Supercell or not ?

[Enzo Todesco]

Hi !

I'm a French stormchaser and last day I chased a violent storm. Are you able to say me if the storm show in the next video is a supercell or not ?

Here is the video : http://www.youtube.com/watch?v=o6fpX_V8GUE

Radar images are not very huge but there is a little rotation. A few minutes later, i see this structure (wall-cloud ?) :

Thank you for your answers and excuse my bad english !

Cordially

 

[Tim Balassie]

re: Supercell or not?

Enzo,

In it's strictest sense, a supercell is a cumulonimbus showing a persistent and deep mesocyclone, the determination of which is thru radar analysis. This analysis can reveal the strength of the mesocyclone, e.g. the existence of a Bounded Weak Echo Region (BWER), mesocyclone depth, etc.

Out in the field there are some visual clues, the most obvious being the physical rotation of the updraft. However, I don't believe that these visual clues alone, other than that stated above, necessarily mean the storm you are looking at is a supercell. For example, non-supercell Cbs can have overshooting tops, flanking lines, wall clouds and the like. As spotters and chasers we look to these attributes, as they ID storms with strong updrafts and thus those with the most severe potential.

Concerning your video and photos I cannot ID your storm as a supercell. So much depends on what processes are taking place - where is the main updraft, what is the cloud motion, what are sfc winds doing, etc. Your storm looks linear to me - no concentrated area of intense updraft but rather a spacially elongated cloud mass (which might even be outflow). Is there a meso in there? Could be. Regarding the lowering, see above.

Personally, I often wonder if the ID of "supercell" is overused.

Tim Balassie-KC9JIB
Kane Co, IL

 

[Enzo Todesco]

Thanks for your answer !

Radar images show that this cell taked place in a squall line, with a small rotation during nearly 15 minutes. I think It's too short to be identified as a supercell.
In France we don't have a lot of weather data (no doppler, no SRV etc), so storm identification is sometimes difficult when the structure is not "perfect".

Your point of view is interesting !
Cordially, Enzo.

 

[Paul Knightley]

We have similar data issues in the UK! Many storms will have some kind of rotation in their lifetimes - the key point is whether it's deep and persistent. However, you don't need a supercell for severe weather, so don't get too hung up in trying to prove it or not!

 

[Jeff Duda]

Personally, I often wonder if the ID of "supercell" is overused.

Tim, I agree wholeheartedly.