Supercell Questions

[Lance Bradshaw]

I've just read a couple of bits of information: that supercells can develop from non-supercell storms and that supercells can exist in squall lines. If that's not true, please do correct me (my sources were Google and Wikipedia).

If that's the case, does that mean that supercell tornadoes and non-supercell tornadoes can coexist in the same storm? Or can a non-supercell tornado develop into a supercell tornado? As an aside, is there a hard dividing line that separates a supercell thunderstorm from a non-supercell storm? Or is there more a gradient between the two and we classify them separately for convenience?

 

[James K]

supercells can develop from non-supercell storms

That one is technically true for most supercells.
At their earlier stages of development, before the mesocyclone has developed, a supercell is just a cell/thunderstorm

and that supercells can exist in squall lines.

Yes, supercells can indeed be embedded anywhere within a squall line (but especially if it forms line-end-vortexes) - those line end cells can even break off into their own storm.

 

[rdale]

does that mean that supercell tornadoes and non-supercell tornadoes can coexist in the same storm

No. It's either a supercell or it isn't a supercell thunderstorm.

Or can a non-supercell tornado develop into a supercell tornado?

No. The parent storm is either a supercell or it isn't.

is there a hard dividing line that separates a supercell thunderstorm from a non-supercell storm?

Yes. If it is rotating, it's a supercell. If the storm is not rotating, it's not a supercell.

 

[Lance Bradshaw]

I thought it would be best to just bump this topic instead of making a new one, since my next questions are related.

Can a tornado come out of a supercell in some part other than the wall cloud? If so, how does that impact the tornado's strength?

 

[James K]

Can a tornado come out of a supercell in some part other than the wall cloud? If so, how does that impact the tornado's strength?

The wall-cloud forms under the mesocyclone / primary updraft ...
Within the is where a tornado is most likely to form but it could also form right near that point. Also depending on environmental conditions there will not always be a wall-cloud (it is afterall just warm humid air condensing before it reaches the main cloud base) ...
There is also the point where a storm is 'cycling' & a new mesocyclone is forming, a tornado could also form under that point, while the old wall-cloud is still visible.

And I kinda remember reading there is the possibility of something like a gustnado forming along the leading edge of the storm.
I know a QLCS can do landspout-tornadoes along its gustfront/leading edge
But don't ever remember seeing if or not a supercell could (thinking maybe not since the leading edge would be all outflow/downdraft, where in a QLCS you have inflow along that point)

 

[Dan Robinson]

A wall cloud is sort of an old colloquialism in severe storms terminology that doesn’t always manifest in the classic way during tornadoes. Some tornadic storms don’t have wall clouds at all. Even when a wall cloud is present, the tornado is sometimes displaced some distance to one side of it.

 

[Jeff Wright]

I seem to remember a blurb in Tornado Video Classics where a storm became tornadic at the same time it became a supercell---for Rasmussen...that was two decades back or so...