Greg McLaughlin
EF5
I am working on some research for the 2013 El Reno tornado and have come across some interesting tidbits of data surrounding some of the specifics with regards to Twistex's fateful impact with the sub-vortex.
Several years ago while going through countless videos on YouTube I came across Jim Bishop's footage shot from I-40 where you see the headlights of Dan Robinson and Twistex as the powerful sub-vortex bears down on them. Their (Bishop's) view is cut off by the Radio Road overpass and once they re-establish their view of the tornado east of Radio Road, the tornado has morphed into a maxi wedge and neither Robinson's or Twistex's headlights are seen again.
Here is a link to the video:
I spent some time looking at the location on Google Earth and even visited the location on two separate occasions and can confirm that you can see vehicle headlights on Reuter Road from I-40 where the video was shot.
There was some speculation that perhaps the headlights were not of Robinson and Samaras, but were of Piotrowski and Marshall who were on Jensen. however, after reviewing both of their videos, the angles don't match up with the Bishop video.
More recently I found a Reddit thread where someone had done a few calculations from the Bishop video and came up with the same results:
Something I find interesting is most research papers and the general consensus is that Twistex was overtaken by the sub-vortex at roughly 23:23-23:24z (6:23-6:24pm) while the Jim Bishop video when compared to synced video found at: El Reno TED suggests Twistex was overtaken by the sub-vortex between 23:21:30-23:22:00z (6:21:30-6;22pm), or a full 1 to 2 minutes before what has been suggested in various research papers and official statements. I am curious if anyone has any thoughts on this.
Something else I found of interest is the evolution of the wall cloud/SVC (streamwise vorticity current) during the life cycle of the El Reno tornado. Initially, the El Reno tornado formed under a distinct wall cloud with a tail cloud/SVC extending to the north. During the first half of the tornado (west of HWY81), the tornado shifted southeast, away from the SVC, as the hook "uncoiled". A large precip core develop around the north side of the tornado and appeared to separate the tornado from the SVC as it approached HWY 81. Check out this incredible footage from Brenden Lindsey as he raced south to stay ahead of the tornado as it approached 81. He had a perfect view of this exact evolution.
Is it possible that the density current from this precip core, as it rotated cyclonically around the north, then west side of the tornado, shoved it east across HWY 81 causing it to accelerate?
East of HWY 81 the main sub-vortex began to turn left to the northeast and merged back into the wall cloud/SVC. The hook recoiled to the north. Perhaps the intense low-level updraft with the SVC acted like a giant vacuum and pulled the sub-vortex into it in a prolate cycloid looping motion. Twistex was under the SVC which is why they weren't experiencing any rain, and could be why Tim commented that they were in a bad spot.
Anyway, these are a few observations I have made from researching this tornado. Please share your thoughts and questions. I would love to get more discussion going about this tornado, especially with the 10 year anniversary coming up next year.
Several years ago while going through countless videos on YouTube I came across Jim Bishop's footage shot from I-40 where you see the headlights of Dan Robinson and Twistex as the powerful sub-vortex bears down on them. Their (Bishop's) view is cut off by the Radio Road overpass and once they re-establish their view of the tornado east of Radio Road, the tornado has morphed into a maxi wedge and neither Robinson's or Twistex's headlights are seen again.
Here is a link to the video:
I spent some time looking at the location on Google Earth and even visited the location on two separate occasions and can confirm that you can see vehicle headlights on Reuter Road from I-40 where the video was shot.
There was some speculation that perhaps the headlights were not of Robinson and Samaras, but were of Piotrowski and Marshall who were on Jensen. however, after reviewing both of their videos, the angles don't match up with the Bishop video.
More recently I found a Reddit thread where someone had done a few calculations from the Bishop video and came up with the same results:
Something I find interesting is most research papers and the general consensus is that Twistex was overtaken by the sub-vortex at roughly 23:23-23:24z (6:23-6:24pm) while the Jim Bishop video when compared to synced video found at: El Reno TED suggests Twistex was overtaken by the sub-vortex between 23:21:30-23:22:00z (6:21:30-6;22pm), or a full 1 to 2 minutes before what has been suggested in various research papers and official statements. I am curious if anyone has any thoughts on this.
Something else I found of interest is the evolution of the wall cloud/SVC (streamwise vorticity current) during the life cycle of the El Reno tornado. Initially, the El Reno tornado formed under a distinct wall cloud with a tail cloud/SVC extending to the north. During the first half of the tornado (west of HWY81), the tornado shifted southeast, away from the SVC, as the hook "uncoiled". A large precip core develop around the north side of the tornado and appeared to separate the tornado from the SVC as it approached HWY 81. Check out this incredible footage from Brenden Lindsey as he raced south to stay ahead of the tornado as it approached 81. He had a perfect view of this exact evolution.
Is it possible that the density current from this precip core, as it rotated cyclonically around the north, then west side of the tornado, shoved it east across HWY 81 causing it to accelerate?
East of HWY 81 the main sub-vortex began to turn left to the northeast and merged back into the wall cloud/SVC. The hook recoiled to the north. Perhaps the intense low-level updraft with the SVC acted like a giant vacuum and pulled the sub-vortex into it in a prolate cycloid looping motion. Twistex was under the SVC which is why they weren't experiencing any rain, and could be why Tim commented that they were in a bad spot.
Anyway, these are a few observations I have made from researching this tornado. Please share your thoughts and questions. I would love to get more discussion going about this tornado, especially with the 10 year anniversary coming up next year.