Tornado/Funnel/Shelf???

[Ben_Jacobi]

I was out chasing in Iowa Park, TX on saturday and caught this short video of a possible tornado/funnel/shelf. I actually have no idea what it is and was hoping if y'all might be able to answer the question. Here is what I do know.

There is a distinctive lowering from the base of the storm/possible wall cloud.

The storm is aproximately 10miles to my northeast I am just to the sw of it.

I believe the storm was occluding and during so formed this feature.

I believe I can see part of the RFD coming through around 15sec into the video with contrast enhanced.

Burkburnett (the city it would be closest to) reported a 70mph wind gust. My guess is RFD/straightline winds.

I have also attached radar images with velocity scans. It would really help me out because I have no Idea what to call it. LOL. Right now I am stuck between funnel/shelf cloud. Let me know if you need a higher res video.

Thanks.

-Ben

http://www.youtube.com/watch?v=6oRlRk1Cqus

 

[Nicholas_Scherber]

without an visible ground circulation, i wouldn't call it a tornado. It looks to me like it could be a funnel but there doesn't seam to be a lot of motion with it in your video. Its hard to tell on that video though.

 

[Skip Talbot]

That's going to be tough to say for sure just going off that video. That feature looks quite a bit closer than 10 miles away, even if you're zoomed in some. I assume when you say the storm was to your northeast, that you're also looking northeast. If that's the case, the lowering looks like its angled away from the storm and to the east. That would suggest to me that's an outflow driven feature and the edge of a shelf or whale's tooth. The structure around the feature looks a bit like a whale's mouth too, although its not very well defined. If the feature is pointing off to the north/northeast, it could be an inflow based feature, in which case I'd say its probably a tail cloud that's missing the main body of a wall cloud (or the wall cloud is obscured). Although funnels can point ahead of the storm, they generally have a more vertical orientation or point toward the back of the storm. You really need to see rapid rotation to call it a funnel though, or at least see it rapidly developing. Funnels shift in shape and size quite rapidly, usually within seconds. If you can't tell what it is though, and I'm not sure we can be definitive just going off this video, I would simply call it a lowering. If reporting that on the radio, I'd simply say "pointy lowering, unable to discern rotation or be more specific as to what type of lowering."

 

[J Tyler]

Hey Ben. Throw a set of binoculars in your chase go bag. When it is something at a distance like that, the binoculars will REALLY help you to look and see if there is circulation or not. I've also cheated and used the screen on my camcorder to zoom in because the camcorder is able to do a better job with CONTRAST than my eyes can. Just like how you adjusted the contrast on the video you posted, my camcorder can automatically adjust for that on the fly and help me see things there that I can't with the naked eye.

Skip has (as usual) a ton of great info in his post, and I have to agree that the feature looks to be closer than 10 miles.

 

[Ben_Jacobi]

without an visible ground circulation, i wouldn't call it a tornado. It looks to me like it could be a funnel but there doesn't seam to be a lot of motion with it in your video. Its hard to tell on that video though.

No debris cloud/rotation that I could tell. Thank you.

That's going to be tough to say for sure just going off that video. That feature looks quite a bit closer than 10 miles away, even if you're zoomed in some. I assume when you say the storm was to your northeast, that you're also looking northeast. If that's the case, the lowering looks like its angled away from the storm and to the east. That would suggest to me that's an outflow driven feature and the edge of a shelf or whale's tooth. The structure around the feature looks a bit like a whale's mouth too, although its not very well defined. If the feature is pointing off to the north/northeast, it could be an inflow based feature, in which case I'd say its probably a tail cloud that's missing the main body of a wall cloud (or the wall cloud is obscured). Although funnels can point ahead of the storm, they generally have a more vertical orientation or point toward the back of the storm. You really need to see rapid rotation to call it a funnel though, or at least see it rapidly developing. Funnels shift in shape and size quite rapidly, usually within seconds. If you can't tell what it is though, and I'm not sure we can be definitive just going off this video, I would simply call it a lowering. If reporting that on the radio, I'd simply say "pointy lowering, unable to discern rotation or be more specific as to what type of lowering."

Thank you, Skip. After your analysis I have to lean more towards shelf cloud lowering. I think I got excited about the shape and didn't pay attention to the scud and whales mouth structure. A good portion of this storm was obscured by rain. New cells kept developing downwind of the storm. There was a TVS on radar at the time and the velocity scans looked pretty impressive. It did not last very long as it was quickly swallowed by the rain. I should have been more accurate with the distance, I apologize, but I can't recall how far away I was. I did zoom in pretty good (about 15x) however.

Hey Ben. Throw a set of binoculars in your chase go bag. When it is something at a distance like that, the binoculars will REALLY help you to look and see if there is circulation or not. I've also cheated and used the screen on my camcorder to zoom in because the camcorder is able to do a better job with CONTRAST than my eyes can. Just like how you adjusted the contrast on the video you posted, my camcorder can automatically adjust for that on the fly and help me see things there that I can't with the naked eye.

Skip has (as usual) a ton of great info in his post, and I have to agree that the feature looks to be closer than 10 miles.

Thanks Jeff. I have a pair of binoculars but I didn't bring them with me on this chase. To be fair, I wasn't expecting to chase that day.