Scud or Wall Cloud?

[John Hudson]

I was going through my video from the May 23 near Ness City, and was curious about something that appeared in the distance when we were filming the big supercell.

My first feeling was that it was scud, but after looking I thought it was maybe a wall cloud. We were on 283 I believe, about half way between Ness City and Ransom around 8:15 PM. The view is to the northwest.

http://www.youtube.com/watch?v=H-zUN8xmzws

Any thoughts/opinions?




John

 

[Jason Boggs]

My initial though was a large tornado, but I wasn't there so I can't speculate. It is indeed a large, well developed wall cloud that's scraping the ground, if it's not a tornado. It definitely looks attached, so it doesn't appear to be scud.

 

[John Hudson]

It is indeed a large, well developed wall cloud that's scraping the ground, if it's not a tornado. It definitely looks attached, so it doesn't appear to be scud.

I was thinking the same thing, that it appeared to be attached. Unfortunately, this appeared quite some time after my Telus card punched out, and I had absolutely no data.


John

 

[Bill Tabor]

Are you kidding? Definitely at least a wallcloud, but so low to the ground with possible ground interaction (tough to tell because of lighting) that it may actually be a tornado.

 

[Eric Sipes]

Definately a tornado. There is no question about it. It has a meso, rain in the RFD, a rainfoot, and large very dark core. I've enhanced an image below and then edited it to show all of the structure.

-Eric

Hit the magnifying glass at the bottom right of your screen to enlarge images.

 

[Bill Tabor]

Let me add that it visually appears to be a possible / or likely tornado but for verification we do really need visual confirmation of violent rotation and debris lifted or spun.

 

[mike scantlin]

no Bill, we don't. its definitely on the ground. Eric is right, with the structure, it's more than likely a tornado. if you feel that it was a tornado, thats all that matters. even if Bill wasn't there to tell you whether or not it was.

 

[John Hudson]

Thanks a lot for all your help, guys. I know it seems maybe a bit dimwitted that I was overlooking a lot of the details, but I've always tried to be fussy about what I called a tornado, and what I did not.

As I mentioned, I had absolutely no data to verify the rotation. And, the circumstances were a bit on the weird side. Was parked along the road with about five other chasers, and everyone else was just kind of mingling and chatting.

Was videotaping this "feature", trying to tell people around me "hey, doesn't that look a bit like a tornado?", but everyone was just kind of "Gee, I dunno....", or "Whatever, maybe..."

Strange days, indeed. Maybe there was just too many tornadoes and everyone was distracted.

I'll count it as a tornado


John

 

[Andrea Griffa]

One thing is sure: that is not a scud I wasn't there but to me too that's a probable tornado.

 

[Eric Sipes]

no Bill, we don't. its definitely on the ground. Eric is right, with the structure, it's more than likely a tornado. if you feel that it was a tornado, thats all that matters. even if Bill wasn't there to tell you whether or not it was.

Hmm, sarcasm, I like it.

Anyway, in the years I've spent watching storms, I've focused most of my efforts on learning storm stucture and how to pick out certain features. All the data in the world won't help you if you don't know what your looking at. I can still remember when I first started, I would always get side-tracked with rotation in the flanking line.

One way to always be sure is to look where the flanking line and beaver tail meet in the storm. That is the area of you main rotation. If you don't have these features, look for the features I named above. Given the "object" in your video seems to be rotating, if I was a spotter, I'd report it as a tornado.

-Eric

 

[Mike Peregrine]

I'm going to jump in as devil's advocate here ... if this is the same feature that I'm thinking of on the 23rd (which we saw as well), I think it may have been a decoy that is seen on the rear flanking line of strong supes at times. That was my thinking at the time, as it didn't appear to be rotating. I've seen these several times, usually associated with wet updrafts - and usually they are attached and can appear quite convincing. One example is a very similar feature that occurred on the Concordia, Kansas storm on 5/29/04. I noticed several chasers watching it intently on the 23rd, but it actually was not in the updraft/mesocyclone of the storm and had developed off the rear flank. The battle zone was north of Ness City at this point.

Now all of this is contingent on whether we are both referring to the same feature. I'll go back through my video, because I think I did snap a shot of it as I was explaining to my riders that day why I didn't feel that was what we needed to concentrate on at the time. Hope this helps -

 

[Mike Peregrine]

For some very similar examples, by the way - check out Roger Edwards' page here. About mid-way down you will see some photos by Mike Umscheid and others of non-rotating, low-hanging, attached clouds that look legitimate, but are actually decoys.

 

[scott r currens]

Hey John,

If I were you I go through all the chase reports and NWS damage surveys to see if anyone else has a tornado at that time and location. If you didn't think it was a tornado at the time what was you reasoning for that? Is that image alone enough to convince you that it is a tornado? Those are the kind of questions I ask my self when I have come accross images of suspicious features after the fact.

The following image is from EC NM of May 27, 2005. The wedge shaped condensation was in the "correct" portion of the updraft but had zero visible rotation.

 

[Jim Saueressig]

Looking ESE From just West of Welda Ks at area NE of Colony on Feb 28 2007 during that tornado. There appears to be a small tube (in the red box) coming down behind silo in the foreground. The silo was only a few miles away while the storm was many. Some have said the big wedge shaped area behind it was the wedge from that night but for me the only thing that looks to be almost certain is the little tube that is (miles) behind the silo.

I am not sure you can ever really know when your pictures are uncertain what you have captured in a case like this.

This is a frame from a Hi8 Camcorder with night shot
zoomed in tight from a good distance during some lighting.

 

[Von Castor]

Well tornado or not, that sounded like 'Hank Hill' (no relation to Roger) in the audio portion! Seriously though, NWS will investigate if you can give accurate location information, at least they have for me in the past.