Josh Murfield
EF1
Well I guess this is going to make for an interesting episode of "Storm Chasers" this next season, assuming Reed and his crew are still a part of the show.
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Timmer Aurora Intercept
- Thread starter Ryan McGinnis
- Start date
Mike Hollingshead
I think that idea went out the window with the first tornado intercept in the vehicle this year...or slightly before I guess. Hell wasn't the TIV claiming that at some point as well? Then again I guess all that was said is what it was designed for, not what one was going to do with it lol. A legit intercept score would be interesting between the two. They all got balls, that is for sure. But the radar dude that went with on the Kirksville outing, now he's nuts.
John Farley
Supporter
Research by Schmidlin et al found in tornado site surveys that vehicles were almost never tipped and rarely moved in tornadoes of F2 strength or less on the old Fujita scale. At F3, about half were moved, but only about 1 in 5 tipped.
They also did wind tunnel tests. These suggested that for sedans, winds of 130-150 mph were required to upset a vehicle at most wind angles, although at one angle (diagonally from the rear) as little as 115 mph could upset a vehicle. For a minivan, it took stronger winds. Winds coming at a diagonal angle from the front or rear could upset this vehicle at around 130 mph, but for most angles it took around 160-180 mph to upset a vehicle.
This would suggest to me that it is plausible the wind could have been 138 mph without tipping the vehicle. However, this is NOT an experiment I would want to attempt in any vehicle (unless Sean decides to give me the TIV, lol!).
Link to the Schmidlin et al study:
ams.confex.com/ams/pdfpapers/50675.pdf
They also did wind tunnel tests. These suggested that for sedans, winds of 130-150 mph were required to upset a vehicle at most wind angles, although at one angle (diagonally from the rear) as little as 115 mph could upset a vehicle. For a minivan, it took stronger winds. Winds coming at a diagonal angle from the front or rear could upset this vehicle at around 130 mph, but for most angles it took around 160-180 mph to upset a vehicle.
This would suggest to me that it is plausible the wind could have been 138 mph without tipping the vehicle. However, this is NOT an experiment I would want to attempt in any vehicle (unless Sean decides to give me the TIV, lol!).
Link to the Schmidlin et al study:
ams.confex.com/ams/pdfpapers/50675.pdf
Interesting. I would've thought, with a higher center of gravity, a minivan would be upset with less speed.
This talk reminds me of the famous car flippin tornado video:
http://www.youtube.com/watch?v=Tk4Q7eUoaUY
Jason Foster
That is always fun to watch.....I'm glad they loop the video!
Yes, one has to remember that in a tornado, unlike test winds, or even hurricane winds (to some degree), tornadic winds tend to have a lot of variability. I can say that I've had (or seen) various vehicles in 100+mph winds. In the Hurricane Charley DVD, you can see our view of a Honda Odyssey that stayed put through 145mph winds with gusts possibly up to 175 (unmeasured at that exact location).
Add: However, in the same storm, multiple cars were turned over, including a Dodge Caravan, which was photographed a lot.
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Drew.Gardonia
Reed is crazy. I want to see one of these things in real life, but to me that is just too damn close for comfort. them guys got balls of steel.
Hell if it brings viewers and Discovery Channel gets higher viewing ratings because of it, there's no one at the top who is going to say a word about the actual intent of the use of the vehicle, because this is the kind of stuff people want to see.
Hell if it brings viewers and Discovery Channel gets higher viewing ratings because of it, there's no one at the top who is going to say a word about the actual intent of the use of the vehicle, because this is the kind of stuff people want to see.
David Demko
Greetings everyone! Given the interest in TVN's direct observation of a 138.8 MPH peak wind speed in the Aurora, NE tornado on June 17th, I would like to contribute some background information to the ongoing discussion of this intercept.
The instrument used to measure wind speed and direction on Reed's vehicle (the "SRV") is an R. M. Young marine model wind monitor. This unit is, for all intents and purposes, equivalent to the mechanical R. M. Young wind monitors pressed into operation by the Oklahoma Mesonet, West Texas Mesonet, and mobile mesonet vehicle probes of Vortex/V2, among many other scientific projects, meteorological networks, and chasers alike. As specified by R. M. Young, this wind monitor is accurate to within +/- 0.3 m/s (~0.7 MPH) for wind speeds lower than 30 m/s (~67 MPH) and +/- 1% for wind speeds exceeding 30 m/s up to 100 m/s (~224 MPH). The SRV features an instrumentation mast, extending approximately 2.5 feet above rooftop level, to which the wind monitor is mounted. Presently, the magnitude of any error introduced as a consequence of the wind monitor's location in relation to the body of the vehicle is not well known. Proper siting of the wind monitor, including its position relative to the vehicle's slip-stream, is an issue of consequence to be sure. We have speculated about a handful of potential complications which could conceivably lead to both low and high biases in wind speed measurements under various circumstances. Given the inherent scientific import of in situ measurements taken near ground level in tornadic circulations, sources of potentially significant error in this dataset will certainly need to be formally identified and, if at all possible, adequately quantified before inclusion in literature.
Specifically concerning the 138.8 MPH gust, that measurement was the maximum 1 second average wind speed recorded while the SRV was deployed in a stationary position during the Aurora intercept. The direction of this wind gust was perpendicular to the vehicle from left (driver's side) to right. As is evident in the video (near the 2:08 mark) recorded by the SRV's rooftop "bubble cam" and footage (near the 3:05 mark) from Darin Brunin and Dick McGowan, the vehicle was impacted by a rather vigorous suction vortex at a time coincident with our observation of the 138.8 MPH wind velocity. The front driver's side tempered glass inner window shattered at that moment. Outside an 18 second window of time during which the suction vortex/vortices traversed the SRV, 1 second average wind speeds were entirely lower than 100 MPH.
Insomuch that the SRV wind observations have been referenced in discussions heretofore of the EF scale, note that the wind relationships in the EF scale are based upon 3 second average wind speeds (see TTU, SPC). The peak 3 second average wind speed measured by TVN during the Aurora intercept was 122.4 MPH. That 122.4 MPH 3 second average wind velocity integrates the 138.8 MPH peak 1 second average velocity with two temporally adjacent 1 second average velocities of 131.1 MPH and 97.3 MPH. Adding to the sentiment expressed in earlier posts by other members, generally speaking, I would caution that it is inadvisable to draw significant parallels between the SRV's peak wind measurement, a measurement over a limited temporal and spatial extent, and either the tornado's overall EF scale rating (which is assessed at the location of most significant damage -- a point disparate in both time and space from the SRV's peak wind observation) or visual impressions of tornado intensity.
In all likelihood neither the 138.8 MPH 1 second nor 122.4 MPH 3 second average peak wind speed observations are wholly representative of the horizontal velocities in the Aurora tornado's entire core flow region at the time those measurements were taken. Nevertheless, it seems genuinely reasonable that those measurements are substantially representative of the smaller scale suction vortex we sampled within the larger circulation of the maturing Aurora tornado.
The Aurora tornado and its parent supercell certainly exhibited a fascinating evolutionary progression! In addition to wind monitor measurements of horizontal flow, the CLOVER project was in operation during the intercept and enabled us to sample vertical velocities within the tornadic circulation. The CLOVER data is still being analyzed at this time, and we believe that a good deal of additional knowledge stands to be gleaned from this event.
The instrument used to measure wind speed and direction on Reed's vehicle (the "SRV") is an R. M. Young marine model wind monitor. This unit is, for all intents and purposes, equivalent to the mechanical R. M. Young wind monitors pressed into operation by the Oklahoma Mesonet, West Texas Mesonet, and mobile mesonet vehicle probes of Vortex/V2, among many other scientific projects, meteorological networks, and chasers alike. As specified by R. M. Young, this wind monitor is accurate to within +/- 0.3 m/s (~0.7 MPH) for wind speeds lower than 30 m/s (~67 MPH) and +/- 1% for wind speeds exceeding 30 m/s up to 100 m/s (~224 MPH). The SRV features an instrumentation mast, extending approximately 2.5 feet above rooftop level, to which the wind monitor is mounted. Presently, the magnitude of any error introduced as a consequence of the wind monitor's location in relation to the body of the vehicle is not well known. Proper siting of the wind monitor, including its position relative to the vehicle's slip-stream, is an issue of consequence to be sure. We have speculated about a handful of potential complications which could conceivably lead to both low and high biases in wind speed measurements under various circumstances. Given the inherent scientific import of in situ measurements taken near ground level in tornadic circulations, sources of potentially significant error in this dataset will certainly need to be formally identified and, if at all possible, adequately quantified before inclusion in literature.
Specifically concerning the 138.8 MPH gust, that measurement was the maximum 1 second average wind speed recorded while the SRV was deployed in a stationary position during the Aurora intercept. The direction of this wind gust was perpendicular to the vehicle from left (driver's side) to right. As is evident in the video (near the 2:08 mark) recorded by the SRV's rooftop "bubble cam" and footage (near the 3:05 mark) from Darin Brunin and Dick McGowan, the vehicle was impacted by a rather vigorous suction vortex at a time coincident with our observation of the 138.8 MPH wind velocity. The front driver's side tempered glass inner window shattered at that moment. Outside an 18 second window of time during which the suction vortex/vortices traversed the SRV, 1 second average wind speeds were entirely lower than 100 MPH.
Insomuch that the SRV wind observations have been referenced in discussions heretofore of the EF scale, note that the wind relationships in the EF scale are based upon 3 second average wind speeds (see TTU, SPC). The peak 3 second average wind speed measured by TVN during the Aurora intercept was 122.4 MPH. That 122.4 MPH 3 second average wind velocity integrates the 138.8 MPH peak 1 second average velocity with two temporally adjacent 1 second average velocities of 131.1 MPH and 97.3 MPH. Adding to the sentiment expressed in earlier posts by other members, generally speaking, I would caution that it is inadvisable to draw significant parallels between the SRV's peak wind measurement, a measurement over a limited temporal and spatial extent, and either the tornado's overall EF scale rating (which is assessed at the location of most significant damage -- a point disparate in both time and space from the SRV's peak wind observation) or visual impressions of tornado intensity.
In all likelihood neither the 138.8 MPH 1 second nor 122.4 MPH 3 second average peak wind speed observations are wholly representative of the horizontal velocities in the Aurora tornado's entire core flow region at the time those measurements were taken. Nevertheless, it seems genuinely reasonable that those measurements are substantially representative of the smaller scale suction vortex we sampled within the larger circulation of the maturing Aurora tornado.
The Aurora tornado and its parent supercell certainly exhibited a fascinating evolutionary progression! In addition to wind monitor measurements of horizontal flow, the CLOVER project was in operation during the intercept and enabled us to sample vertical velocities within the tornadic circulation. The CLOVER data is still being analyzed at this time, and we believe that a good deal of additional knowledge stands to be gleaned from this event.
Joshua Nall
EF4
That was an extremely informative write up. Thanks for taking the time.
Josh
Darren Addy
EF5
Jeremy Ludin
EF2
WOW. Not sure how I missed this thread before or how I ever missed the actual VIDEO before, but that was INCREDIBLE. That goes down as one of the best tornado vids I have ever seen. Can't wait to see this chase on Discovery!!
Jason Foster
Thanks for the write up David, I think that reinforces what a lot of folks here were thinking and mentioned....a localized event, and may not have been representative of the tornado as a whole. It is great to have folks post this kind of follow-up on ST.
Ryan McGinnis
EF5
Reed is crazy. I want to see one of these things in real life, but to me that is just too damn close for comfort. them guys got balls of steel.
Hell if it brings viewers and Discovery Channel gets higher viewing ratings because of it, there's no one at the top who is going to say a word about the actual intent of the use of the vehicle, because this is the kind of stuff people want to see.
Hopefully Reed will take this in the playfully humorous spirit that it's meant, but I saw this image posted today in a FARK thread and just about spit my soda all over my monitor:
Skip Talbot
EF5
Yeah, I'm pretty sure he loves that picture because I've seen him use it other places (facebook?). Anyway, the low pressure inside of a tornado causes this effect, in much the same way it did to Arnold Schwarzenegger on Mars during Total Recall:
Rob Wadsworth
EF5
Yeah, I'm pretty sure he loves that picture because I've seen him use it other places (facebook?). Anyway, the low pressure inside of a tornado causes this effect, in much the same way it did to Arnold Schwarzenegger on Mars during Total Recall:
Classic...I'm mad because you did it before I did!!!...lol
There is an uncanny resemblance - isn't there? Amazing...
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D. Hayes
That's hilarious!
I think Reed is just to smart for his own good. I had a buddy once make one a potato canon big enough to fire cantaloupes. He thought it was a good idea.
Reed does act a lot like my kid with adhd. I'm sure I can send him a few pills for his next chase haha! BACKUP!
I think Reed is just to smart for his own good. I had a buddy once make one a potato canon big enough to fire cantaloupes. He thought it was a good idea.
Reed does act a lot like my kid with adhd. I'm sure I can send him a few pills for his next chase haha! BACKUP!
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