AtticaFanatica Posted May 3, 2014 Share Posted May 3, 2014 I think there'd be a lot less argument if the EF scale was a bit more open ended with it's final rating. Currently you see reports like 'the tornado has been rated EF4 with winds between 180mph and 190mph' which is quite specific. If it was phrased such that the tornado produced upto EF4 damage with wind speeds of at least 180mph, it leaves open the fact that it was likely stronger at some point which is statistically likely as a tornado generally only spends a small part of it's life cycle impacting buildings. People might then be more happy to accept the ratings and we'd get less of these ridiculous posts that clogged up this thread when the rating was announced! Affixing an upper end to the speed based on observed damage in just a small part of the tornado life cycle seems a little odd to me. Agreed. Stop pretending we have the type of accuracy conveyed in the ratings. We do not. Link to comment Share on other sites More sharing options...
blackjack123 Posted May 3, 2014 Share Posted May 3, 2014 Sorry about the rant. I have tended to be just as impressed if not more impressed by tornadoes that were rated high-end EF4 than some of the tornadoes that were rated EF5. I wish they would use other factors besides home and building damage. Like for instance the tree debarking, scouring of the ground, wind rowing, debris granulation, and mangling of vehicles have been even more impressive in high-end EF4's than even some of the more recent events rated EF5. I was just as impressed with this in Vilonia if not more impressed than even the Moore EF5 tornado from last year. The high-end EF4 rating is defenitely nothing to sneeze but there seemed to be other factors besides home/building damage that could have warranted an EF5 rating. I tend to wonder if a DOW would have helped had it been readily available. Link to comment Share on other sites More sharing options...
TropicalAnalystwx13 Posted May 3, 2014 Share Posted May 3, 2014 Sorry about the rant. I have tended to be just as impressed if not more impressed by tornadoes that were rated high-end EF4 than some of the tornadoes that were rated EF5. I wish they would use other factors besides home and building damage. Like for instance the tree debarking, scouring of the ground, wind rowing, debris granulation, and mangling of vehicles have been even more impressive in high-end EF4's than even some of the more recent events rated EF5. I was just as impressed with this in Vilonia if not more impressed than even the Moore EF5 tornado from last year. The high-end EF4 rating is defenitely nothing to sneeze but there seemed to be other factors besides home/building damage that could have warranted an EF5 rating. I tend to wonder if a DOW would have helped had it been readily available. It all has to be used in context. Tornadoes of EF3 intensity and higher are capable of debarking trees, but if you see debarking near a home with its foundation swept clean (*and the home was well-constructed* see below), that would give more confidence in an EF5 rating. Ground scouring and granulated debris can occur in high-end EF4 tornadoes. The image of the neighborhood in Vilonia was high-end EF4 damage. Despite foundations swept clean and what appears to be some ground scouring near the homes, the structures lacked anchor bolts and instead used cut nails. EF4 tornadoes are able to sweep homes with this construction away. Link to comment Share on other sites More sharing options...
FSMweather Posted May 3, 2014 Share Posted May 3, 2014 Interesting read about a tornado-related death that happened while a lady was in a tornado shelter during the Mayflower/Vilonia tornado. http://5newsonline.com/2014/05/02/above-ground-shelter-requirements/ Link to comment Share on other sites More sharing options...
andyhb Posted May 3, 2014 Author Share Posted May 3, 2014 According to various sources, including Harold Brooks, the door itself wasn't properly engineered. Link to comment Share on other sites More sharing options...
Disc Posted May 3, 2014 Share Posted May 3, 2014 Anyone have the damage assessment for the Lincoln County, TN tornado or have I overlooked it? Link to comment Share on other sites More sharing options...
andyhb Posted May 3, 2014 Author Share Posted May 3, 2014 Currently high end EF3. http://www.srh.noaa.gov/hun/?n=hunsur_2014-04-28#fortpayne Link to comment Share on other sites More sharing options...
JoMo Posted May 3, 2014 Share Posted May 3, 2014 According to various sources, including Harold Brooks, the door itself wasn't properly engineered. Do you have more information on this? I only found two other articles and they didn't provide a lot of details other than it looks like the shelter sustained an impact between the 'deadbolt' and the doorhandle. It also looks like the door was a 'swing in' type of construction. Link to comment Share on other sites More sharing options...
andyhb Posted May 3, 2014 Author Share Posted May 3, 2014 Where I got the Dr. Brooks reference, since I'm assuming this is him commenting here. http://www.koco.com/weather/experts-investigate-safe-room-tornado-death/25775010 Link to comment Share on other sites More sharing options...
JoMo Posted May 4, 2014 Share Posted May 4, 2014 Where I got the Dr. Brooks reference, since I'm assuming this is him commenting here. http://www.koco.com/weather/experts-investigate-safe-room-tornado-death/25775010 Thanks. Well, that would make sense if it was not built to any specifications. Link to comment Share on other sites More sharing options...
Arnold214 Posted May 4, 2014 Share Posted May 4, 2014 http://www.srh.noaa.gov/lzk/?n=anchor0514.htm Link to comment Share on other sites More sharing options...
huronicane Posted May 4, 2014 Share Posted May 4, 2014 http://www.srh.noaa.gov/lzk/?n=anchor0514.htm That, and the other links on that page, are great information. Link to comment Share on other sites More sharing options...
Ground Scouring Posted May 4, 2014 Share Posted May 4, 2014 http://www.srh.noaa.gov/lzk/?n=anchor0514.htm The only problem with the article is 1) that it says most (not ALL!) homes that were leveled lacked anchor bolts, implying that some did; and 2) that at least one home on E Wicker Street, just northeast of downtown Vilonia, was apparently anchor-bolted and yet completely swept away, with substantial ground scouring and removal of vegetation next to the foundation. Maybe the surveyors missed the signs of anchorage? Needless to say, the EF4 rating looks much more questionable than it did a week ago. Link to comment Share on other sites More sharing options...
thewxmann Posted May 4, 2014 Share Posted May 4, 2014 The only problem with the article is 1) that it says most (not ALL!) homes that were leveled lacked anchor bolts, implying that some did; and 2) that at least one home on E Wicker Street, just northeast of downtown Vilonia, was apparently anchor-bolted and yet completely swept away, with substantial ground scouring and removal of vegetation next to the foundation. Maybe the surveyors missed the signs of anchorage? Needless to say, the EF4 rating looks much more questionable than it did a week ago. While some homes were anchor-bolted I bet the spacing for the anchor bolts was about 1 cm too far apart. Or maybe some washers had a diameter 0.5 cm less than what is needed for an EF5 rating, cuz, you know. Link to comment Share on other sites More sharing options...
andyhb Posted May 4, 2014 Author Share Posted May 4, 2014 Hmm... Link to comment Share on other sites More sharing options...
Ground Scouring Posted May 4, 2014 Share Posted May 4, 2014 Hmm... This line says a lot about the survey's reasoning: "Additional structure strengthening mechanisms were unknown at time of survey." Clearly regional construction analysis played a big role in the decision not to upgrade despite what appears to be clear EF5 evidence. Link to comment Share on other sites More sharing options...
andyhb Posted May 4, 2014 Author Share Posted May 4, 2014 This line says a lot about the survey's reasoning: "Additional structure strengthening mechanisms were unknown at time of survey." Clearly regional construction analysis played a big role in the decision not to upgrade despite what appears to be clear EF5 evidence. The thing is that it says right there "destruction of engineered and/or well constructed residence; slab swept clean", with proper anchoring to the foundation/base plate. If it was unknown at the time of the survey (which seems like a very poor reason for not adjusting the rating), does this all the sudden mean the tornado can't be retroactively raised to an EF5? It happened with Rainsville in 2011. Link to comment Share on other sites More sharing options...
andyhb Posted May 4, 2014 Author Share Posted May 4, 2014 I see this was added to the LZK page, interpret it how you wish. To be fair, not every clean slab that was checked along the track of the tornado had cut nails. Several of these slabs had anchor bolts. However, there were signs that some of the bolts were improperly installed. At one home, for instance, there were no washers or nuts found on the bolts, and the bolts were not sheared off. In general, if survey crews found anchor bolts, and they were used as intended, the slabs were not clean. Link to comment Share on other sites More sharing options...
blackjack123 Posted May 4, 2014 Share Posted May 4, 2014 Nothing will convince me otherwise. This tornado deserved an EF5 rating and like I said no one will convince me otherwise. Heck even the Washington Illinois tornado last fall was a good candidate for an EF5 rating. Oh but EF5's don't happen in November or in Arkansas. Other factors in some tornadoes despite construction of homes that were rated high-end EF4 have been even more impressive than some recent EF5 tornadoes. That picture above seals the deal for an EF5 rating. There is more than an argument. Link to comment Share on other sites More sharing options...
Ensō Posted May 5, 2014 Share Posted May 5, 2014 Nothing will convince me otherwise. This tornado deserved an EF5 rating and like I said no one will convince me otherwise. Heck even the Washington Illinois tornado last fall was a good candidate for an EF5 rating. Oh but EF5's don't happen in November or in Arkansas. Other factors in some tornadoes despite construction of homes that were rated high-end EF4 have been even more impressive than some recent EF5 tornadoes. That picture above seals the deal for an EF5 rating. There is more than an argument. I don't really have a problem with the Washington, IL EF4 (though it may well have been rated F5 in the past), but I think this case is quite clear. As someone mentioned earlier in this thread, it's quite clear that the EF-scale, at least as it relates to high-end tornadoes, is no longer an assessment of intensity/damage/wind speed. It's an assessment of construction quality, and that's something entirely different and not particularly relevant to assessing tornado intensity. And it's even more clear that the rating a tornado receives depends heavily on where it occurs and the people who survey it. Link to comment Share on other sites More sharing options...
Buckeye05 Posted May 5, 2014 Share Posted May 5, 2014 ^The homes in Washington, IL were swept off of their floor joists/subfloors, not their foundations. It was visually impressive, but there is a big difference there. But I agree that the E Wicker St home in Vilonia is the final nail in the coffin for any remaining doubt about 200MPH+ winds at that location. Link to comment Share on other sites More sharing options...
MidwestChaser Posted May 5, 2014 Share Posted May 5, 2014 What site did you get that picture from? Link to comment Share on other sites More sharing options...
Ground Scouring Posted May 5, 2014 Share Posted May 5, 2014 The NWS Little Rock makes their case rest upon the fact that the well-built homes supposedly had debris left on their foundations immediately after the storm. Well, LZK should tell that to Tim Marshall et al. who found that several of the homes in Moore after 05/20/2013 had their bare slabs partially covered by debris from other destroyed structures. Thus, the mere presence of debris on the foundation is not necessarily due to/from/related to the home itself, but may have come from other structures, thus proving that debris does not mean the damage was not EF5 in intensity. Link to comment Share on other sites More sharing options...
blackjack123 Posted May 5, 2014 Share Posted May 5, 2014 Yeah I was mainly referring to the Vilonia tornado. Who actually did this survey? What I mean who assisted NWS in Little Rock with this survey? Link to comment Share on other sites More sharing options...
Buckeye05 Posted May 5, 2014 Share Posted May 5, 2014 What site did you get that picture from? It's from the LZK survey map. Home pictured is the one marked EF4 along E Wicker St in Vilonia. http://www.srh.noaa.gov/images/lzk/gis/tor042714a.kml The NWS Little Rock makes their case rest upon the fact that the well-built homes supposedly had debris left on their foundations immediately after the storm. Well, LZK should tell that to Tim Marshall et al. who found that several of the homes in Moore after 05/20/2013 had their bare slabs partially covered by debris from other destroyed structures. Thus, the mere presence of debris on the foundation is not necessarily due to/from/related to the home itself, but may have come from other structures, thus proving that debris does not mean the damage was not EF5 in intensity. I didn't see anything about that. Where does it say that debris covering the foundations came into play? LZK lists the main home in question as "slab swept clean". Link to comment Share on other sites More sharing options...
Ensō Posted May 5, 2014 Share Posted May 5, 2014 Yeah I was mainly referring to the Vilonia tornado. Who actually did this survey? What I mean who assisted NWS in Little Rock with this survey? Someone from TSA came in to assist whoever at LZK did the surveys, I didn't catch who though. Link to comment Share on other sites More sharing options...
Ensō Posted May 5, 2014 Share Posted May 5, 2014 It's from the LZK survey map: http://www.srh.noaa.gov/images/lzk/gis/tor042714a.kml For some reason they haven't updated that one yet. Someone had posted an updated .kmz on Twitter, which is where I got it from. I lost the link but I reuploaded it here for anyone who wants to look for themselves. https://www.dropbox.com/s/9xpvd1au74i0o4u/storm_survey.kmz Link to comment Share on other sites More sharing options...
Buckeye05 Posted May 5, 2014 Share Posted May 5, 2014 It worked for me when I clicked on the damage point. The pic doesn't load in the pop-up window but it still shows up if you click to enlarge it. Link to comment Share on other sites More sharing options...
Hoosier Posted May 5, 2014 Share Posted May 5, 2014 This event, like everything else, should get a final review before it becomes official in about 3 months. Perhaps we will see a change in the rating but I wouldn't hold my breath. Link to comment Share on other sites More sharing options...
Ground Scouring Posted May 5, 2014 Share Posted May 5, 2014 It's from the LZK survey map. Home pictured is the one marked EF4 along E Wicker St in Vilonia. http://www.srh.noaa.gov/images/lzk/gis/tor042714a.kml I didn't see anything about that. Where does it say that debris covering the foundations came into play? LZK lists the main home in question as "slab swept clean". The info comes straight from the survey: To be fair, not every clean slab that was checked along the track of the tornado had cut nails. Several of these slabs had anchor bolts. However, there were signs that some of the bolts were improperly installed. At one home, for instance, there were no washers or nuts found on the bolts, and the bolts were not sheared off. In general, if survey crews found anchor bolts, and they were used as intended, the slabs were not clean. http://www.srh.noaa.gov/lzk/?n=anchor0514.htm And then there's this image showing a large, brick-built, newer-looking building (a bank?) that was completely leveled and not even listed as a damage point by LZK: Link to comment Share on other sites More sharing options...
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