Here you go, folks. I'd also like to thank George again for putting these together, presenting the questions this time, and his enduring patience through complications and frustrations. It is appreciated, George.
21:51:05] <@GeorgeT> <SA> "Regarding the accuracy/validity of DOW windspeed measurements in tornadoes, did the downplaying of the 318mp reading on 3 may 99 have anything to do with the media frenzy it created? I ask because I read years ago that the 246mph measurement taken on 30 May 98 of the Spencer, SD tornado was used to actually HELP validate the F-scale windspeed estimations
[21:51:32] <JoshWurman> Well, first, the DOW measurement has to be compared very carefully to
[21:51:58] <JoshWurman> other measurements. It is a radar measurement taken well above the ground, in this case about 150 feet. So, comparing to a wind
[21:52:19] <JoshWurman> at building height is challenging. Our more careful reported measurement is
[21:52:31] <JoshWurman> 301 mph +/- 20. It is important to keep in mind that all measurements
[21:52:48] <JoshWurman> have this type of uncertainty. The 231 mph on Mt. Washington should have
[21:53:01] <JoshWurman> some kind of +/- attached, but it seems to be not reported.
[21:53:18] <JoshWurman> I have not "downplayed' the measurement per se, but certainly do not focus
[21:53:30] <JoshWurman> on it since the exact highest wind that we've measured is of less scientific interest
[21:53:46] <JoshWurman> than the overall structure of tornadoes or how they form.
[21:53:57] <JoshWurman> The other thing to remember about high resolution radar measurements is
[21:54:10] <JoshWurman> that they represent very very short gusts. The 301 mph is a 1/5 second gust.
[21:54:24] <JoshWurman> The corresponding 3 sec gust would be signficantly lower.
[21:54:35] <@GeorgeT> interesting
[21:54:49] <@GeorgeT> <Chief`Skyreader> The 319 speed was an ave was it not... If I recall 285-225 and the 319 was an ave speed... Just curious there.. but question is... that was at 600'... What is the height of the max wind of a torndo? And how fast might it build up? Say rooftop? 25'
[21:55:21] <JoshWurman> I'm not sure what you're saying about 319 mph. Our measurement was
[21:55:37] <JoshWurman> 301 mph +/- 20. Now, I'm sure that some very short gusts, or some pieces
[21:55:51] <JoshWurman> of gravel/debris were moving 320, 340, etc., and some were moving 280, 260 etc.
[21:55:59] <JoshWurman> That is the nature of turbulent flow.
[21:56:14] <JoshWurman> As to the height of the maximum winds, we do not know. We believe that it is
[21:56:34] <JoshWurman> below about 300 feet, and may be near 100 feet. But there are not enough
[21:56:43] <JoshWurman> definitive measurement to say for sure.
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[21:56:58] <JoshWurman> MOderator: Should I use or avoid carraige returns when I type long replies?
[21:57:30] <@GeorgeT> Josh, you may type a message as long as you wish
[21:57:33] <@GeorgeT> it will support it
[21:58:02] <@Chief`Skyreader> (should hear a click click click on PC speaker if exceeding like 512? chars...
[21:58:09] <@GeorgeT> yeah
[21:58:20] <@Caleb> Indeed
[21:58:41] <@Chief`Skyreader> yes 512...
[21:58:45] <@GeorgeT> Ok, next questions
[21:59:03] <@GeorgeT> <NightHawk> How is the phased array mobile radar different than your doppler radar?
[21:59:40] <JoshWurman> A phased array radar uses a series of emmitters rather than a single source of energy
[21:59:59] <JoshWurman> So, the Rapid-Scan DOW, which has an array of about 9000 emmitters arranged on
[22:00:19] <JoshWurman> 106 waveguides, can change the direction of its beam by changing frequency.
[22:00:54] <+JoshWurman> In this manner we send out 6-12 simultaneous beams, literally raking the sky 6-12 times rather than just once per sweep.
[22:01:15] <+JoshWurman> So, each time the antenna goes around, it gets a 3D scan. We've used this in 2003, and
[22:01:30] <+JoshWurman> less successfully in 2004 (despite all those tornadoes) to collect true 3D snapshots
[22:01:37] <+JoshWurman> in rapidly changing tornadoes.
[22:01:55] <+JoshWurman> Many military radars are phased arrays since active phased arrays (much more
[22:02:15] <+JoshWurman> expensive than the passive-phased-array technique we use) can point first one
[22:02:29] <+JoshWurman> place, then the other, which is very useful is one is tracking, say, several incoming
[22:02:34] <+JoshWurman> missiles or aircraft.
[22:03:01] <@GeorgeT> <ef> What did you learn from the investigations of using the DOWs on Hurricane Frances and Ivan
[22:03:21] <+JoshWurman> Not to park too close to the cliff.
[22:03:46] <+JoshWurman> Seriously, though, we are only early in our investigations. We are looking into correlating
[22:04:02] <+JoshWurman> specific wind gusts with particular areas of damage. We collected very high res data
[22:04:21] <+JoshWurman> over Hutchinson Island including the nuke, the causeway trailer park, which had
[22:04:37] <+JoshWurman> major damage, and a series of condos on the barrier island that may have
[22:04:49] <+JoshWurman> affected the winds in ways we can see with the radar. It is a very exciting
[22:05:05] <+JoshWurman> data set.
[22:05:19] <@GeorgeT> <Mike_H> If you can see a tornado vortex with the DOW, is there a height were it usually becomes less defined and/or ends? What height is this typically if this can be seen? If you can't at what height on average does it become less viewable via the radar?
[22:05:44] <+JoshWurman> Above about 2 km (1.2 miles), well into the cloud, the circulation becomes very
[22:06:00] <+JoshWurman> confusing and merges, usually, with the parent mesocyclone.
[22:07:05] <@Chief`Skyreader> (might help to do an 'end' or such when done with the answer Josh)
[22:07:14] <+JoshWurman> okay. end
[22:07:14] <@GeorgeT> <Chief`Skyreader> You've noted eddies in the boundry of the RFD, no? I wonder if "the blob" could be seen coming down and if so, if this kicks off any eddies along the RFD boundry?
[22:07:15] <@Chief`Skyreader> (oops Dr Wurman)
[22:07:36] <@Chief`Skyreader> Eri*'s 'blob'...
[22:07:40] <+JoshWurman> Well, I believe that Erik Rasmussen was in this forum recently, and he is the
[22:07:57] <+JoshWurman> the main proponent of the blob. The blob, as I understand it, originates at
[22:08:16] <+JoshWurman> much higher levels than we usually scan with the DOWs. We get great resolution
[22:08:32] <+JoshWurman> by being up close, but lose vertical persepective, usually seeing only about
[22:08:57] <+JoshWurman> 2-6 km above the ground. We do see intense small scale vortices, I've been
[22:09:18] <+JoshWurman> calling them genesis vortices, along the gust front, and sometimes these appear
[22:09:40] <+JoshWurman> to spiral into, and perhaps congeal to form, a developing tornado. We are
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[22:10:03] <+JoshWurman> just beginning an analysis effort into the role of these small vortices and it will
[22:10:14] <+JoshWurman> be led by Yvette Richardson at PSU. end
[22:10:26] <@GeorgeT> Hi Guest56......type /nick JohnDoe to change name
[22:10:30] <@GeorgeT> <FrankM> What about reports of their being recorded wind speeds of Mach 1 generated by tornados? Any truth to those?
[22:10:30] <@GeorgeT> <FrankM> And if there were any recorded wind speeds of mach 1 reported, which tornado produced that wind? Anything specific that would cause that tornado to reach speeds of Mach 1?
[22:10:53] <@GeorgeT> being Mach 1 at sea level in around 725 mph, I doubt those are true....but an interesting Q nonetheless
[22:11:00] <@Chief`Skyreader> (ahhh I see... too far overhead... need more funding to get a 2nd range truck going... thank you...
)
[22:11:01] <+JoshWurman> No measurements of winds anywhere near M1 have occured. There have been
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[22:11:17] <+JoshWurman> theoretical (Fieldler) and numerical (Llewelen) studies that have suggested that
[22:11:31] <+JoshWurman> M1 may be possible. But, if true, it may be in very small regions that we have
[22:11:49] <+JoshWurman> not resolved with even high res DOW radars. end
[22:12:16] <@GeorgeT> ok gang, I'm outta questions
[22:12:25] <@GeorgeT> feel free to PM me some new ones
[22:12:28] <@Chief`Skyreader> my pebble question to fill in gt
[22:12:46] <@Chief`Skyreader> Around Dallas water is costly... and so a few folks have put large areas of their front lawn with golfball sized stream pebbles... Might this be a bad idea?
[22:13:13] <+JoshWurman> Well, I"m not sure that I'd want to be downstream in a tornado. However, since
[22:13:25] <+JoshWurman> the mean recurrance interval of tornadic winds over any particular lawn, even
[22:13:34] <+JoshWurman> in Dallas, is about 2000+ years, I wouldn't worry.
[22:13:52] <+JoshWurman> end
[22:14:00] <@GeorgeT> <Mike_H> In your opinion which plains state is the best tornado state?
[22:14:15] <@GeorgeT> BTW Josh, just let us know if you get tired of typing
[22:14:19] <@GeorgeT> hehe
[22:14:32] <+JoshWurman> Best to live in or best for intercepts? I assume that you men the latter. In this
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[22:14:51] <+JoshWurman> case, we prefer the flat areas of TX SW of AMA and NW of LBB and also
[22:15:06] <+JoshWurman> various flat areas of Kansas. It is much easier for us to find good radar sites there.
[22:15:07] <+JoshWurman> end.
[22:15:21] <@GeorgeT> <ef> Any progress on the Bistatic Radar Networks
[22:15:39] <+JoshWurman> Not much progress on bistatic networks mainly because I've been focusing
[22:15:51] <+JoshWurman> on the DOWS and recently the rapid-scan DOW. The bistatic technique
[22:16:08] <+JoshWurman> has proved viable and there are recent papers by Friedrich and also by Satoh
[22:16:28] <+JoshWurman> that have analyzed data. Unless there is a champiion for a new technology, it takes a long time
[22:16:39] <+JoshWurman> for it to catch on. I need a clone. end
[22:17:23] <@Chief`Skyreader> That can be done now...
[22:17:29] <@Chief`Skyreader> clone...
[22:17:29] <@GeorgeT> <ef> What has been learned from project IHOP?
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[22:17:59] <+JoshWurman> IHOP: Lots has been learned, but much remains. There is a special issue of MWR coming out in a few
[22:18:23] <+JoshWurman> months that will have several papers. I've been working mainly with the PSU group to examine how different
[22:18:44] <+JoshWurman> boundaries affected convective initiation and how misocyclones, small 1-2 km scale cyclones
[22:19:04] <+JoshWurman> focused uplift and may have been related to CI. Unfortunately, there were not a lot of CI cases
[22:19:32] <+JoshWurman> in IHOP, so it may prove difficult to draw general conclusions. What one winds up with in the absence
[22:19:58] <+JoshWurman> of lots of cases, are individual case studies, eg. how CI happened or didn't in a particular case.
[22:20:18] <+JoshWurman> We were once in the same situation with DOW-observed tornadoes. But, now, with about
[22:20:36] <+JoshWurman> 100 cases we are starting to be able to tackle more general questions. For example
[22:20:55] <+JoshWurman> are there broad classes of tornadoes, do their evolutions vary, are there different
[22:21:03] <+JoshWurman> modes of tornadogenesis, etc. end.
[22:21:10] <@GeorgeT> Here's an interesting question:
[22:21:16] <@GeorgeT> <Mike_H> In your view has the increase in chasers slacked off, or does it seem to still be increasing(judging by how many following the dows I suppose)?
[22:21:50] <+JoshWurman> There were a lot of chasers out in 2004. I think it was more than in 2003 based on the
[22:22:05] <+JoshWurman> peak crowds on some days and several times in hotel parking lots and other loitering areas before
[22:22:24] <+JoshWurman> the weather got active. So far we have not really had a problem with crowds. I know there is always
[22:22:43] <+JoshWurman> concern among the scientific teams, but I personally have not seen a problem. So long as people
[22:23:06] <+JoshWurman> are reasonable, get off the road, etc. we're find. My main pet peeve on the road are the occassional
[22:23:29] <+JoshWurman> chasers who are not sensitive to the acceleration problems that the DOWs have. Please don't
[22:23:48] <+JoshWurman> get right in front of us on a downhill. We're trying to get all the speed we can to get up the next ridge.
[22:23:50] <+JoshWurman> end.
[22:24:10] <@GeorgeT> I'll ask a question picking up where Mike's left off: It is my understanding that some chasers with those portable, "marine" radars interfered with the DOW's on occasion in the past. With the introduction of XM radio and WxWorx, do you see fewer of these marine radars in use?
[22:24:27] <+JoshWurman> I hope so.
[22:24:42] <+JoshWurman> WX is a great product. Sure it is blurred somewhat, and can be few minutes out of date, but
[22:25:00] <+JoshWurman> it is probably much better information that what was coming out of the marine radars anyway.
[22:25:19] <+JoshWurman> I'm glad to say that we did not see much X-band interference in 2004.
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[22:25:31] <+JoshWurman> end
[22:25:39] <@GeorgeT> <Chief`Skyreader> Four times now since 2000, I've seen, in my view finder of my Canon GL1, a condensation funnel in a core in the center of the wall cloud. These funnels where NOT visible to the naked eye! In one, Foss Lake tornado, the core let up and the tornado appeared quite fully formed as a trunk... Question is... Have you seen any, what I'd call TVS, signatures in visible cores? 1 outa 4 had a boni fidi tornado, but I wonder if that was
[22:26:11] <@Chief`Skyreader> (the CCDs filter UV or ???? but they was there...)
[22:26:18] <+JoshWurman> Well, a condensation funnel occurs whenever the pressure gets low enough for
[22:26:37] <+JoshWurman> condensation. In a complex flow field, it is possible that several such funnels could
[22:26:55] <+JoshWurman> exist. The DOWs see very complex flow fields in some situations and it is surprising
[22:27:09] <+JoshWurman> to mee that more sundry funnels are not seen. I would think that the
[22:27:23] <+JoshWurman> small scale vortices that we see could make funnels, for example. In other
[22:27:44] <+JoshWurman> cases we see what I would say are mutliple-vortex mesos, but the smaller
[22:27:59] <+JoshWurman> vortices are not really tornadoes. By the way, defining what is and what is not
[22:28:13] <@Chief`Skyreader> (These extended sfc to where cut off due to arcus of wall cloud
[22:28:22] <+JoshWurman> a tornado does not become easier with extra data. There are often cases which
[22:28:40] <+JoshWurman> are very unclear. We were north of Geary, OK last May, in a region that was
[22:28:58] <+JoshWurman> fairly opaque visually due to blowing dust. In the radar, we could see several short
[22:29:15] <+JoshWurman> lived, intermittent, but certainly tornadic strength vortices. Some of these we decided
[22:29:29] <+JoshWurman> were tornadoes, based on continuity. There is still somewhat of a debate concerning
[22:29:47] <+JoshWurman> whether the 2-3 km scale circulation which DOW3 had the misfortune of sampling
[22:30:04] <+JoshWurman> directly, was a tornado containing a single multiple-vortex, or whether the larger
[22:30:26] <+JoshWurman> circulation was simply a surface meso enhanced on the S side by the RFD. In
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[22:30:53] <+JoshWurman> any case, winds at 12 m above the ground were 87 m/s, nearly 200 mph.
[22:31:20] <+JoshWurman> The inner "tornado" had winds of only 65 m/s. We would have been more
[22:31:31] <+JoshWurman> happy in the tornado than where we stopped. end
[22:31:34] <@GeorgeT> OK, we've been asking questions for what I guess has been close to an hour. So we might want to start winding this down. One or two more questions and I'm going to un-moderate the room and allow you to chat freely with Dr. Wurman, that way he isn't required to do all the chatting. And Dr. Wurman, feel free to take a break if you need one and end whenever you are ready.
[22:31:41] <@Chief`Skyreader> wow... on 200... TY
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[22:31:54] <@GeorgeT> <Mike_H> Did the dow data show anything interesting about the May 24, 2004 sc NE tornadoes? That storm was simply not happy unless it had a tornado down and just wondered if there were any clues on that setup as to why that might have been.
[22:32:25] <+JoshWurman> We have just received a large collaborative grant, with PSU and OU and NCAR to begin analyzing
[22:32:43] <+JoshWurman> the 2004 data. David Dowell at OU/CIMMS will be leading the analysis of the 24th. It is a
[22:33:00] <+JoshWurman> very interesting case with a front interacting with the storms. The storm motion really messed
[22:33:16] <+JoshWurman> up our dual-Doppler deployments, complicating our analysis. However the storms, as you mentioned
[22:33:28] <+JoshWurman> were quite prolific tornado producers. end.
[22:33:34] <@GeorgeT> <ef> In VORTEX 2, what do you want to accomplish with the DOWS and other radars
[22:33:34] <@GeorgeT> <ef> <ef> When will ROTATE 2005 begin and for how long
[22:33:55] <+JoshWurman> With VORTEX2, we hope to use several mobile radars, perhaps about 7 to study various
[22:34:15] <+JoshWurman> scales. (btw, you can go to
www.vortex2.org for some info. the site is not fully up and there
[22:34:30] <+JoshWurman> are some missing links, but it will contain the most recent updates). We hope
[22:34:44] <+JoshWurman> to use the SMART radars to sample the complete supercell, then DOWs to sample
[22:34:59] <+JoshWurman> the meso/hook and get dual-Doppler there, and use the Rapid-Scan DOW and
[22:35:12] <+JoshWurman> the UMASS W band to get both ultra-high spatial and temporal observations of
[22:35:27] <+JoshWurman> the tornado vortex itself. XPOL, or another dual-pol radar will sample the hook
[22:35:47] <+JoshWurman> to study microphysical issues, i..e the roles of water, ice, large vs small drops, etc
[22:36:04] <+JoshWurman> in driving the RFD etc. There are a lot of details in the SPO and EDO documents
[22:36:13] <+JoshWurman> which are linked at
www.vortex2.org.
[22:36:18] <+JoshWurman> Now to ROTATE2005:
[22:36:36] <+JoshWurman> We are still struggling to make final plans, and to find enough funding to actually go out.
[22:36:58] <+JoshWurman> This is particularly true this year with the crazy gas prices. DOWs get a whopping 4 mpg, so our
[22:37:16] <+JoshWurman> fleet gets about 1 mph. You can do the $ math for a typical season.
[22:37:37] <+JoshWurman> We are also trying something new this season, providing a real-time DOW radar display, over
[22:37:56] <+JoshWurman> a wireless link to a chase tour company. We hope that this can help fund some of our activities
[22:38:02] <+JoshWurman> in coming seasons.
[22:38:03] <+JoshWurman> end
[22:38:07] <@GeorgeT> thanks for the link to vortex2.org
[22:38:10] <@Chief`Skyreader> (I could fix the site... Chief is available)
[22:38:14] <@GeorgeT> ok, last question...........
[22:38:17] <@GeorgeT> <LauraD> what inspired josh to chase storms?
[22:38:42] <+JoshWurman> I grew up in PA, so not much in the way of chasing there. However, when I moved
[22:39:07] <+JoshWurman> to Boulder in the early 90's, I did some recreational chasing. I became interested in chasing scientifically when
[22:39:30] <+JoshWurman> I read some of the papers by Howie Bluestein and collaborators. Howie really pioneered much of
[22:39:54] <+JoshWurman> scientific chasing. But, I thought that we could have a real revolution with much more ambitious radars.
[22:40:17] <+JoshWurman> Basically they had the "right idea but the wrong toys". So, against much advice, we set out
[22:40:40] <+JoshWurman> to build ambitious radars, with big dishes and powerful transmitters, and fast scanning, basically
[22:41:06] <+JoshWurman> a very non-compromsing radar, but on a truck. Well, that's a long answer. end.
[22:41:29] <@Chief`Skyreader> Do you park across the road like Howie?
[22:41:39] <@Chief`Skyreader> oh I kid HB!
[22:41:52] GeorgeT sets mode: -m
[22:42:05] <+JoshWurman> I don't want to get into criticising particular actions especially if I wasn't there to see it myself.
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[22:42:15] <@GeorgeT> OK, the room is now free to speak at will
[22:42:28] <+JoshWurman> We try to park off the roads as much as possible, but we have done "grey" things on occassion. The key
[22:42:34] <FrankM> how many miles do you typically do a year with the DOWs?
[22:42:36] <@Caleb> Thank you very much for your time, Dr. Wurman; very interesting
[22:42:42] <@GeorgeT> let's remember we have special guests so let's be courteous and well mannered (please)
[22:42:44] <+JoshWurman> is to be reasonable. Blocking a road is not reasonable. Partialy blocking a back dirt road for a little
[22:42:58] <LauraD> Thank you Josh for coming in to chat with us about your research. I wish you the best of luck in your future studies. And you are forgiven, for coming in a little later than scheduled
[22:43:18] <+JoshWurman> while, and moving if a rare vehicle comes along is a different matter. Reasonableness. end
[22:43:25] <tstorm> Thank you for all your research Dr. Wurman. It intrigues me everytime I read up on what you are studying and analyzing.
[22:43:25] <rdewey> The discussion was well worth the wait! Thanks!
[22:43:29] <ef> thank you for answering my questions Josh
[22:43:32] <+JoshWurman> We travel about 10k miles/year doing tornado work, typically.
[22:43:40] <@Chief`Skyreader> Oh I joke Dr W... see all these guys gave him hell for doing it a couple times.,,, I saw him on Happy day... screamed up in black non-chase looking saturn coupe and yelled, "You all are crazy!!" He looked up and recognized me and laughed... I easily drove around him and left the bewildered faces on his students...
[22:43:40] <DougM> Hey Josh, just outta curiousity, I join the convo late...what was the first tornado you've seen?
[22:43:42] <@GeorgeT> 10k miles
[22:43:43] <@GeorgeT> wow
[22:43:48] <NightHawk> wow, Dr Wurman, thanks for taking the time and answering our questions
[22:44:27] <FrankM> yeah... thank you Dr. Wurman
[22:44:30] <+JoshWurman> The first tornado I saw was in Colorado in 1992, just from a car, no DOWs yet.
[22:44:43] <@Chief`Skyreader> could you get Nat Geo to ride along for show and fund some?
[22:44:44] <DougM> thank you for joining us, Mr. Wurman
[22:44:48] <@Chief`Skyreader> TWC or?
[22:44:51] <@GeorgeT> BTW, Dr. John Scala will be here on March 31st at 8 PM Central.....he will be discussing the F-Scale, building construction and warning leadtimes
[22:44:58] <@GeorgeT> everyone is invited back for that one
[22:45:06] <DougM> thank you George
[22:45:09] <@Chief`Skyreader> cool gt...
[22:45:15] <+JoshWurman> We have just published the first actual comparison of measured winds and F-scale damage.
[22:45:33] <+JoshWurman> Amazingly the wind portion of the F-scale is, except for this recent analysis, completely
[22:45:39] <FrankM> due tell us all Dr. Wurman...
[22:45:46] <FrankM> do*
[22:45:55] <DougM> I will definitely be reviewing the conversation i missed...thank you for chatting with us Mr. Wurman
[22:46:03] <+JoshWurman> uncalibrated. The article is Wurman and Alexander in the Jan 2005 MWR.
[22:46:22] <ef> Monthly Weather Review
[22:46:28] <+JoshWurman> The key is that not only are the numerical values of wind in the F-scale uncalibrated, but the basic
[22:46:37] <@Chief`Skyreader> what if there are discrepencies seen!??
[22:46:46] <@Chief`Skyreader>
[22:46:52] <+JoshWurman> underlying assumption that peak gusts cause damae is untested. Who says that damage = f(gust) and that the duration
[22:47:15] <+JoshWurman> of winds over a certain level is not more important (Jarrell? Any hurricane?).
[22:47:41] <+JoshWurman> So, we have presented, in the paper, alternatives like f(duration above threshold)
[22:47:58] <+JoshWurman> f(changing directionality), f( some function of debris loading since it is probably the
[22:48:15] <+JoshWurman> debris that breaches the envelope of buildings and starts the collapses). end
[22:48:21] <@Chief`Skyreader> f( gust * (bumper of ford * vel of bumper**2) * duration on target )
[22:48:23] <@Chief`Skyreader>
[22:48:41] <@Chief`Skyreader> the scrubbing bubbles.... looks great JoshWurman...
[22:48:45] <SA> Like the infamous "roof lifting video" from May 12 near Attica...
[22:48:54] <+JoshWurman> Well, sure. It is likely that damage potential might be something like
[22:49:13] <+JoshWurman> V**3 since the speed and amount and size of debris increases dramatically as
[22:49:14] <SA> To my eye, it appears as if an inflow gust is what lifts the roof off the house frame, not the actual tornado circulation
[22:49:14] <@Chief`Skyreader> ya that might had some missle hurt the supports but it looked like pure lift shane
[22:49:26] <+JoshWurman> windspeed gets higher.. end
[22:49:39] <Mike_H> torque factor must be important too
[22:49:48] <kurt> ?join #stormchase2
[22:49:52] <kurt> oops sorry
[22:49:57] <FrankM> lol
[22:50:03] <@Chief`Skyreader> yes shane... concur... outside debris... jeeez... do we have a name for the ring of crap flying around? bebris skirt?
[22:50:07] <+JoshWurman> As a case in point, the DOW was in extremely high winds north of Geary this past May, bu the
[22:50:09] <@Chief`Skyreader> brain fart
[22:50:14] <ef> with tornadoes, what f-scale is usually associated with vehicles going airborbe
[22:50:25] <+JoshWurman> areas was virtually devoid of sources of debris and we had little damage. My house in
[22:50:34] <ef> airborne
[22:50:42] <ef> cannot spell
[22:50:47] <+JoshWurman> Boulder has ~100 mph gusts at least once per year, but we've never had F1 damage
[22:50:57] <SA> Very interesting
[22:50:59] <+JoshWurman> since there is virtually no debris.
[22:51:10] <+JoshWurman> end
[22:51:15] <Mike_H> tornadic 100mph has torque
[22:51:23] <LauraD> Josh have you ever been to Canada to chase storms?
[22:51:26] <@Chief`Skyreader> and that's it's a dynamic impact... the structure does not have time to 'brace' itself... a steadily increasing straight line wind and it would lean and stress up... a rapid hit or change in direction and the forces become dynamic... the building is in motion when it hits its stress points...
[22:51:49] <+JoshWurman> No, but we've been there to chase a fire. The fire was cancelled, but we caught an unplanned wildfire
[22:52:05] <@Chief`Skyreader> fire whilries?
[22:52:06] <+JoshWurman> in Montana. We've also been to Alaska for aviation weather studies.
[22:52:08] <@Chief`Skyreader> rl
[22:52:23] <@Chief`Skyreader> any plane wake vorticies?
[22:52:30] <+JoshWurman> My belief is that most engineering studies of wind loads take only static pressure forces
[22:52:48] <@Chief`Skyreader> yes... boo static.... 'stuff' moves...
[22:52:49] <+JoshWurman> into account, so duration of gust does not matter. But, as anyone who has seen a hurricane video
[22:53:17] <+JoshWurman> knows, the roof flaps around a while, then gets blown off. Clearly duration of wind can matter.
[22:53:24] <+JoshWurman> end
[22:54:04] <@Chief`Skyreader> as can a slow tornado... could have F3 winds but do F4 damage because of "time on target"?
[22:54:38] <ef> will there ever be a remote controlled dow to drive into a tornado, just a little humor
[22:54:46] <+JoshWurman> Sure, I would imagine that a slow "F3" tornado might do "F4" damage. Of course, a fast moving tornado
[22:55:19] <@Chief`Skyreader> (I can help josh with gas money... DOW Tours!
Get one old van for $10,000 and pack in 4 paying at $2k per... there's 8k per week...)
[22:55:21] <+JoshWurman> gets a bonus "F" on the southern side just due to its motion. So maybe it is a wash. But, we just don't
[22:55:29] <+JoshWurman> know.
[22:55:45] <@GeorgeT> LOL nEAL
[22:56:00] <@Chief`Skyreader> more dows on more storms to become case studies, no?
[22:56:45] <+JoshWurman> We have been going out with project ROTATE nearly every year in order to get more cases. The key is to not just have
[22:56:57] <ef> how much does one of the dows cost to build
[22:57:12] <+JoshWurman> a handful of cases, but have the ~100 in order to be able to study clases of tornadoes, geneses, etc.
[22:57:41] <+JoshWurman> DOWs cost about $500,000 depending on the specs. The Rapid-Scan DOW costs about $1M.
[22:58:04] <@Chief`Skyreader> (first week pays for van, 2nd pays for my 2 months as Nav... 3rd pays for GeorgeT's driving van... so 6 weeks at 7k (1k less for gas/rooms) is 42k for the season...
[22:58:15] <@Chief`Skyreader> oh jeeez.... ouuch...
[22:58:21] <@Chief`Skyreader> n/m
[22:58:23] <@Chief`Skyreader>
[22:58:29] <@Chief`Skyreader> you need Bill Gates!
[22:58:34] <@GeorgeT> lol
[22:59:05] <@Chief`Skyreader> oh! that British guy that owns airlines and such... ballons around etc...
[22:59:11] <@Chief`Skyreader> +o
[22:59:14] <DougM> Richard Branson
[22:59:17] <+JoshWurman> We're working with Todd Thorn of Storm Chase Adventure Tours this year, but may work
[22:59:19] <@Chief`Skyreader> bingo
[22:59:43] <+JoshWurman> with an additional company in 2006. The key is whether there is enough interest from customers to make
[23:00:04] <@Chief`Skyreader> How about old russian phased array... I can get you a 5m panel for $20k and some Coors Beer..
[23:00:06] <+JoshWurman> it economically viable. They do get a different experience by seeing the scientific data, etc. But there
[23:00:16] <+JoshWurman> is an additional cost.
[23:00:35] <tstorm> that is a tour I would be interested in!
[23:00:42] <+JoshWurman> Using converted phased arrays is tempting. But, the conversion to a weather radar probably costs more than the cost of the new Rapid-Scan DOW.
[23:00:43] <ef> when inside the dow, looking at the radar data coming in, do you actually get out of the truck and view the tornado visually yourself
[23:00:47] <@Chief`Skyreader> do you GPS correct the velocities?
[23:01:15] Joins: Guest92 (
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[23:01:16] <+JoshWurman> I rarely get out of the truck. I'm often amazed by the video. During multiple-DOW missions I am completely absorbed
[23:01:20] * Matt_T is away: away
[23:01:26] <@GeorgeT> hi Guest92
[23:01:40] <+JoshWurman> in trying to keep the trucks coordinated and triangulated on the storm. The minute we're deployed, I'm trying to figure out
[23:02:02] <+JoshWurman> the next deployment location, when we have to move (in a coordinated fashion), and the route. Frankly, it is not
[23:02:23] <+JoshWurman> much fun. When we have radar breakdowns and we only have one radar I'm free to do more conventinal intercepts,
[23:02:48] <+JoshWurman> i.e. drive at the tornado and it is much more fun, even relaxing.
[23:02:50] <Guest92> Cant change my nick
[23:02:52] <@GeorgeT> I bet such an operation involves quite a few people
[23:02:55] <Mike_H> what hail size is considered too big for the dows
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[23:03:03] <@GeorgeT> Guest 92, type /nick JohnDoe
[23:03:04] Guest92 (
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[23:03:07] <SA> hey Sheila
[23:03:11] <+JoshWurman> In answer to the other question, we do not now, but will soon, correct our data using gps.
[23:03:11] <Mike_H> or does it matter
[23:03:12] <@GeorgeT> hi Sheila
[23:03:13] <SA> welcome Tornx
[23:03:14] <Mike_H> sheila
[23:03:16] <Tornx> Oh
[23:03:19] <Tornx> LOL
[23:03:28] <Sheila> hey all
[23:03:30] <+JoshWurman> The biggest hail that the DOWs have experienced is softball, but anything over golfball is too large
[23:03:47] <Tornx> Hey Skyreader
[23:03:49] <+JoshWurman> and we take precations such as pointing our antenna away from it. We go through windshields
[23:04:05] <+JoshWurman> a couple/few times a season..
[23:04:15] <Mike_H> nice, lol
[23:04:33] <+JoshWurman> In answer the other question: We use 3 people per vehicle. So last year our crew was 12.
[23:04:51] <+JoshWurman> It all depends on how many trucks we take out. We may have a smaller experiment this year due to $.
[23:05:16] <ef> i paid 225 a gallon for gas today
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[23:05:32] <tstorm> 1.89 here
[23:05:35] <NightHawk> hey Bob
[23:05:43] <kurt> tstorm were you at
[23:05:45] <@GeorgeT> We could always write Congress on behalf of you guys and request more $$$
[23:05:45] <@GeorgeT>
[23:05:50] <tstorm> houston area
[23:05:50] <@Chief`Skyreader> hay bob... JoshWurman is here... we;re in casual chat though... feel free to ask a question
[23:05:51] <ef> will there be any improvements in the DOWS
[23:05:51] <@GeorgeT> Hi Bob
[23:05:53] <Tornx> $2.25? sic!
[23:05:56] <ef> in technology
[23:06:07] <kurt> its 208 at some stations but i saw it at 2.25 tonight never have i seen it that high here
[23:06:16] <DougM> Hey Josh, don't worry, I'm in pre-law Poltical Science, if I ever become a congressman, I'll give you all the funding you need
[23:06:16] <+JoshWurman> We are always working on improvements. The Rapid-Scan 6 beam DOW is a qualitative improvement.
[23:06:16] <LauraD> Hey, Bob.
[23:06:24] <ScudStudBob> Top O' the Evenin' and Happy St Patty's to ye
[23:06:30] <NightHawk> ty bob
[23:06:31] <@Chief`Skyreader> how long for a scan?
[23:06:36] <+JoshWurman> We are working to improve the quality of the data we collect while moving. We are working
[23:06:53] <+JoshWurman> on the wireless remote real-time display that I mentioned a while back. etc.
[23:07:10] <@Chief`Skyreader> how long for a scan? ie, how many frames can I see in a loop?
as apposed to 1/3 or 6 min..
[23:07:12] <+JoshWurman> We always make minor improvements. Last year we got a Wxworx for example.
[23:07:34] <+JoshWurman> We take about 4-5 sec per sweep, and about 12 sweeps per volume, so we update
[23:07:42] <Tornx> How you like the Wxworx?
[23:07:48] <Tornx> I just bought one
[23:07:59] <+JoshWurman> at about 50-60 sec intervals. Thats' better than the 88D's, but not nearly as good as the rapid-scan at 5 sec per volume.
[23:08:31] * @Chief`Skyreader could write RasGPS for DOW... Include topographical data to allow high? observation points denoted along path...
Shading of visible ground at 10'?
[23:08:32] <+JoshWurman> While it has obvious and frustrating limitations, I liked the wxworx a lot. It is reasonably priced and
[23:08:32] <@Chief`Skyreader>
[23:09:16] <+JoshWurman> provides pretty good data. I'm sure that minor improvements will be made in coming years.
[23:09:35] <Tornx> Great
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[23:09:41] <@Chief`Skyreader> 5 sec... wow... nice loops... cool...
[23:09:47] <+JoshWurman> Erik Rasmussen and I have proposed a pre-VORTEX2 project to put the remote DOW display on a GIS map along with
[23:10:07] <NightHawk> Dr Wurman, thank you for answering my phased-array radar question earlier...I operate a military phased-array radar(AN/TPS-75)...I was curious in how phased-array systems were incorporated into weather research
[23:10:24] <+JoshWurman> the locations of other vehicles, forecasts, etc. in preparation for having ~40 vehicles out in VORTEX2.
[23:10:36] Parts: ckuster (
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[23:11:01] <+JoshWurman> Nighthawk: as you know, thee spy1 phased array system is being converted to weather use in norman. also, a group in california
[23:11:09] * @Chief`Skyreader note to Homeland Def... NightHawk disclosed use of AN/TPS-75 against regs AF4124-14233934B- sub paragraph C section 34.2
[23:11:13] <NightHawk> lol
[23:11:19] <@GeorgeT> lol
[23:11:33] <+JoshWurman> is working to convert a mobile system for weather work. the problem with these systems is mainly cost (and beamwidth secondarily).
[23:11:51] <NightHawk> I would understand, with the costs
[23:11:56] <NightHawk> it isn't cheap
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[23:12:24] <+JoshWurman> The beamwidth of the spy1 radar means that high res data is only collected within, say, 30 km
[23:12:32] <NightHawk> wow
[23:12:45] <+JoshWurman> of the radar. (that's true of dows and other systems too.) But that means that a 88D
[23:13:02] <+JoshWurman> like spacing would mean only high res data in 2-3% of the domain. Basically
[23:13:15] <+JoshWurman> the benefits of phased array are only achieved if you're really really close to the
[23:13:27] <@GeorgeT> Hopefully we'll get some nice storms soon (over unpopulated areas) in which to study
[23:13:28] <+JoshWurman> weather, which is impossible for the converted SPY1.
[23:13:33] <NightHawk> ah
[23:13:53] <ef> NWS, should add more NEXRAD sites to fill the gaps, will that ever happen
[23:14:05] <@GeorgeT> that would be nice EF
[23:14:07] <NightHawk> ty, Josh
[23:14:13] Quits: SA (
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[23:14:13] <@GeorgeT> There certainly are a few gaps in coverage
[23:14:28] Quits: Fabian (
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[23:14:31] <+JoshWurman> The NWS would have to add 500-1000 sites to fill in the gaps. CASA type radars don't work either because, to keep
[23:14:35] <@Chief`Skyreader> Oh ya... RasGPS will have what I call MOBs.. Moveable Object Blocks... One of which could be auto-created as each vehicle comes on-line... These MOBs can have realtime updated velocities, and allow inter vehicle messaging... MOBs may also be a meso or TVS... assigned by operator... or fed of data, but tougher... also RasGPS will have a shortcast feature that extraploates all MOBs out in time 5, 10, 15 min, etc...
[23:14:39] <@Chief`Skyreader> yep 512...
[23:14:41] <@Chief`Skyreader>
[23:14:41] <+JoshWurman> costs down, they have large beamwidths.
[23:15:03] <@GeorgeT> that's too bad
[23:15:08] <ef> what does a new NEXRAD system cost these days
[23:15:35] <Tornx> That remote DOW on GIS pre-vortex2 display you mentioned a min ago- will that be public accessible?
[23:15:43] <@Chief`Skyreader> 4 billion EF...
[23:15:48] <+JoshWurman> I don't now the cost of a modern 88d, probably $10m or so.
[23:16:13] <@GeorgeT> yikes
[23:16:17] <+JoshWurman> The remote display that we're providing to the tour company will not be available since we're
[23:16:31] <@GeorgeT> guess that means we won't be able to get one for our front lawn, EF!
[23:16:44] <ef> lol
[23:16:44] <+JoshWurman> trying to sell the service to fund our scientific experiment. The VORTEX2 display? I don't know.
[23:17:21] <Tornx> Which Tour?
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[23:17:59] <@Chief`Skyreader> Pepsi! Phased arrays Everywhere Possibily Saving lIves...
[23:18:00] <@GeorgeT> wb Nick
[23:18:01] <+JoshWurman> Storm Chaser Adventure Tours this year. Probably them and another company (anyone interested, please contact us) in 2006.
[23:18:38] <NickG> It was that "ghost" thing again with NG...LOL. Ty George.
[23:18:44] <ef> TRADD will volunteer, inside joke
[23:18:49] <@GeorgeT> hehe
[23:18:59] <@Chief`Skyreader> sell feed to TWC?
[23:19:00] <Tornx> LOL
[23:19:22] <+JoshWurman> We've asked TWC. It would seem a natural. No interest to date.
[23:19:25] <Tornx> Yea seems TWC would pay $$
[23:20:08] <@Chief`Skyreader> oh! ummm high def tv.... they'll pay $$$ for high def vid of a fish tank for god's sake...
[23:20:13] <DougM> Josh, has the data from VORTEX I been intrepreted (Tornado Video Classics by Tom Grazulius said it would take 10 years to intrepret the data) and if the VORTEX II project is seperate from the first project or a supplement?
[23:20:13] <ScudStudBob> It might interrupt Storm Stories
[23:20:17] <+JoshWurman> I would think that cutting live to a real-time DOW display of a tornado, being able to say precisely how intense, growing, weakening, etc would be exciting for TWC, but they have not bitten.
[23:20:25] Quits: JayM (
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[23:20:37] <@GeorgeT> I'm sure Dr. Forbes could make good use of it
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[23:20:53] <+JoshWurman> Much from VORTEX1 has been interpreted, as has post-V1 data from ROTATE. However much remains to be done, hence
[23:20:57] <@GeorgeT> would be better than hearing a gardening report from P. Allen Smith
[23:20:59] <@GeorgeT>
[23:21:03] <@Caleb> Indeed
[23:21:19] <DougM> Josh, could you describe the "work that needs to be done"?
[23:21:21] <@Chief`Skyreader> Need any Software Engineers to crunch data?
[23:21:24] <+JoshWurman> our current analyses projects. The V2 SPO talks a lot about the current state of the art, what has been learned from V1, etc.
[23:21:53] <+JoshWurman> Well, at a fundimental level, we still don't know why most rotating thunderstorms don't produce tornadoes but some do. And
[23:22:37] <+JoshWurman> we don't really know when the producers will produce. And, we don't know if the tornadoes will be weak or intense, long or short lived, cyclic or singular. That's
[23:22:57] <DougM> okay...out of all the theories of why some supercells produce tornadoes and some don't...which intrigues you the most?
[23:22:59] <+JoshWurman> a lot not to know.
[23:23:41] <+JoshWurman> Well, I like simple over complex and think it really just comes down to low level temperature, so
[23:23:52] <@Chief`Skyreader> Could you get a value of the theta-e around with radar??? that would be helpful...
[23:24:05] <DougM> occam's razor...i see, hehe
thanks Josh
[23:24:20] <+JoshWurman> the question is which structures keep warm air near the tornadoes and which don't. There's probably a lot
[23:24:23] <ef> Have you sample many LP's supercells with the DOWS
[23:24:55] <+JoshWurman> of subteties, but that's basically it. We can measure theta-e near the tornado a the DOW trucks. In V2 we'll use
[23:25:19] <+JoshWurman> a lot of mobile mesonet cars and, we hope, a fleet of UAV's which can measure critical data above the surface.
[23:25:51] <+JoshWurman> Finally, with really high quality dual-Doppler data, one can calculate 3D fields of temperature (really pertubation buoyancy) using
[23:25:54] <@GeorgeT> The UAV's sound really interesting
[23:25:55] <+JoshWurman> just radar data.
[23:26:01] <@GeorgeT> Erik mentioned those
[23:26:09] <@Chief`Skyreader> cool
[23:26:13] <@Chief`Skyreader> on 3D fields
[23:26:15] <DougM> Who will be supplying the Unmanned Aerial Vehicles for V2 if it comes to fruition?
[23:26:25] <+JoshWurman> The UAV's are one of the major exciting new technologies to emerge post V1. That and DOWs
[23:26:39] <+JoshWurman> are what will be the qualitative differenc between V1 and V2.
[23:26:55] <ef> isn;t university of colorado working on the uav's
[23:26:56] <@Chief`Skyreader> UAV's 'almost' made IHOP folks... they came close to test runs during IHOP I believe...
[23:27:12] <+JoshWurman> CU is developing instrumented inexpensive UAVs. The trick is to keep 'em cheap. The military
[23:27:35] <+JoshWurman> has UAV's for a price, just like they have phased array radars, but at ~1M$ a pop, we won't see
[23:27:41] <+JoshWurman> them near tornadoes anytime soon.
[23:27:48] <DougM> Geukes, I know that University of Colorado was working on a UAV for *pre*-tornadic-supercell development, my soon-to-be-uncle was working on it and he graduated top of his class
[23:27:58] <NightHawk> ah, UAVs
[23:28:15] <NightHawk> that really interested me when Erik mentioned that
[23:28:16] <+JoshWurman> That's probably the same CU project, the group is RECUV, I believe. Erik is working
[23:28:32] <+JoshWurman> closely with them and the pre-VORTEX2 proposal that I discussed integrated the
[23:28:35] <NightHawk> I was figuring that he was contracting use of Predators
[23:28:37] <NightHawk> lol
[23:28:47] <+JoshWurman> UAV data, DOW data, and a real-time display all together.
[23:28:51] <DougM> my soon-to-be-uncle is now going to Stanford, paid for by Lockheed Martin
[23:28:55] <@Chief`Skyreader> pilotless A10;s epoxy...
[23:29:20] <NightHawk> pilotless, eh?
[23:29:22] <@Chief`Skyreader> ;
[23:29:22] <NightHawk> lol
[23:29:25] <@Chief`Skyreader>
[23:29:30] <NightHawk> someday, perhaps
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[23:30:17] <+JoshWurman> Well, it is 2130 here in CO, so I'm signing off. Thank you all for a very interesting conversation. I apoligize again for my late start. I was confused about the timezone.
[23:30:39] <@Chief`Skyreader> quite all right Dr Wurman...
[23:30:44] <tstorm> thank you for your time and answering all our questions!
[23:30:48] <LauraD> Thank you Josh for coming in tonight to discuss your research with us. We very much appreciate your time and effort. Thank you again.
[23:30:52] <ef> thanks for chatting with us josh
[23:30:52] <DougM> Thank you for your presence Dr. Wurman
[23:30:56] <NightHawk> thanks a lot for taking your time to answer our questions, Dr Wurman
[23:30:57] <@Caleb> Thank you very much again, Dr. Wurman
[23:31:00] <kanani> thanks Dr.Wurman
[23:31:00] <@Chief`Skyreader> thanks for joining us and giving us the scope...
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