Avagene Moore: Welcome to the EIIP Virtual Library! Avagene Moore: Our topic today is "The Forgotten F5: The Lawrence County Supercell during the Middle Tennessee Tornado Outbreak of April 16, 1998." Avagene Moore: Before giving more information about our presentation and our speaker, we will quickly go through some information relative to conduct of the EIIP Virtual Forum. Avagene Moore: Links to the paper under discussion plus the author's bio and the Nashville NWS are provided on today's background page at http://www.emforum.org/vlibrary/010321.htm . Avagene Moore: For any first-timers, when you see a blue web address, you can click on it and the referenced Web page will appear in a browser window. Our speaker will use a few URLs in his presentation. Avagene Moore: After you are done viewing, bring your chat window back to the top. After the first link, the browser window may not come to the top automatically, so you will need to bring it forward. Avagene Moore: We will begin today with a formal presentation, followed by an interactive Q&A session. We will provide the protocol for submitting questions when we start that section. Avagene Moore: It is a pleasure to host today's session. The paper, "The Forgotten F5: The Lawrence County Supercell during the Middle Tennessee Tornado Outbreak of April 16, 1998," is the result of the research of four gentlemen from the Weather Forecast Office in Nashville, Tennessee: ... Avagene Moore: John D. Gordon, Bobby Boyd, Mark A. Rose, and Jason B. Wright. Avagene Moore: We appreciate Mark Rose for being here today to present the results of this collaborative effort. Mark is a meteorologist at the National Weather Service Office in Old Hickory, Tennessee. Avagene Moore: Mark has authored or co-authored many technical papers, including publications in Weather and Forecasting, National Weather Digest, and the National Weather Association's Electronic Journal of Operational Meteorology. Avagene Moore: Please help me welcome Mark Rose -- thank you for joining us today, Mark. I turn the floor over to you now. Mark Rose: Hi. Thanks for having me. Mark Rose: On April 16, 1998, a tornado outbreak struck middle Tennessee. Mark Rose: More than 20 supercells were identified by radar, and 12 tornadoes were confirmed -- the fifth largest tornado outbreak in middle Tennessee's history. Mark Rose: The Warning & Forecast Office (WFO) in Old Hickory (OHX) issued a record 200 severe weather warnings on April 16, including 106 tornado warnings, in less than 18 hours. Mark Rose: The Nashville metropolitan area was struck by three tornadoes- one rated F3, and two rated F2. Mark Rose: The F3 hit the downtown area. Mark Rose: However, the most violent and dangerous tornado of the entire event, the Lawrence County F5, was nearly forgotten. Mark Rose: Please see figure 1 at http://www.srh.noaa.gov/bna/tornado/images/041698a.jpg Mark Rose: There may be two reasons why the Lawrence County tornado did not receive the attention of the Nashville tornadoes: Mark Rose: 1) it struck four remote counties in southwest middle Tennessee, and 2) a major metropolitan area (Nashville) was hit by three tornadoes. Mark Rose: The resulting intensive media coverage of the Nashville tornadoes simply overshadowed the impact of F5 winds in rural Lawrence County. Mark Rose: Official National Weather Service (NWS) records, obtained from the Storm Prediction Center (SPC), in 1999 listed three F5 tornadoes in Tennessee since records began in 1950. Mark Rose: Extensive research by the authors has shown that these three ratings are likely erroneous. Mark Rose: The lead author worked extensively with the SPC to consider downgrading these three F5s, which occurred in 1952 and 1974, to F4 ratings. Mark Rose: Besides discussion of the Lawrence County F5 tornado, this forum will include proposals to downgrade the three former F5 tornadoes, ... Mark Rose: and why the authors feel the Lawrence County F5 tornado of 1998 is the only legitimate F5 in Tennessee history. Mark Rose: On April 16, 1998, Nashville became the first major U.S. city (:100,000) in nearly 20 years to be struck by an F2 (or larger) tornado in the downtown area. Mark Rose: Shreveport, LA took two direct hits in 1978: April 17 (F2) and December 3 (F4). Mark Rose: On the morning of April 16, local media began continuous live coverage of the tornado outbreak. Mark Rose: This coverage rapidly intensified to a national level when Nashville was struck by an F3 tornado in the downtown area at 3:30 p.m. Mark Rose: All three national news networks either led off with coverage of the Nashville tornadoes or reported it during the first five minutes of the newscast. Mark Rose: The local, state, and national news justifiably focused on the Nashville tornadoes, thus greatly overshadowing the Lawrence County F5. Mark Rose: Around daybreak on April 16, showers and thunderstorms from west Tennessee and northern Mississippi moved into southwest middle Tennessee. Mark Rose: This convection left an "outflow boundary" across Wayne and Lawrence Counties of southwest middle Tennessee. Mark Rose: We hypothesize this boundary played a significant role in the formation of the Lawrence County tornado. Mark Rose: The severe thunderstorm that spawned this tornado formed over McNairy County (3 counties west of Lawrence). Mark Rose: The storm rapidly developed. Mark Rose: The initial tornado warning for Wayne County (1 county west of Lawrence) was issued at 3:43 p.m. Mark Rose: Seven minutes later, an F4 tornado began 11 miles south of Clifton in Wayne County. Mark Rose: The tornado was one mile wide at times, tracked 23 miles in Wayne County, killing 3 people, and injuring another 6. Mark Rose: Please see figure 2 at http://www.srh.noaa.gov/bna/research/images/f51.jpg Mark Rose: Please note that 3 tornadoes are being tracked simultaneously, with the Lawrence County storm in full force. Mark Rose: The initial tornado warning for Lawrence County was issued at 3:56 p.m., with the storm crossing into Lawrence County at 4:15 p.m. Mark Rose: Based on aerial and ground storm surveys, the tornado intensified and produced damage, including some F5 damage, for 50 additional minutes. Mark Rose: This one mile wide violent tornado struck largely rural areas of Lawrence County for 23 miles. Mark Rose: Fortunately, no one else was killed, although an additional 21 persons were injured. Mark Rose: I have two damage photographs for you to load. Mark Rose: Please see figure 3 at http://www.usit.com/mottrd/House1.jpg and figure 4 at http://www.srh.noaa.gov/bna/research/images/f58.jpg Mark Rose: It completely leveled many well constructed homes, wiping the foundations clean, debarked several trees, ... Mark Rose: and hurled a one-ton pickup truck more than 100 meters, all of which are described as F5 damage. Mark Rose: Overall, the storm tracked 62.5 miles across Wayne, Lawrence, and Maury Counties before lifting. Mark Rose: In addition to the 3 fatalities, 35 injuries occurred across the 3 counties. Mark Rose: According to the SPC database there have been three F5 tornadoes in Tennessee. Mark Rose: The first occurred on March 21, 1952 in Marshall County, Mississippi and Fayette County, in west Tennessee, which is one county east of Shelby County (Memphis). Mark Rose: The second and third F5s occurred in Lincoln and Franklin Counties in middle Tennessee during the Super Outbreak of April 3, 1974. Mark Rose: One of the co-authors, the legendary Bobby Boyd, who worked the Super Outbreak as a radar operator, questioned the 1974 ratings. Mark Rose: Mr. Boyd's thorough memory of the 1974 Super Outbreak led to a chain of events which shifted the scope of the paper. Mark Rose: The paper's original focus widened from a case study to include a detailed examination of former F5 tornadoes in Tennessee. Mark Rose: And now for a short history lesson... Mark Rose: In 1973, Fujita and Pearson created the F-scale for rating tornadoes. Mark Rose: A few years later, Dr. Schaeffer at the National Severe Storms Forecast Center (now the SPC) hired more than 50 college students... Mark Rose: to rate tornadoes that occurred prior to the NWS F-scale implementation. Mark Rose: One student was hired per state, except Texas, which required several students. Mark Rose: The 1952 storm was rated by one student, who used such data as photographs, newspaper articles, and information from emergency management. Mark Rose: The storm originated near Byhalia, Mississippi and ended near Moscow, Tennessee. Mark Rose: The college student rated the storm F4 in Mississippi and F3 in Tennessee. Mark Rose: However, the SPC database showed this storm as F5. Mark Rose: Mr. Boyd conducted an independent survey of the 1952 storm, much like Grazulis. Mark Rose: Mr. Boyd traveled to Fayette County, visited several newspaper offices, and the Tennessee State Library and Archives in Nashville. Mark Rose: The only evidence which might suggest the possibility of an F5 was a reference in the Memphis Sommerville Gazette of a "concrete block building being destroyed." Mark Rose: Based on newspaper accounts not indicating "incredible damage" in Fayette County, ... Mark Rose: the authors believe the concrete building referenced was probably not a steel-reinforced structure. Mark Rose: The authors concur with the student analyst and Grazulis. Mark Rose: Mr. Boyd was the primary radar operator at the Weather Service Meteorological Observatory at OHX during the super outbreak of 1974 and vividly remembers the event. Mark Rose: From discussions with several NWS employees, including the former state climatologist, Mark Rose: the authors were unable to locate anyone who recalled whether the NWS had performed a storm disaster survey in middle Tennessee. Mark Rose: However, Professor Fujita and some of his graduate students performed both ground and aerial surveys. Mark Rose: Furthermore, the authors researched several newspaper articles and pictures and spoke with the Lincoln County, TN Emergency Management Agency. Mark Rose: All articles the authors researched indicated F3 and F4 damage in Tennessee and Alabama with both tornadoes. Mark Rose: In fact, there was "devastating damage," including well- constructed homes leveled, steel structures badly damaged, and many deaths. Mark Rose: However, the authors were unable to locate reference to the "incredible damage" that results from an F5. Mark Rose: The authors sent a detailed letter to the SPC recommending the two tornadoes from 1974, and the 1952 tornado mentioned above, be downgraded to F4. Mark Rose: The SPC agreed to all three of these changes. Mark Rose: The SPC database now reflects the conclusions of Professor Fujita's map of 1974, and Grazulis' 1952 tornado write-up. Mark Rose: In conclusion... Mark Rose: The April 16, 1998 tornado outbreak was a wake-up call to most of the nation. Mark Rose: Tornadoes can hit large metropolitan areas. Mark Rose: In fact, Nashville, the nation's 16th largest city, was struck by 3 tornadoes. Mark Rose: The authors suggested that the three former F5 tornadoes in Tennessee should be reclassified as F4. Mark Rose: These changes have been adopted, making the April 16, 1998 Lawrence County tornado the only documented F5 in the history of Tennessee. Mark Rose: This concludes my presentation. Avagene Moore: Thank you, Mark. As a citizen of Lawrence County, TN, I remember the F5 all too well although I was several miles south of the tornado's path. Good presentation. Avagene Moore: As stated earlier, I will now review the protocol for submitting questions ... Avagene Moore: Audience, please enter a question mark to indicate you wish to be recognized. After inputting your ? to the screen, compose your question or comment but hold it until you are recognized before hitting the Enter Key or clicking on Send. Avagene Moore: We now invite your questions and comments. Amy Sebring: ? Roger Fritzel: ? Avagene Moore: Input your ? if you have a question. Amy, you are the first. Please input when you are ready. Amy Sebring: Besides correcting the technical record Mark, do the authors hope to bring more attention to this F5 in general? ... Mark Rose: Amy, ... Amy Sebring: since it did not get that much attention in the media at the time? Regina Blissett: ? Mark Rose: Well, that is the whole purpose of this paper... Mark Rose: This makes the seventh time our study has been presented... Mark Rose: The paper is also being published in the National Weather Digest, which is circulated all over the country... Mark Rose: Keep in mind that there were no studies done on the Nashville tornado. Avagene Moore: Roger, you are next, sir. I might add that the paper was presented in our community just a few weeks ago. Roger Fritzel: Is / was Grazulis the student assigned to research Tenn.? Mark Rose: Roger, actually Tom Grazulis is a college professor. ... Judy Jaeger: ? Mark Rose: He has spent more than a quarter century of his life researching tornadoes. ... Mark Rose: He published a comprehensive book a few years ago with the results of his study. ... Mark Rose: He also encouraged us to pursue certain avenues to have the SPC database corrected. Avagene Moore: Regina, your question, please. Folks input your ? if you have a question or comment. Regina Blissett: That tornado was absolutely unbelievable. How wide was it? What is the history of other F5's in our nation? Mark Rose: Regina, ... Mark Rose: It was a mile wide at its worst. ... Mark Rose: The history of F5's in the U.S. are that they are very rare and very deadly. ... Mark Rose: The full version of our paper mentions some former F5's that have occurred in recent years. Avagene Moore: Judy, please. Judy Jaeger: Do Tennessee tornadoes typically stay on the ground as long as this one? (Our Georgia storms occur and disappear in less than ten minutes.) Mark Rose: Judy, ... Amy Sebring: ? Mark Rose: Tornadoes in Tennessee typically do not stay on the ground that long. ... Avagene Moore: ? Mark Rose: I don't know how many have tracked for 62.5 miles. ... Mark Rose: but they are certainly very rare. ... Mark Rose: As you say, they usually come and go in 10 to 20 minutes. Avagene Moore: Amy, please. Amy Sebring: It appears that there was a substantial lead in the warning time from Wayne County. Is this attributed to the Doppler technology? Did the warnings make a difference do you think, that is, are they taken seriously? Mark Rose: Amy, thank you for asking that. ... Mark Rose: The Doppler technology DOES give us the ability to give large lead times on warnings. ... Mark Rose: especially large supercells like the Lawrence County storm. ... Mark Rose: People react to warnings differently. ... Mark Rose: Because Lawrence County has such a history of severe weather, ... Mark Rose: they tend to take warnings more seriously, ... Mark Rose: whereas others do not. ... Mark Rose: It also depends on how the warning is worded. ... Mark Rose: A warning that says "Doppler radar indicated a tornado", ... Mark Rose: will be taken less seriously than one that says "A large tornado has been sighted near Lawrenceburg". Avagene Moore: I have a comment re: the F5 tornado -- as a lifelong resident of this county, it is still very startling to me to see where the tornado passed over certain roadways. The wooded areas are gone and the whole area very different. And yes, people here do take the warnings very seriously. Avagene Moore: (Other questions? Input your ? mark now.) Amy Sebring: ? Avagene Moore: Amy, please. Rfoltman: ? Rick Amy Sebring: Has the Nashville event made a difference in the emphasis in Tennessee ... Amy Sebring: re preparedness and mitigation for example? If you know. Mark Rose: Amy, funny you should mention that. ... Mark Rose: The National Weather Service has implemented a program called "Storm Ready", ... Judy Jaeger: ? Mark Rose: where a town or city takes certain measures of severe weather preparedness, ... Mark Rose: and is certified by the NWS as being "Storm Ready". ... Mark Rose: Nashville is the first city in middle Tennessee to be certified. Avagene Moore: Rick, your question is next, please. Rfoltman: Mark, 1) What are the estimated winds with an F5 and 2) Should windows in office buildings in cities be laminated? Mark Rose: Rick, the estimated wind speeds with an F5 are 261 to 318 mph. ... Mark Rose: As far as laminating windows? I don't know how much good that does. ... Amy Sebring: ! Mark Rose: And with an F5, it doesn't matter what you do. Avagene Moore: Judy, please. Judy Jaeger: Are Safe Rooms or storm shelters prevalent in Lawrence County?? There is so little you can do to mitigate tornado damage. Mark Rose: Judy, I'll let Avagene answer that. Avagene Moore: OK. Don't think there are many Safe rooms at this point ... Avagene Moore: but there is a gentleman here who is selling concrete storm shelters and doing quite well. The whole idea has been sold to the community as a necessity. Avagene Moore: Amy has a comment. Amy Sebring: Just wanted to mention that we had a previous session on the StormReady program with John Ogren who is here today. For further info, see http://www.emforum.org/vclass/000308.htm . John Ogren: ! Amy Sebring: ? Avagene Moore: Yes, good session. John has a comment too. John Ogren: Or go to www.nws.noaa.gov/stormready Avagene Moore: Thanks, John. Amy, please. Amy Sebring: Regarding tornadoes hitting metropolitan areas, the Fort Worth tornado was after Nashville I believe ... Amy Sebring: how did that compare to the Nashville event if you know? Avagene Moore: (Other questions? Pop in your ? while we have Mark online with us.) Mark Rose: Amy, ... Mark Rose: I believe the Fort Worth storm was an F2, but caused more damage in the downtown area than in Nashville. Judy Jaeger: ? Avagene Moore: Other questions, folks? Judy, your question, please. Amy Sebring: ? Judy Jaeger: What happened to the windows in Nashville office buildings?... Mark Rose: Judy, many of them shattered. ... Mark Rose: Downtown was completely closed to traffic the following day. ... Mark Rose: The clean-up took some time, with all the glass. Judy Jaeger: Several years ago, we stopped telling folks to tape their windows in the face of hurricanes, because flying shards of glass were worse than flying bits of glass. Avagene Moore: Further comment, Mark? Mark Rose: I would have to agree with that. ... Mark Rose: In high winds, windows are going to get blown out anyway, ... Mark Rose: no matter what you do. ... Mark Rose: I guess its better to have a window shatter than to have it flying through the air intact. Avagene Moore: Amy, you are next, please. Amy Sebring: Mark, you mentioned that you and the other authors have been presenting these findings. Do you plan to collaborate in the future, have further study ideas on the drawing board so to speak? Mark Rose: Amy, ... Avagene Moore: ? Mark Rose: There was a second study done by me, one of the meteorologists who worked the event, ... Mark Rose: and an engineer named Tim Marshall. ... Mark Rose: We took some of the Doppler radar imagery, with radar- estimated wind speeds, ... Mark Rose: and did a correlation between wind speeds, and damage. ... Mark Rose: A link to the abstract of this study can be found at http://www.srh.noaa.gov/bna/research.htm ... Mark Rose: However, no further plans are in the works for another research effort. ... Mark Rose: We will always be willing to present our findings. ... Amy Sebring: ? Mark Rose: And I have never been involved in a project that has gotten as much airplay. Avagene Moore: Mark, we all know that warnings are critical. In your opinion, what should cities like Nashville and Lawrenceburg promote for the best, timely warnings? I remember Nashville pushing sirens. I have mixed feelings about sirens. Tom Heath: ? Mark Rose: Avagene, ... Rfoltman: ? Mark Rose: sirens are fine in small towns, where everybody can hear them. ... Mark Rose: But in big cities, I don't know. Sometimes they can be unreliable. ... Don Hartley: ? Mark Rose: Of course, we always promote NOAA Weather Radio as being absolutely the fastest way to receive severe weather warnings. Avagene Moore: Thanks. Amy, next, please. Amy Sebring: Has the Fujitsu scale stood up well over time? Has it proven useful? Can it be improved? Mark Rose: Amy, ... Mark Rose: As far as I am concerned, the Fujita scale cannot be improved upon. ... Mark Rose: There are always ideas floating around about how it can be fine tuned, but it has proven a very reliable scale of tornado intensity. Avagene Moore: Tom, your question, please. Tom Heath: The 'hooks' on fig 2 are very distinct. How good a predictor are they? Mark Rose: Tom, ... Mark Rose: Hooks, at least very distinct ones as shown in the figure, are quite reliable. ... Mark Rose: Before Doppler technology, hooks were the only method by which tornado warnings were issued by radar. ... Mark Rose: But now, we don't usually issue radar-based tornado warnings without looking at a storm's wind profile. Avagene Moore: Rick, please. Rfoltman: Mark, should the use of spotters be emphasized? Mark Rose: Rick, ... Amy Sebring: ! Mark Rose: We cannot overemphasize the use of spotters. ... Mark Rose: They are our best means for gathering information about storms in progress. ... Mark Rose: One of the things we stress in spotter presentations are what we, the meteorologists see (radar images), ... Mark Rose: and what the spotter sees (actual storms, tornadoes, hail, wind damage, etc.). Avagene Moore: Don, your question, please. (We have time for one or two more questions. Input your ? please.) Don Hartley: Sirens should only be one of several components of a warning package which includes, EAS, NOAA Weather Radio, faxes and pages, etc. Sirens are a particularly political thing here in West Alabama. After our killer F4 in December every neighborhood wants one....But Mark, I'm more concerned by automated radio stations that don't carry local severe weather EAS activations. During our tornado warning some members of the public report that a couple of stations never carried the warning. That's a real real weakness in the warning chain. Mark Rose: Don, indeed. ... Mark Rose: Our warnings always carry the phrase "EAS ACTIVATION REQUESTED" as part of the header. ... Mark Rose: Of course, radio and TV stations are not REQUIRED to carry our warnings. ... Mark Rose: But, I think it is a good policy, as it is a matter of public service. Again, that's why we always push NOAA Weather Radio. Avagene Moore: Amy, you have a comment. Please go ahead. And then we will wrap up the session. Amy Sebring: See also the Storm Prediction Center site at http://www.spc.noaa.gov/ which has very dramatic photos of tornadoes at the moment. For a tornado FAQ sheet see http://www.spc.noaa.gov/faq/tornado/ ... Amy Sebring: the F-scale is found at http://www.spc.noaa.gov/faq/tornado/f-scale.html Avagene Moore: Thanks, Amy. Mark, closing remarks? Mark Rose: Well, again thanks for asking me to do this. ... Mark Rose: I enjoyed the Mark Rose: Q & A session... Mark Rose: I wish you all the best. Avagene Moore: Thank you very much for being an informative presentation, Mark. We appreciate your time and effort on behalf of the EIIP Virtual Forum. Please stand by a moment while we take care of a couple of announcements. Avagene Moore: Next week, Wednesday March 28, 12:00 Noon EST, the Tech Arena features a session entitled "Emergency Management Content and Collaboration: Incident Master Portal Fills The Gap." Our special guest speaker will be James W. Morentz, Ph.D., CEO, Essential Technologies, Inc. Avagene Moore: Please mark your calendar and make plans to join us next week. Avagene Moore: Audience, we appreciate your presence and participation today. We will adjourn the EIIP Virtual Library at this time. Please feel free to express your personal appreciation to Mark for his presentation.