May 12th 2005 South Plains Tornado / Hail Decision

Note: This post is from a duplicate I posted to Wx-Chase in reply to comments from Dave Lewison which was originally a topic about Threatnet versus other NWS type radar presentation. However I think it is a good case situational study and I wanted to discuss it on StormTrack anyway. It follows:

Dave Lewision said:
> What I'd like to point out is the lack of a useful reflectivity scale. The Tnet shows all purple
> (>55dBz). In our position, we were stopped by downed power poles to the south and the only escape
> was back to the north. But the Tnet was showing this massive wall of purple back that way, so we
> didn't go. Now look at the NWS presentation...the NASTIEST part of the core was actually to our
> West about to nail us. Going north would probably have been a decent escape route with somewhat
> smaller hail.

Nope. It was too late after the initial torn began roping, and when the next multi-vortex began the
core was on top of us. I hung around too long considering following on the east road option when the
RFD / inflow jet to developing tornado (or whatever it was) started up from the west bringing the
large hail with it. With winds roaring as inflow to that larger wallcloud to the east I wasn't
convinced I wasn't possibly under part of a newly developing very large tornado - as sometimes they
can get up to 1 or 2 miles in rare circumstances. (Recall our earlier threads about Hallam). Already
cut off to the south and wallcloud / developing tornado to the east I chose the north option and the
deep core to keep me safe. I knew I would take a pounding (and I did) but figured I wanted out from
under any possible rotation at that point and into the definite downdraft region. Note that as I was
doing this Threatnet was showing about 6 shear markers directly over my area with winds showing up
to 138 - 142 mph. I think in this case most likely once again there was a delay and the area of
shear shown per Tnet and inflow was actually to my east as I made my way north.

Reflecting on this after the fact I think most of us made the wrong choices that day for navigating
this storm's hazards. I think there were two reasonably good choices we didn't make because we were
all directly in front of the eastward moving tornado initially (but north of the east road option)
and we all just stayed around in fascination, and watched it cross the road to our south. Normally
I would choose to be just south of the crossing tornado (near or in the town of South Plains), or I
would stay ahead of it having already gotten on my east road option and kept my distance as the
tornado came out after me.

Instead when the tornado (large white elephant trunk to our west) began developing and finally
developed I could see some high speed wind / dust / rain bands headed across the plowed fields due
southeast of the tornado. It looked like these were headed directly for the town of South Plains.
Last minute I realized my mistake and tried to make that option only to be cut off by the large
tornado looming directly in my windshield probably only a few hundred yards away before I retreated
from my southward folly. I couldn't beat the tornado out. Did anyone see this high wind event
travelling out from the tornadic area? I assume this was RFD related, and might have been
responsible for bringing the power poles down on the highway that Scott McPartland and Dave
mentioned. Alternatively the passage of the torn might have brought them down. These straight line
winds looked troubling and potentially hazardous but possibly doable had I chose that option sooner.
Any opinions on this?

A lot (if not most) chasers chose to follow east on the eastbound road after the stovepipe
diminished. However I got out of my vehicle and looked east. I saw a new even larger wallcloud
stretching north and south directly across the eastbound road. So, chasers were driving directly
under an active, tornado producing wallcloud. I called out on the radio to chasers warning of that
action to no avail. Of course we all know it didn't take long to produce again when it did the
multi-vortex torn; however by then I was more concerned with the giant hail I was encountering. I
really couldn't believe everyone was driving under the wallcloud and whereas I wasn't pleased with
my position or choice there could have been very real consequences had it produced a large tornado
while people were driving under it. The MESO team had the new tornado develop just off the eastbound
road - and not very far away, perhaps only hundreds of feet from accounts I heard, but still was
unable to avoid the hail onslaught.

I think it would have been ok though had we been on the east road earlier when the first main
tornado was initially created and before it came out. Of course it came out pretty quick and it
would take some fast road work to stay ahead of it, but I currently feel this was the BEST option
for seeing the tornadoes, keeping up with new development, and staying relatively safe from the hail
and tornadoes.

Additionally, in retrospect, I would have been better off most likely had I just stopped and turned
the back of the vehicle toward the westerly hail jet and took the pounding from the rear of my Tahoe
which is a fairly long and sturdy structure. My reasoning for not doing this was I wanted to be
further into the core, away from the inflow region, and hopefully find the smaller hail there.
(Unfortunately you have to drive quite a ways (apparently it was miles) to get out of the giant
hail, and the forward momentum of my vehicle made the westerly hail hit my vehicle in the main
windshield from the north side).

It was a wild and crazy chase, and hopefully the dashcam caught some good action including my bid
for getting south of the tornado which was a bit dramatic.

Some memories / pics of my encounter here:
http://www.tornadoxtreme.com/2005_Chases/M...ay_12th_05.html

For those of you out this day, and even those of you who weren't, what are your opinions on the road
options and storm attributes / decisions. Were you close but avoided the hail? What choice would /
did you make?
 
WOW! I showed up a little late that day and I was very lucky. I drove towards the wall from the NW and positioned myself in the bear cage. I actually was filming on the other side of the tornado. When the tornado came down it actually moved south and moved with the wall's rotation before finally turning east. I got really worried when I saw the tornado heading south directly toward a loonngg row of chasers. I zoomed in on the vehicles and they were scattering in reverse trying to get away. Luckily the tornado shifted east just in time. Once it started moving east it grew very large and was running parallel to the road I was on. I got caught in outskirts of the RFD's as they were wrapping around the vortex and manged to stay within a 1/4 mile of the tornado for a good 5 minutes before it roped out. The wall maintained a very mean look and we had to back track over the valley. Once across the valley I decided to pull in a county road and take some more photos of the impressive storm. When it was getting to close to comfort I went to back out and every chaser and their mama was coming down the road in a mile long caravan and I couldn't get on the road until it was too late. Once I got into the town I started getting pelted with golfballs and all the cover was taken. Using Delorme the only options I had was a possible large rain wrapped tornado or Softball size hail. The only other option was a muddy county road in a two wheel drive truck. I went for it since getting stuck would just make an easier decision. Luckily my Nissan Titan has got a ton of power and it is the only thing that kept us from getting stuck. My truck looked like an elephant on ice skates. As we were going south on the CR we got back in position of the wall and it put down several spin ups, but the structure was unreal. I finally came out to a hwy after six miles on that "road". When I came out the storm had taken on a more linear look and I pulled out in front of the OU storm team and about 50 other chase vehicles. WHat a chase!!! I managed to escape with 11 golfballs on my hood and roof and some how my windshield didn't get beat up (I still don't know how). The hail did destroy my bugshield and broke off a plastic piece between my bumper and headlight. There were not too many choices to make that day and no good one's. I made the best choice but only by luck.
 
I was out that day. I was on 207, about a 3/4's of a mile N of South Plains, when I saw the funnel forming. I pulled over and watched in form into a tornado. Once I knew this would last for a bit, meaning growing in size and intensity, I decided to trek just to S to a good EW option at CR 80 but I missed the turn. My reasoning for dropping S was I could see the thick RFD wrapping around and I thought the best visibility of the tornado would be in the inflow region on the SE side.

Anyways, I turned into the first little building just on the N side of South Plains. I sat there for 3 or 4 minutes and filmed the tornado as it approached 207. I stayed there until a little bit after the pic on my avatar. The west side of the tornado was being obscured by the RFD wrapping around and I was loosing visibility of the tornado, so I decided to bust S, plus I was beginning to get RFD'd by wind and small hail. I turned back east on F-M 2286, trying to get a visual on the tornado, I didn't know that by this time the first tornado had dissipated and the second one formed. From this point, I could not see through the muck.

I believe I made the right decisions for myself that day. Another reason that I really don't like to get into large hail is the fact that in my Concorde, the windshields are very horizontial. Very easy for hail to penetrate. Plus, from my vantage point, I got just as good of a view as those who stayed N of the tornado. Also, I escaped hail damage that day. Probably one of the few that did and who got great pics and video.
 
Took the gorilla hail over the tornado, easy choice IMO. The biggest problem in that situation was the lack of road options.
 
Originally posted by Brandon Clement
WOW! I showed up a little late that day and I was very lucky. I drove towards the wall from the NW and positioned myself in the bear cage. I actually was filming on the other side of the tornado. Once it started moving east it grew very large and was running parallel to the road I was on. Once across the valley I decided to pull in a county road and take some more photos of the impressive storm. When it was getting to close to comfort I went to back out and every chaser and their mama was coming down the road in a mile long caravan and I couldn't get on the road until it was too late. Once I got into the town I started getting pelted with golfballs and all the cover was taken. The only other option was a muddy county road in a two wheel drive truck. I went for it since getting stuck would just make an easier decision. Luckily my Nissan Titan has got a ton of power and it is the only thing that kept us from getting stuck. My truck looked like an elephant on ice skates. As we were going south on the CR we got back in position of the wall and it put down several spin ups, but the structure was unreal. I finally came out to a hwy after six miles on that \"road\".

Brandon: You mention you came in from the NW? How did you do this as it was core and developing tornado? Do you mean SW?

Also, which roads and county roads did you take? You mention a town, was it South Plains or another? You decided to take a mud road east correct? What if the tornado which had moved south then east decided to jog south on you again toward the mud road?

I'm just trying to visualize where you were so that I can see what options there were that day. Seems you did ok with your position. You still got the Golfballs but that limited damage and you were still mostly able to follow the storm. Typically I would have been south or east in a position such as yours. I'm wondering how good these small county roads are. Where any of them paved? Delorme 2005 doesn't seem to really show these small roads as good as the Delorme SA 8 used to. They just look inconsequential and unlike road maps which will show by legend either paved or not Delorme does not make that distinction. Consequently sometimes I come up on what looks to be a decent road and it is gravel, or I come up on just another county road and it may be a nice paved road.
 
Originally posted by Justin Walker
I was out that day. I was on 207, about a 3/4's of a mile N of South Plains, when I saw the funnel forming. I pulled over and watched in form into a tornado. Once I knew this would last for a bit, meaning growing in size and intensity, I decided to trek just to S to a good EW option at CR 80 but I missed the turn. My reasoning for dropping S was I could see the thick RFD wrapping around and I thought the best visibility of the tornado would be in the inflow region on the SE side.

Anyways, I turned into the first little building just on the N side of South Plains. I sat there for 3 or 4 minutes and filmed the tornado as it approached 207. I stayed there until a little bit after the pic on my avatar. The west side of the tornado was being obscured by the RFD wrapping around and I was loosing visibility of the tornado, so I decided to bust S, plus I was beginning to get RFD'd by wind and small hail. I turned back east on F-M 2286, trying to get a visual on the tornado, I didn't know that by this time the first tornado had dissipated and the second one formed. From this point, I could not see through the muck.

I believe I made the right decisions for myself that day. Another reason that I really don't like to get into large hail is the fact that in my Concorde, the windshields are very horizontial. Very easy for hail to penetrate. Plus, from my vantage point, I got just as good of a view as those who stayed N of the tornado. Also, I escaped hail damage that day. Probably one of the few that did and who got great pics and video.

Justin: It appears you were very near me initially but slighly further south on hwy 207. You then made the quick choice to go further south and let the tornado cross to your east (one of the options I mentioned). It seems this worked fairly well for you although as expected you eventually lost visual from the wrapping RFD. However you managed to not sustain damage which is cool. It doesn't look like CR 80 goes very far east, but I suppose you could have taken it south, etc at that point had you not missed it. How were these different roads such as 80 and 2286? Were any of them paved?

Also I'm curious what the ride was like in the town of South Plains? Did it end up getting any damage from the tornado or RFD? What made the power poles drop and where were you in relation to them?

Thanks for your input.
 
Originally posted by Shane Adams
Took the gorilla hail over the tornado, easy choice IMO. The biggest problem in that situation was the lack of road options.

Right. I guess what I'm trying to do here is recreate the setup from different vantage points and see how people fared in the different zones. I want to learn from this. We were stuck north of the eastward crossing tornado. Brandon and Justin were apparently around the south option. Still haven't heard from anyone on the early east option which I would consider probably the most desirable. I wonder if anyone did get east early enough to setup and watch the tornado come out and avoid all the hail / wind?

Of course our vantage point was probably the best for quality viewing of the torns but inevitably we get cut off and suffer the consequences. Sounds like south was ok, but somewhat limited the view and the road options may have only primarily been mud nearest the area of interest.

Alternatively the east road (FM 689) would be a good fast road but it does start jogging north and northeast about 6 to 8 miles east of hwy 207. Not sure if this would / could potentially be a problem.

Ok, let's here from someone that was initially on the east road (689) looking west as the tornado came out. How did you fare? Did you have good visibility, photogenic pictures? Did you avoid damage but manage to see all this storm had to offer?

I think I know the answers to these questions but just want to verify.
 
Brandon: You mention you came in from the NW? How did you do this as it was core and developing tornado? Do you mean SW?

Also, which roads and county roads did you take? You mention a town, was it South Plains or another? You decided to take a mud road east correct? What if the tornado which had moved south then east decided to jog south on you again toward the mud road?

I'm just trying to visualize where you were so that I can see what options there were that day. Seems you did ok with your position. You still got the Golfballs but that limited damage and you were still mostly able to follow the storm. Typically I would have been south or east in a position such as yours. I'm wondering how good these small county roads are. Where any of them paved? Delorme 2005 doesn't seem to really show these small roads as good as the Delorme SA 8 used to. They just look inconsequential and unlike road maps which will show by legend either paved or not Delorme does not make that distinction. Consequently sometimes I come up on what looks to be a decent road and it is gravel, or I come up on just another county road and it may be a nice paved road

Bill,
I'm sorry, I came in from the NE (south on 207 then East on 2286) not the NW. I had to pick an intercept point so I stayed just South of the core until after the first tornado. I got hit with golfballs maybe a tad bit larger but managed to get the hell out of there before the gorillas really started falling. No my delorme doesn't show the difference between paved and mud roads and the only option that day was mud roads, gorilla hail or tornado. I'm not positive that all the following roads are exactly right but I'm pretty sure. It was 2286 where I intercepted the first tornado about 2-3 miles west of the canyon. The tornado started off as a cone and came down very close to 2286 and moved south for the first couple minutes before shifting East. I was just north of the tornado going parallel with the tornado heading back west on 2286, at this time it was a large stovepipe. I continued west until it roped out and at that time I was back to the canyon when the second tornado formed but I was right on the canyon and had to cross and never really got to enjow it. My best option was to try and get back to 207 and try and pick another intercept point. When I got to 207 I wanted to go South but did not see any good road choices south of 2286 so I went north towards south plains. Once I was on 207 the storm was very photogenic and I pulled onto a road about a half mile north of 2286 on 207 and took some pics. When I tried to pull back on 207 I was met with a caravan of chasers and had to wait for a couple minutes before I could get back to S. Plains. When I got to the town the hail had just started and the hail was about the size of golfballs and it was pretty neat because the hailstones fell so far apart. As the core was getting closer the hail got larger and was coming down a lot faster. At that point I took cr-179. It was a county road and was muddy as hell and it went south. I knew I had a couple minutes to get south and the county road was built up about 3 feet on each side and it had already started raining so it was extremely slick. I tried to keep it at about 20 mph and had to use the banks on the side of the road a couple of times and there was 0 brakes and very little steering. After a couple minutes there was some gravel mixed in and I got up to about 40mph. The mud road came to T and Delorme had it going straight so luckily I could see it coming and had time to come to a stop. When I got to the T I went east then took cr-189 south then took cr-110 all the way to 97 about 1-2 miles SW of 1065. Cr-110 was a dirt road but it was dry and was not a problem. When I came out to 97 there were probrably 50 chase vehicles. . After that it was getting dark so I called it a day and stopped to get gas where I met Mike Mezeul II in his Nissan Frontier. I headed to Childress and then to Wichita Falls were I got a room and went to sleep before heading home the next morning. I hope that gives you a better idea.
 
Originally posted by Bill Tabor+--><div class='quotetop'>QUOTE(Bill Tabor)</div>
<!--QuoteBegin-Justin Walker
I was out that day. I was on 207, about a 3/4's of a mile N of South Plains, when I saw the funnel forming. I pulled over and watched in form into a tornado. Once I knew this would last for a bit, meaning growing in size and intensity, I decided to trek just to S to a good EW option at CR 80 but I missed the turn. My reasoning for dropping S was I could see the thick RFD wrapping around and I thought the best visibility of the tornado would be in the inflow region on the SE side.

Anyways, I turned into the first little building just on the N side of South Plains. I sat there for 3 or 4 minutes and filmed the tornado as it approached 207. I stayed there until a little bit after the pic on my avatar. The west side of the tornado was being obscured by the RFD wrapping around and I was loosing visibility of the tornado, so I decided to bust S, plus I was beginning to get RFD'd by wind and small hail. I turned back east on F-M 2286, trying to get a visual on the tornado, I didn't know that by this time the first tornado had dissipated and the second one formed. From this point, I could not see through the muck.

I believe I made the right decisions for myself that day. Another reason that I really don't like to get into large hail is the fact that in my Concorde, the windshields are very horizontial. Very easy for hail to penetrate. Plus, from my vantage point, I got just as good of a view as those who stayed N of the tornado. Also, I escaped hail damage that day. Probably one of the few that did and who got great pics and video.

Justin: It appears you were very near me initially but slighly further south on hwy 207. You then made the quick choice to go further south and let the tornado cross to your east (one of the options I mentioned). It seems this worked fairly well for you although as expected you eventually lost visual from the wrapping RFD. However you managed to not sustain damage which is cool. It doesn't look like CR 80 goes very far east, but I suppose you could have taken it south, etc at that point had you not missed it. How were these different roads such as 80 and 2286? Were any of them paved?

Also I'm curious what the ride was like in the town of South Plains? Did it end up getting any damage from the tornado or RFD? What made the power poles drop and where were you in relation to them?

Thanks for your input.[/b]
I don't exactly remember is CR 80 was paved, since I missed it. I wanted to take that road because it would keep me closer to the tornado for two miles or however long it was before it turned south and hooked up with 2286. However, 2286 was paved for about 4 miles until it ended and there was a T. From there, you could only go N or S on dirt roads, not kinda gravely, but pure dirt. So I choose the S option but bc of the style of the road, I booked it S and zig-zaged S and E until I got to CR 110, which was also dirt, but in much better shape. From there I proceded west onto the escarpment. At that point, I met up with the Josh Wurman and the DOW's and goofed around with them showing them the tornado they missed. They only saw it on radar from a distance!!

As far as the ride in South Plains, I bailed S and then east on 2286, just before it crossed 207. The tornado was probably just a 1/4 mile west of 207 and 1/4 N of South Plains. So I missed the big RFD push in town. For the power poles and there relation to me, I believe that they were just N of town, right? If so, then I was about 200-300 meters from them, but they were still standing when I left. I assumed it was the tornado that pulled them down since it crossed the road.

I hope that this helps you, some of the details I forgot...Sorry
 
I guess Kanani and I were some of the few who had no problems avoiding the pitfalls that day. we approached 207 from the east on 689 and set up at thet T intersection about 3-4 minutes before the 1st tornado formed. As it moves ESE towards 207 we moved east staying ahead of the tornado. except for 1 point where we were about 1/4 mile to the NE of the tornado we stayed at least 1 mile ahead of it and were able to avoid the hook wrapping around and the newer circulation developing even though we could clearly see it. The 1 point I want to also make is the new circulation was also south of 689 and the new tornado developed south of 689 by 1/4 - 1/2 mile so the chasers that did head east under the hook I dont think were in any big danger since the storm was moving ESE. The tornado track would take the danger away from them. We filmed both tornados from the ENE and neither posed a threat to people on 689.the bigger danger was the monster hail coming directly down 689 which we were also able to stay ahead of. the biggest we encountered was maybe a few golfballs in quitaque on the intersection of 1035 and 86 as we headed towards Turkey. it was an all around great chase with good video and no damage.
 
Originally posted by Jay McCoy
I guess Kanani and I were some of the few who had no problems avoiding the pitfalls that day. we approached 207 from the east on 689 and set up at thet T intersection about 3-4 minutes before the 1st tornado formed. As it moves ESE towards 207 we moved east staying ahead of the tornado. except for 1 point where we were about 1/4 mile to the NE of the tornado we stayed at least 1 mile ahead of it and were able to avoid the hook wrapping around and the newer circulation developing even though we could clearly see it. The 1 point I want to also make is the new circulation was also south of 689 and the new tornado developed south of 689 by 1/4 - 1/2 mile so the chasers that did head east under the hook I dont think were in any big danger since the storm was moving ESE. The tornado track would take the danger away from them. We filmed both tornados from the ENE and neither posed a threat to people on 689.the bigger danger was the monster hail coming directly down 689 which we were also able to stay ahead of. the biggest we encountered was maybe a few golfballs in quitaque on the intersection of 1035 and 86 as we headed towards Turkey. it was an all around great chase with good video and no damage.

Well that confirms it Jay...as I suspected. Being initially on the east road option (hwy 689) or getting there quick before the tornado came out was the best option of the day for observing the storm, keeping up with the new development, and avoiding its hazards. It probably would have been my choice had I not gotten lulled into watching the fascinating scenario unfolding.

I will have to disagree with you however about the danger posed to chasers on 689 that were initially on 207 after the first tornado dissipated. I was only about 50 to 100 yards north of the intersection of 689 and 207 on hwy 207 and looked due east down 689. From what I could see was the wallcloud extended quite some distance both north and south of 689. I'd estimate at least 1/2 mile each side which makes sense as it had just put down a tornado near road 689. Now it may be true that the circulation and new development ended up being south of the road but that doesn't necessarily make the people safe to drive under the wallcloud. The next tornado could have dropped anywhere under the wall. Perhaps they all realized this and just made a judgement call. I guess my point is it's never very wise driving under an active wall cloud that just produced a big tornado. That should be a given. That said, I suppose there are all sorts of chasers with different motivations and skill levels. Some might have had an objective of being in a tornado to shoot the video. However, I think the "right" way to do it was to be east initially, or get to that position quickly - as you apparently did.
 
I agree to an extent Bill about driving under a wallcloud but the entire wallcloud wasnt rotating. the area of intense rotation where you could tell the next tornado was forming was south of 689. That is why I said the chasers who went east werent in danger. i could clearly see where it was going to develope next as was able to stay ahead and north of it. mY guess is some chasers may have just taken the chance to avoid the hail but I am betting others like me could see the area of concern was south of the road and so decided to get east before it dropped again. Ofcourse I was already moving east before the 1st one even roped out. I prefer to stay well ahead of the tornado. I dont have to be 50 yrds away to get great video.
 
There was very evident rotation across 689, both sides. I don,t know what the east view was like, but looking east from the west, there was rotation straddling the road. Another reason I didn't go east was because we were far enough behind the developing tornado that there was even larger hail just east of our position; by the time I realized we could possibly fly east and avoid the next tornado, the hail east of us was too big to drive into....ask Mickey and Chad. They were maybe .25 miles ahead (east) of us and they got absolutely destroyed, as did Ben Vassmer who was right there with them before turning around and heading back west towards us. We lost our rear window just as Ben was passing us on his retreat; we never did find a golfball or larger stone in the car and the more I think about it the more I suspect wind-driven debris knocked out our back glass. I really don't think chasers screwed up this day so much as there are just no roads out there in that part of Texas. Chasers knew what to do, but they simply had little or no option to act upon that knowledge.

I'm quite content to chalk this day up as a good example of how, sometimes, the danger all chasers mention to muggles when discussing chasing is sometimes very real, and not just a fabrication created in hopes of keeping others from taking up chasing themselves.
 
Shane I am guessing you were a few miles west of us then cause we were always well ahead of any hail core until we stopped at the crossroad that headed north into Quitaque. we didnt even get any precip until then. I guess the chasers you saw head east were also well behind us because we were always east of the rotation. Guess for many it was a choice of danger either way... wall cloud or gorilla hail. I feel fortunate we stayed ahead of both. just glad I didnt have to choose.

This is a pic from the intersection of 207&689 looking west
http://img.photobucket.com/albums/v652/tor...05/Tornado1.jpg

This is about as close as we got before we moved east.. this is looking SW from 689
http://img.photobucket.com/albums/v652/tor...ay122005022.jpg

It was still on the ground when we moved east. the second tornado also developed to our WSW so we were east of the wallcloud the whole time but it was hard leaving the 1st one still on the ground to move and stay ahead of it all.
 
Jay, you guys definitely had the ideal approach to that particular set of tornadoes/occlusions. I'd not seen any images from your angle, those are awesome.
 
Originally posted by Jay McCoy
Thanks. the entire set can be seen at

http://photobucket.com/albums/v652/tornado...dreams/5-12-05/

For some reason they are in backward order. the pics go in reverse time with the end pics being the 1st of the day.

Jay it's interesting that your picture 10 of 34 shows what appears to be a fairly large low hanging funnel directly over hwy 689 to the west as the tornado is in progress just to it's south.

I don't remember how much I saw of that second tornado, but I believe I saw the beginning of it. I was too busy dodging zinging hail stones.
 
Originally posted by Bill Tabor

Jay it's interesting that your picture 10 of 34 shows what appears to be a fairly large low hanging funnel directly over hwy 689 to the west as the tornado is in progress just to it's south.

I don't remember how much I saw of that second tornado, but I believe I saw the beginning of it. I was too busy dodging zinging hail stones.

I can confirm that also. Although I couldn’t tell you if it was rotating or not because, much like you Bill, I was dealing with the hail. I will do some video captures or maybe even a video clip of what is on my video and post them when I get home tonight.
There was the main tornado on the south of the hwy and one (maybe) on the north side also. It was a very chaotic situation. That's why I did not move east.

Mick


Mick
 
Ok I said I would and I did. It just took a while to do it. lol I will try the video later.

Here is one capture. This is looking N.E. on hwy 689 north of the hwy.
20051205.jpg


Mick
 
Interesting. Blurry, but it almost appears there are some weak rotation 'streamers' extending from underneath the main lowered funnel of condensation. Possibly even dust underneath them, but it is very hard to see.
 
Bill posted some of what I wrote on WX-CHASE, but I figured the actual radar image I was referring to would be helpful. It's posted below.

That tornado did some weird things....things I was not expecting. The parent storm was originally moving ENE, but took more of an east or ESE motion as the core appeared to be surging forward, and the storm consequently became outflow dominant a short time later. I believe the tornado was actually moving SW for a time initially, before swinging south, SE and then E, intensifying rapidly. It was rotating around the parent meso. The Attica tornado on 5/12/04 did the same thing, except it formed on the south side of the meso, before swinging E, NE and then N, crossing hwy 160.

Normally, when you're positioned east of a developing tornado and the parent storm is moving ENE, you're pretty safe and in a great viewing position. But this cyclonic "wobbling" caught me off guard. I was not expecting to have to race this tornado southward as it made a bee line towards my only escape route! Does anyone else have examples of these wobbles? Is there a specific term that describes it?

tnet_radar_compare.jpg
 
Dave posts an exellent example comparing level II data to the Threatnet version. As far as I can tell based on my experience using the Threatnet, the data is actually very low-bandwidth data (needed to get through the narrow XM pipe), and consists of a grid similar to the nationally composited Radar Coded Message (RCM) grid, where

1. The grid is a 2 km cartesian grid of "composite reflectivity", or the maximum reflectivity in a vertical column
2. The grid is a "seven level product" (VIP 0 through 6), with "Level 6" being 55 dBZ or greater
3. Radars in clear air mode are excluded
4. The gridded data are treated as grid points which are then smoothed using a very simple scheme in the software to make filled contours.
5. Includes TVS, meso, storm, and hail algorithm info, but unknown which are NWS algorithms and which are Baron algorithms

CG lightning data also seem to be quantized to a 2 km grid.
 
Tornado Wobbles

In reference to question regarding tornado 'wobbles', my experience leads me to generally assume anywhere under the meso circulation is fair game. Not sure if scientific term for such 'wobbling' exists. Much depends on strength of rotation in meso and overall storm motion / speed. I have been in situations not only where tornado took unexpected turn in direction, but other peripheral funnels or tornadoes formed around edge of meso. I believe, historically, these rotations around the meso explain some of the strange paths of destruction aside from any effects of multi-vortex tornadoes. Additionally, somewhat depends upon position within meso tornado forms; center vs. periphery. I agree that in most cases the tornado follows the general track of parent storm as long as associated meso remains as part of parent storm and meso rotation strength remains at moderate level. However, goes without saying, meso occlusions are no longer bound by parent storm path.
 
That tornado did some weird things....things I was not expecting. The parent storm was originally moving ENE, but took more of an east or ESE motion as the core appeared to be surging forward, and the storm consequently became outflow dominant a short time later. I believe the tornado was actually moving SW for a time initially, before swinging south, SE and then E, intensifying rapidly. It was rotating around the parent meso.

Normally, when you're positioned east of a developing tornado and the parent storm is moving ENE, you're pretty safe and in a great viewing position. But this cyclonic "wobbling" caught me off guard. I was not expecting to have to race this tornado southward as it made a bee line towards my only escape route! Does anyone else have examples of these wobbles? Is there a specific term that describes it?

I agree man, it was kinda crazy wasn't it?! At first I was due east of it as it seemed to "sit" in the field and spin. I got out and ran all the way up into the plowed field to get some shots of it. It wasn't long after that those RFD streamers I mentioned were intensifying and I saw I should already probably be south. I really 'punched it' but by then had no chance of getting south of the torn as it was racing out to the SE and then almost E like you said very quickly. It's amazing how fast it did this really. What a gorgeous tornado, and I got to see it way up close too -LOL.

Interesting your concept of it rotating around the meso though Dave. I really hadn't considered that but seems this would explain it's movement and speed to some degree. For a term....well let's see. It's a rotating meso with tornado attached and when it occurs as a chaser you are simply out of luck. How about "screwed"? That pretty much covers it don't you think?
 
Dave posts an exellent example comparing level II data to the Threatnet version.

Nice summary of Threatnet Greg. I'd say it is pretty accurate. Obviously in comparision the Tnet really is smoothed quite a bit and presents different visual information than the standard level 2. I've had a number of encounters and opportunities this season to experience Tnet compared to what I usually use (Weathertap). It provides benefits, but it also presents problems you have to learn to deal with. For example, early on in the season Gene Moore and I were out chasing the day of the Paris, Tx torn. We had about 3 or 4 supercells nearby. We intercepted a nice one that appeared like it was going to tornado, but then the RFD killed it. The storm near Paris actually appeared smaller and weaker at the time; however it really didn't provide any visual clues that it was a more tornadic storm. Had we been looking at Weathertap perhaps we would have made a different decision. I forget, but I assume Tnet was showing some shear markers on the Paris storm. As I recall they were showing a bit earlier and a bit stronger than out storm a county or two to the south.

You have to learn to use it, and even then such as in the South Plains situation you may not have the detail you need (for safety and retreat in this case). Also the time gap between images appears to be a bit old relative to shown GPS position so you have to learn to move the storm mentally ten to fifteen minutes in the direction of current storm movement and provide yourself with a 'buffer'.

I still love Threatnet, but do wish it wasn't smoothed so much.
 
Back
Top