I need a ruling...

[ngjere]

Or at least an explanation.

Take a look at the radar scan. I originally called the signature WSW of Sand Springs a debris ball. Now, I'm not so sure.

It's definitely an increase in velocity yet not really (as the radar sees it) associated with the differential velocity couplet. Could this be the effect of a microburst?

 

[James Gustina]

You won't be able to directly tell based off velocity. That just looks like strongest point of the RFD relative to the circulation but I could be wrong. Do you have any grabs of the CC at the same time?

 

[ngjere]

Unfortunately, I don't. I didn't notice this until after the event was well over for the area. Thus, my question. I suppose I can grab the archive files later. I just thought there'd be a quick answer...

 

[Michael R.]

From what I can tell, yes. The time stamp matches up perfectly with the SS Tornado. I'd say it is, yes.

 

[Jeff Duda]

Debris balls are generally only defined as reflectivity signatures, not velocity signatures or dual-pol signatures. It is wise to use velocity and CC to corroborate whether a local maximum of reflectivity is indeed a debris ball, but by definition there is no debris ball in the image in the original post. So I can't make a ruling for you.

 

[Isaac Pato]

I echo what's been said above, there is no debris ball in that image because debris balls are a reflectivity feature, not a velocity feature. Your velocity grab does, however, show a TVS (tornado vortex signature).

Below is a 4-panel chart of the KINX SAILS scan from 2236z (same time as OP's velocity grab). Clockwise from top left: Reflectivity, Velocity, Correlation Coefficient, Storm Relative Velocity. I would say that there is no debris ball at this time because there is no significant local dBZ maxima coincident with the TVS.

The base scan from 2234z shows both a stronger TVS and a clear TDS (Tornado Debris Signature), as noted by low CC values coincident with the TVS. There is still no debris ball on this image. The lack of a debris ball tends to indicate (a) that this tornado is relatively weak, and/or (b) that this tornado did not loft significant volumes of debris into the air.