Calderon Posted May 29, 2011 Share Posted May 29, 2011 This may be of interest: http://grubshanks.xa...tem/?ref=recent pretty safe bet this beast is an EF-5 Link to comment Share on other sites More sharing options...
AtticaFanatica Posted May 31, 2011 Share Posted May 31, 2011 Goldsby and Chickasha both high-end EF-4's, El Reno still being looked at. Link to comment Share on other sites More sharing options...
natecast Posted May 31, 2011 Share Posted May 31, 2011 Goldsby and Chickasha both high-end EF-4's, El Reno still being looked at. Nothing's a given, but I'm pretty sure the El Reno-Piedmont tornado is going to be upgraded to EF-5. Could they possibly just be working out the wind speed estimates? Two other high-end EF-4's during the same outbreak is pretty darned impressive. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted May 31, 2011 Share Posted May 31, 2011 Nothing's a given, but I'm pretty sure the El Reno-Piedmont tornado is going to be upgraded to EF-5. Could they possibly just be working out the wind speed estimates? Two other high-end EF-4's during the same outbreak is pretty darned impressive. I know there has been spirited debate about the rating of all these tornadoes for quite a while now. There is additional information about the Piedmont tornado, maybe that is prolonging a final decision. Link to comment Share on other sites More sharing options...
thewxmann Posted May 31, 2011 Share Posted May 31, 2011 I dunno, if they're taking this long to decide on a rating, it's probably not gonna be an EF5. Perhaps many things favor an EF5 rating but the construction of the homes would preclude one (i.e. the usual 'rural homes are not as well constructed'). But borderline cases would get the lower rating. Link to comment Share on other sites More sharing options...
Amped Posted June 1, 2011 Share Posted June 1, 2011 I dunno, if they're taking this long to decide on a rating, it's probably not gonna be an EF5. Perhaps many things favor an EF5 rating but the construction of the homes would preclude one (i.e. the usual 'rural homes are not as well constructed'). But borderline cases would get the lower rating. They gave Tuscolusa a EF4 190MPH for that reason, so they might as well be consistent and do it here too. Link to comment Share on other sites More sharing options...
natecast Posted June 1, 2011 Share Posted June 1, 2011 They gave Tuscolusa a EF4 190MPH for that reason, so they might as well be consistent and do it here too. One would think it would be difficult to compare tornadoes that occur in an urban setting as opposed to a rural setting. It seems like it would be more difficult for a tornado to produce EF-5 damage when homes are clustered together in a neighborhood and debris is piling up and falling every which direction. Which makes the Joplin tornado even more amazing. Link to comment Share on other sites More sharing options...
thewxmann Posted June 1, 2011 Share Posted June 1, 2011 Check out this montage on Facebook. This was a home in Piedmont that appears to have been swept clean, and the home was bolted to the foundation. The pictures are also a great advertisement for safe rooms. http://www.facebook....4178.1379126705 One would think it would be difficult to compare tornadoes that occur in an urban setting as opposed to a rural setting. It seems like it would be more difficult for a tornado to produce EF-5 damage when homes are clustered together in a neighborhood and debris is piling up and falling every which direction. Which makes the Joplin tornado even more amazing. FYI, I am unable to view the montage. It's actually much easier to produce an EF5 rating in an urban environment. One, debris in a tornado can compromise the structural integrity of buildings, making the winds that much more effective at doing damage; two, there are just that many more damage indicators in an urban setting. For instance, the Home Depot damage made the EF5 rating for the Joplin tornado that much easier to assign. You're not going to see that in rural OK. It's very hard to assign EF5 damage to homes because of different construction standards, etc. And usually, if there's doubt, the EF5 isn't given (just read the Tuscaloosa PNS, almost every paragraph provides some justification as to why EF5 wasn't assigned despite "homes swept clean"). Link to comment Share on other sites More sharing options...
natecast Posted June 1, 2011 Share Posted June 1, 2011 FYI, I am unable to view the montage. It's actually much easier to produce an EF5 rating in an urban environment. One, debris in a tornado can compromise the structural integrity of buildings, making the winds that much more effective at doing damage; two, there are just that many more damage indicators in an urban setting. For instance, the Home Depot damage made the EF5 rating for the Joplin tornado that much easier to assign. You're not going to see that in rural OK. It's very hard to assign EF5 damage to homes because of different construction standards, etc. And usually, if there's doubt, the EF5 isn't given (just read the Tuscaloosa PNS, almost every paragraph provides some justification as to why EF5 wasn't assigned despite "homes swept clean"). Sorry about that link, I forgot the pictures are set on a private setting and you've got to be friends with the poster. Also, my computer won't let me upload the pictures. Oh well. You make good points about the urban versus rural setting for a tornado. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 1, 2011 Share Posted June 1, 2011 El Reno rating will be released this afternoon with explanation. Hearing there is considerable disagreement, but it's looking like EF-4 despite some conflicting information. Link to comment Share on other sites More sharing options...
blackjack123 Posted June 1, 2011 Share Posted June 1, 2011 El Reno rating will be released this afternoon with explanation. Hearing there is considerable disagreement, but it's looking like EF-4 despite some conflicting information. There is so much debate between a high-end EF4 and an EF5 rating that it is almost sickening. There tends to be more scrutiny placed on an EF5 rating versus an EF4. I am not meaning any of this to be negative because there is a lot of debate. I mean you could call the Bridge Creek/Moore/OKC tornado from 1999 a high-end F4 or the Joplin tornado a high-end EF4. The only thing with these two tornadoes that it was only obvious to surveyors that there were structures built well enough to validate an F5/EF5 rating. Like said it is hard for tornadoes that hit only a few structures including a couple well-built homes swept off their foundations in rural areas to get an F5/EF5 rating. They could have very well been deserving of it although. A few of them I can think of would be 11-24-01(Mississippi), 6-23-02, 5-4-03(Girard/Franklin), 6-24-03(Manchester),5-12-04(Harper), 5-22-10(Bowdle)6-17-10(Holmes County, South Dakota), and 6-25-10( near Sibley, Iowa). The high-end F4/EF4 rating for all these tornadoes does seem like a reasonable estimate but I would not say F5/EF5 is impossible. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 1, 2011 Share Posted June 1, 2011 EF5 Link to comment Share on other sites More sharing options...
thewxmann Posted June 1, 2011 Share Posted June 1, 2011 EF5 Change of heart? Link to comment Share on other sites More sharing options...
blackjack123 Posted June 1, 2011 Share Posted June 1, 2011 Change of heart? Sure is. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 1, 2011 Share Posted June 1, 2011 STORM 2... BINGER-EL RENO-PIEDMONT-GUTHRIE PRELIMINARY DATA... EVENT DATE: MAY 24, 2011 EVENT TYPE: TORNADO EF RATING: EF-5 ESTIMATED PEAK WINDS (MPH): GREATER THAN 210 MPH INJURIES/FATALITIES: UNKNOWN/9 EVENT START LOCATION AND TIME: 8 WNW BINGER 3:30 PM CDT EVENT END LOCATION AND TIME: 4 NE GUTHRIE 5:35 PM CDT DAMAGE PATH LENGTH (IN MILES): 75 MILES DAMAGE WIDTH: UNKNOWN NOTE: RATING BASED ON UNIVERSITY OF OKLAHOMA MOBILE DOPPLER RADAR MEASUREMENTS. Link to comment Share on other sites More sharing options...
hm8 Posted June 1, 2011 Share Posted June 1, 2011 NOTE: RATING BASED ON UNIVERSITY OF OKLAHOMA MOBILE DOPPLER RADAR MEASUREMENTS. Interesting...if there was hard radar data I wonder why their would be controversy. Link to comment Share on other sites More sharing options...
thewxmann Posted June 1, 2011 Share Posted June 1, 2011 Doppler radar measured windspeeds became a DI? Anyway, thanks for all the updates Attica... this is definitely kinda new here... Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 1, 2011 Share Posted June 1, 2011 Interesting...if there was hard radar data I wonder why their would be controversy. Radars don't scan scan at the surface, they are tilted in elevation. Link to comment Share on other sites More sharing options...
hm8 Posted June 1, 2011 Share Posted June 1, 2011 Radars don't scan scan at the surface, they are tilted in elevation. right...so why would the rating be based solely on radar data? I guess even though that's all it says the rating was based on their must have been other factors involved... Link to comment Share on other sites More sharing options...
natecast Posted June 1, 2011 Share Posted June 1, 2011 STORM 2... BINGER-EL RENO-PIEDMONT-GUTHRIE PRELIMINARY DATA... EVENT DATE: MAY 24, 2011 EVENT TYPE: TORNADO EF RATING: EF-5 ESTIMATED PEAK WINDS (MPH): GREATER THAN 210 MPH INJURIES/FATALITIES: UNKNOWN/9 EVENT START LOCATION AND TIME: 8 WNW BINGER 3:30 PM CDT EVENT END LOCATION AND TIME: 4 NE GUTHRIE 5:35 PM CDT DAMAGE PATH LENGTH (IN MILES): 75 MILES DAMAGE WIDTH: UNKNOWN NOTE: RATING BASED ON UNIVERSITY OF OKLAHOMA MOBILE DOPPLER RADAR MEASUREMENTS. I agree with the rating from the damage photos I've seen, but why would they put doppler radar measurements as the basis for an EF rating?!?!? Why would they not put damage cases in the description to back up this rating? I'm shocked. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 1, 2011 Share Posted June 1, 2011 Doppler radar measured windspeeds became a DI? Well, now you know what I was being cryptic about and what the debate was about even into this afternoon. Link to comment Share on other sites More sharing options...
huronicane Posted June 1, 2011 Share Posted June 1, 2011 What kind of wind speeds were recorded? I'd assume the 210 is an estimated surface reduction? Link to comment Share on other sites More sharing options...
brettjrob Posted June 2, 2011 Share Posted June 2, 2011 I hear that the mobile radar data indicated that the first tornado from this storm, which crossed US-283 at Lookeba (N of Binger), actually dissipated and that the El Reno-Piedmont tornado subsequently developed somewhere near the Canadian/Caddo Co. line. Interestingly, it appears that the NWS OUN survey has maintained this as all one track. Also, I was quite surprised to see the radar data used as justification for an upgrade in this age of more stringent ratings, when the 1991-04-26 tornado at Red Rock was not upgraded despite mobile radar-indicated 250+ mph winds. (Not sure what the elevation was of that measurement, but I've seen Dr. Bluestein's video and it crosses the road a couple football fields away, so I imagine it was at least as low as the El Reno case). Link to comment Share on other sites More sharing options...
blackjack123 Posted June 2, 2011 Share Posted June 2, 2011 Doppler radar measured windspeeds became a DI? Anyway, thanks for all the updates Attica... this is definitely kinda new here... I am a little surprised myself. Winds are winds. It all depends on the duration of the winds and how it hits the structure to cause certain types of damage to get an EF-rating. The damage photos did look like they were probably borderline EF4/EF5 so maybe that is why they used the wind measurement as a factor to upgrade the tornado to an EF5. Link to comment Share on other sites More sharing options...
radarman Posted June 2, 2011 Share Posted June 2, 2011 I was looking at the winds from the Chickasha tornado and was very impressed. The CASA radar doppler velocity folds at roughly 75 knots. Obviously you'd expect major wraparound when looking at a beast like this, and being so close to the ground, with such violent winds, noise, and debris, unfolding the data can be difficult. Below is a image of folded velocity values (in kts.) Looking for continuity in the values, I believe we may be seeing outbound velocities hit 75kts, and then wrap all the way back to -3kts. If this is correct, we are measuring winds of 147kts (~170 mph) <500m off the ground. You'll certainly see some noise in the velocities, so I am not 100% confident in this measurement, but the continuous values along a few of these radiials suggests they may be correct. I have a few other frames where it's possible the data starts to wrap even further, back into positive territory, but I'm not done with the analysis yet. This would support the EF4 ranking. Although the winds at the ground may not be as high, it's quite likely that the short intervals we are scanning the couplet did not catch the absolute max velocities. Link to comment Share on other sites More sharing options...
natecast Posted June 2, 2011 Share Posted June 2, 2011 NWS Norman has updated the Lookeba to Guthrie tornado track. It gave me chills. It is blatantly obvious that after approaching I-40, that beast had taken a hard right turn. This continued until just beyond El-Reno, when it veered north. After looking at radar loops, I believe the number of storms in the area is what caused the northward jog, as the parent storm and mesocyclone traveresed the path with greatest instability and less interference from other storms. Link to comment Share on other sites More sharing options...
LocoAko Posted June 2, 2011 Share Posted June 2, 2011 NWS Norman has updated the Lookeba to Guthrie tornado track. It gave me chills. It is blatantly obvious that after approaching I-40, that beast had taken a hard right turn. This continued until just beyond El-Reno, when it veered north. After looking at radar loops, I believe the number of storms in the area is what caused the northward jog, as the parent storm and mesocyclone traveresed the path with greatest instability and less interference from other storms. Yeah, it is remarkable how close Moore and Norman came to having a huge problem. Link to comment Share on other sites More sharing options...
tornadotony Posted June 6, 2011 Share Posted June 6, 2011 Lookeba tornado is split off from the EF5 track as a separate EF3 track now. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 6, 2011 Share Posted June 6, 2011 Lookeba tornado is split off from the EF5 track as a separate EF3 track now. Yeah, that's the right call. Link to comment Share on other sites More sharing options...
Arnold214 Posted June 6, 2011 Share Posted June 6, 2011 I was looking at the winds from the Chickasha tornado and was very impressed. The CASA radar doppler velocity folds at roughly 75 knots. Obviously you'd expect major wraparound when looking at a beast like this, and being so close to the ground, with such violent winds, noise, and debris, unfolding the data can be difficult. Below is a image of folded velocity values (in kts.) Looking for continuity in the values, I believe we may be seeing outbound velocities hit 75kts, and then wrap all the way back to -3kts. If this is correct, we are measuring winds of 147kts (~170 mph) <500m off the ground. You'll certainly see some noise in the velocities, so I am not 100% confident in this measurement, but the continuous values along a few of these radiials suggests they may be correct. I have a few other frames where it's possible the data starts to wrap even further, back into positive territory, but I'm not done with the analysis yet. This would support the EF4 ranking. Although the winds at the ground may not be as high, it's quite likely that the short intervals we are scanning the couplet did not catch the absolute max velocities. Do you guys have to unfold all that data manually or do you have some sort of unfolding program that does most of it for you? I'd say if I were working on a paper or presentation that used raw CASA or DOW data it would take a heck of a long time to get everything unfolded properly. Link to comment Share on other sites More sharing options...
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