied to an extent over the next 2 - 3 years, because of how incredibly rare it is for this scenario to occur.
Willie
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I'm not sure it's that rare. The mesocyclones hooked leftward as they began to contract and weaken, which is typical of the "textbook" mesocyclone occlussion, whereupon mesocyclonegenesis occurs to the east of the occlussion.

I did find it fascinating, however, that there were strong echoes that rotated from the northwest-west side of the storm to the southeast then east in an incredibly rapid manner. I assume these are associated with intense RFD surges, but I noted it occurring at least twice (and probably thrice) as the old meso turned left and before the new meso really intensified. When this assumed RFD surge met with the south side of the new meso, the meso intensified rapidly and grew in size, while the reflectivity associated with the RFD surge took on the "hammerhead" appearance (with an anticyclonic couplet on the south side of the RFD). Regardless, I don't think I've ever seen reflectivity protrusion move that quickly before, but perhaps I shouldn't be surprsied given the intensity and size of the mesos and RFDs.
 
That's what I was thinking of, not so much the cyclical supercell part.

The possibility of the meso(s) being intensified by possible RFD surges, is similar to having a tornado machine and then gently blowing into the tornado, on it's right side, as this naturally increases the intensity of the rotaion speed.

I was also suprised by the anticyclonic couplets, but I feel they may be a sign of short, but strong downdrafts, forcing some of the rotation to go the other way, as I have found that happen from time to time whilst using the tornado machine, where I would be getting great rotation, but there appeared to be a downdraft that was slightly stronger, than the updraft, in a way, that it still creates a tornado, but it is rotating anticyclonicly.

Does that make any sense?

Willie
 
I understand how the RFD surge can add to the circulation of the meso, and intensify it, but I am curious about the temperature of the RFD air, and how its entrainment into the meso might affect the strength of the updraft.

Might this have an effect, or is it just not considered to be significant?

Thanks,

John
 
John Hudson said:
I understand how the RFD surge can add to the circulation of the meso, and intensify it, but I am curious about the temperature of the RFD air, and how its entrainment into the meso might affect the strength of the updraft.

Might this have an effect, or is it just not considered to be significant?

Thanks,

John
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From what I've read, the RFD's caracteristics seem to be a significant factor not only in tornadoe genesis but also in tornado strenght.
 
Here is an image I captured from the video of the MTN. It shows our position, time and radar images. I will load more when I firgure out how.
 

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