New tornado research

[TriPol]

https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/432399

The coupled visual and near-surface radar observations enable an analysis of the tornadogenesis process that has never before been obtained, providing a missing link in the story of tornado formation: the rotation associated with the tornado was clearly present at the surface first. 

[bdgwx]

I've seen media outlets trying to sell this publication as an epiphany by researchers as if the bottom-up hypothesis is somehow new and surprising when it actually isn't.

Trapp and Davies-Jones did research on the topic back in the 1990's. The jargon in use for the top-down model is often referred to as the Dynamic Pipe Effect. They called this type of genesis Mode I. The other type they examined was where there was sufficient low level vorticity already in place to make the tornado form either at all levels simultaneously or even at the surface first (bottom-up). They called this type of genesis Mode II.  I think what is new here is that whereas Trapp and Davies-Jones felt that DPE was important (though maybe not necessarily mandatory) in supercell tornadoes based on numerical simulations this publication is presenting observational based evidence that of the tornadoes they reviewed (one being the El Reno tornado) they all appeared to form as Mode II.

Here is that Trapp and Davies-Jones paper I referred to.

https://journals.ametsoc.org/doi/10.1175/1520-0469(1997)054<0113%3ATWAWAD>2.0.CO%3B2 

 

 

[TriPol]

23 minutes ago, bdgwx said:

I've seen media outlets trying to sell this publication as an epiphany by researchers as if the bottom-up hypothesis is somehow new and surprising when it actually isn't.

Trapp and Davies-Jones did research on the topic back in the 1990's. The jargon in use for the top-down model is often referred to as the Dynamic Pipe Effect. They called this type of genesis Mode I. The other type they examined was where there was sufficient low level vorticity already in place to make the tornado form either at all levels simultaneously or even at the surface first (bottom-up). They called this type of genesis Mode II.  I think what is new here is that whereas Trapp and Davies-Jones felt that DPE was important (though maybe not necessarily mandatory) in supercell tornadoes based on numerical simulations this publication is presenting observational based evidence that of the tornadoes they reviewed (one being the El Reno tornado) they appeared to form as Mode II.

Here is that Trapp and Davies-Jones paper.

https://journals.ametsoc.org/doi/10.1175/1520-0469(1997)054<0113%3ATWAWAD>2.0.CO%3B2 

 

 

Forgive my novice question here, but what about funnel clouds that never touchdown?

[bdgwx]

8 hours ago, TriPol said:

Forgive my novice question here, but what about funnel clouds that never touchdown?

Those are probably top-down I'm guessing.