Tornado in Taipei, Taiwan May 11 2011

[Jim Saueressig]

Tornado in Taipei, Taiwan May 12 2011

 

[Jeff Duda]

Good find, Jim. Interesting, as the wall cloud was rotating clockwise, and I'm pretty sure the tornado was rotating counter-clockwise. Being in the northern hemisphere, the tornado was cyclonic, but the parent wall cloud was anticyclonic? wtf?

 

[Rob Wadsworth]

Notice too in those videos, that the tube had no/little forward movement.
Had some debris - though.

 

[Jason Harris]

Good find, Jim. Interesting, as the wall cloud was rotating clockwise, and I'm pretty sure the tornado was rotating counter-clockwise. Being in the northern hemisphere, the tornado was cyclonic, but the parent wall cloud was anticyclonic? wtf?

I think you're exactly right (seen best in first video)--I was noticing the same thing and then read your comment!

 

[J Allen]

Withdrawn on correction from Greg.

 

[Olivier Staiger]

..... the wall cloud was rotating clockwise, and I'm pretty sure the tornado was rotating counter-clockwise. Being in the northern hemisphere, the tornado was cyclonic, but the parent wall cloud was anticyclonic? wtf?

I may have bad vision but to me it seems that BOTH the wallcloud/meso AND also the tornado are anticyclonic ! I know , in the northern hemi cyclonic is much more frequent , but anticyclonic is not impossible.

 

[Olivier Staiger]

I may have bad vision but to me it seems that BOTH the wallcloud/meso AND also the tornado are anticyclonic ! I know , in the northern hemi cyclonic is much more frequent , but anticyclonic is not impossible.

here I found a video from much closer of that same tornado and it seems obvious to me that the tornado was ANTIcyclonic !

http://www.youtube.com/watch?v=3PaXT9J9KfQ

comments ?

that is , in my mind, a rare beautiful video of a rare big anticyclonic tornado in northern hemisphere. Keep in mind that Taiwan is way further south than the Great Plains. Taiwan is about same latitude as Cuba.

 

[Greg Stumpf]

This phenomena is not that unusual (anticyclonic supercell, cyclonic tornado), to go to a recent example there was a very fast moving storm on the 05/10/10 that flew through Kansas or OK at 80mph as the left anticyclonic split and produced a cyclonic tornado.

Disagree - a cyclonic tornado with an anticyclonic supercell is about as unbelievably rare a tornado you will ever get. First, only about 2-3% of cyclonic storms will produce an anti-cyclonic tornado pair as the RFD bifurcates the updraft and causes a counter-rotating anticyclonic bookend vortex to the right of the main cyclonic vortex. Then, tornadoes from left-moving anticyclonic tornadoes are extremely rare, and have only been documented in the WSR-88D era about a dozen times, if that. What occurred on 5/10/10 in Oklahoma was the left-moving anticyclonic supercell counterpart to what I first describe: The main anticyclonic tornado had a secondary cyclonic vortex on the counter-rotating cyclonic bookend vortex to the *left* of the main anticyclonic vortex/tornado. That left-moving supercell, near Bray, OK, produced two anti-cyclonic tornadoes, one of which spun off a secondary counter-rotating cyclonic tornado. It has never been documented before, and thus is extremely rare.

That all being said, the Taipei tornado is anticyclonic, under an anticyclonic low-level mesocyclone, and a very stout one to say the least. There are WSR-88Ds in Taiwan, so it would be interesting to get a hold of the archived radar data from that event to see if this came from a left-moving supercell.

 

[Olivier Staiger]

according to more videos I found on youtube, it happened around 1:10 PM local time





in Xindian , a.k.a. Sindian, a town just south of Taipei .
Here is radar
from 12:50 PM http://www.cwb.gov.tw/V6e/observe/radar/Data/MOS_1024N/2011-05-12_1250.MOS3NC.jpg

and 1PM http://www.cwb.gov.tw/V6e/observe/radar/Data/MOS_1024N/2011-05-12_1300.MOS3NC.jpg

and 1.10 http://www.cwb.gov.tw/V6e/observe/radar/Data/MOS_1024N/2011-05-12_1310.MOS3NC.jpg

and 1.20 http://www.cwb.gov.tw/V6e/observe/radar/Data/MOS_1024N/2011-05-12_1320.MOS3NC.jpg

 

[Jeff Duda]

here I found a video from much closer of that same tornado and it seems obvious to me that the tornado was ANTIcyclonic !

http://www.youtube.com/watch?v=3PaXT9J9KfQ

Yep, I see it now. I was wondering that as I watched the first few videos, as the rotation orientation of wispy tornadoes can sometimes be ambiguous to me. The tornado was clearly anticyclonic. That was great up close video, too. Amazing how narrow it was at the ground and how little damage it appeared to be doing, yet with such strong upward motion.

 

[J Allen]

Disagree - a cyclonic tornado with an anticyclonic supercell is about as unbelievably rare a tornado you will ever get. First, only about 2-3% of cyclonic storms will produce an anti-cyclonic tornado pair as the RFD bifurcates the updraft and causes a counter-rotating anticyclonic bookend vortex to the right of the main cyclonic vortex. Then, tornadoes from left-moving anticyclonic tornadoes are extremely rare, and have only been documented in the WSR-88D era about a dozen times, if that. What occurred on 5/10/10 in Oklahoma was the left-moving anticyclonic supercell counterpart to what I first describe: The main anticyclonic tornado had a secondary cyclonic vortex on the counter-rotating cyclonic bookend vortex to the *left* of the main anticyclonic vortex/tornado. That left-moving supercell, near Bray, OK, produced two anti-cyclonic tornadoes, one of which spun off a secondary counter-rotating cyclonic tornado. It has never been documented before, and thus is extremely rare.

That all being said, the Taipei tornado is anticyclonic, under an anticyclonic low-level mesocyclone, and a very stout one to say the least. There are WSR-88Ds in Taiwan, so it would be interesting to get a hold of the archived radar data from that event to see if this came from a left-moving supercell.

First query, while an anticyclonic producing a cyclonic appears to be rare what about the opposite, a cyclonic with anticyclonics?

Stand corrected on the rarity, managed to confuse myself as usual. Greg one thing I would have to query here, how can you claim that the limited first hand observations we have of tornadoes is at all representative of the sample and spectrum of behavior? Even from a damage survey point of view without an indicator (in typically weak tornadoes) it is nearly impossible to identify the rotational direction. While it might be rare might this also be a symptom of the observations being biased towards the right moving storms on days which might also promote the opposite pairing? I wonder if this sample also includes boundary storms, a quick look at the hodograph for this event would leave one very much uninspired, and yet we see a rapidly rotating storm base and a relatively slow rotating tornado. Can we really claim radar coverage over the US (which is still imperfect) as being the only representative location of this being rare? Anyway, probably a side discussion. Closer video confirms the rotational direction so this discussion is somewhat tangential.