Asian American and Pacific Islander Heritage Month Spotlight: Dr. Tetsuya “Ted” Fujita

Tidal Basin with cherry blossoms and ducks (NPS photo)

By AMS President Anjuli S. Bamzai

Blossoming cherry trees are stars of springtime in Washington, D.C., and the most popular place to visit the cherry blossom trees is the Tidal Basin. Their bloom is one of the most joyful events of the year, awaited with much anticipation by tourists, meteorologists, local businesses, and the National Park Service.

Celebrating the friendship between the Japanese and American peoples, the Tidal Basin cherry trees were a gift from the Mayor of Tokyo to the United States in 1912. While the precise timing of peak bloom varies from year to year (April 4 on average, driven largely by winter/early spring temperatures), peak bloom has been occurring earlier due to warming trends. Furthermore, a combination of rising sea level and sinking land has necessitated plans for a new seawall that requires many existing trees to be removed. Yet the government of Japan has promised new trees to replace those that were lost.

This year’s beautiful blossoms strongly reminded me of the remarkable contributions of Japanese Americans — in particular Japanese American meteorologists. Our science would be especially bereft without the contributions of several scientists who, after receiving their advanced degrees at the University of Tokyo in the so-called “Syono school” of dynamic meteorology, immigrated to the U.S. from postwar Japan. Among them were Tetsuya Fujita, Akio Arakawa, Akira Kasahara, Kikuro Miyakoda, Takio Murakami, Katsuyuki Ooyama, Michio Yanai, and of course, Syukuro ‘Suki’ Manabe, one of the three recipients of the Nobel Prize in Physics in 2021.

Celebrating AAPI Heritage Month, in this post I chose to showcase the contributions of the legendary Dr. Tetsuya Theodore ‘Ted’ Fujita. Nicknamed “Mr. Tornado,” he linked tornado damage with wind speed and in 1971, developed the Fujita scale for rating tornado intensity based on ground and/or aerial damage surveys. He is also recognized as the discoverer of downbursts and microbursts, which are serious potential threats to aviation safety. Thus his discoveries made aviation safer.

Fujita (left) with John McCarthy, Inaugural Director of NCAR-RAP/RAL, in 1982. After studying tornadoes for over two decades, Fujita had just seen his first one in person. Photo: Texas Tech, found in Fujita’s memoir, “Memoirs of an Effort to Unlock The Mystery of Severe Storms During the 50 Years, 1942–1992,” in the Texas Tech Southwest Collection/Special Collections Library.

But let’s take a step back. How did Fujita get interested in tornadoes in the first place? In part, his involvement was yet another legacy of the Manhattan Project: Fujita began his life’s work studying damage in Hiroshima and Nagasaki in the aftermath of the atomic bombs.

Fujita was working as assistant professor in physics at Meiji College of Technology in Tobata, exactly halfway between the two cities. A couple of years earlier, in compliance with his dying father’s wishes, he had opted to go to Tobata for his studies in mechanical engineering rather than Hiroshima. In the month following the bombings, Fujita and his team of students went on an observational mission to study the blast zones at both sites. At Nagasaki, through studying the burn marks of various objects, Fujita had the goal of estimating the position of the atomic bomb when it exploded. At ground zero, most trees, though scarred black by radiation, were still standing upright while buildings were in ruins. Seen from above, it looked like a giant starburst pattern.

After WWII ended, he joined the University of Chicago. By a stroke of genius, the Japanese American meteorologist was able to draw comparisons between severe weather and the nuclear shock waves he had studied some twenty-five years earlier at Hiroshima and Nagasaki, through studying the debris and damage of tornadoes before cleanup. He led the development of the Fujita Scale to categorize tornado intensity, a modified version of which remains in use today.

Following the Super Outbreak of 3–4 April, 1974, which covered over 2,600 miles and produced nearly 150 tornadoes in an 18-hour period, Fujita carried out aerial and ground damage surveys covering over 10,000 miles. Through meticulous analysis of the observational data, he demonstrated the existence of smaller tornadoes — suction vortices — within the parent tornado. The aerial surveys also led to the discovery of microbursts.

Photo: Dr. Fujita as a professor of Geophysical Sciences at the University of Chicago, photo taken in April 1961. Special Collections Research Center, University of Chicago Library.

You can read more about his discovery of the downburst and its contributions to aviation safety (including his work as a principal investigator for the National Intensive Meteorological Research On Downburst [NIMROD] project) here.

In 2000, two of his former students organized the “Symposium on the Mystery of Severe Storms: A Tribute to the work of T. Theodore Fujita,” held at the 80th AMS Annual meeting. They were none other than Gregory S. Forbes from The Weather Channel and Roger M. Wakimoto from UCLA, both distinguished meteorologists in their own right. Roger was of course our AMS President in 2017–2018. The photo below shows the three of them at an event at the University of Chicago from the early 1980s.

Dr. Roger Wakimoto (left), Dr. Ted Fujita (middle) and Dr. Gregory Forbes (right), taken in the early 1980s when all were at the University of Chicago. Photo Courtesy of Roger Wakimoto, honorary member of the AMS.

You can read the proceedings of the Symposium here to get a fuller sense of Fujita’s immense contributions to atmospheric science. In this short piece, I have barely scratched the surface.

You can also learn about Fujita through the PBS American Experience series, which describes events and people who have shaped the landscape over the course of history. Fujita is profiled in the episode titled, “Mr. Tornado.”

Featured image: Cherry blossoms surround the Tidal Basin in Washington, D.C. Photo: National Park Service, Kelsey Graczyk

Anjuli is grateful to Katherine ‘Katie’ Pflaumer for providing useful edits.

Be There: Estimating Wind Speeds of Tornadoes and Other Windstorms

Tornado photo

By James LaDue, NOAA/NWS Warning Decision Training Division (symposium co-chair)

Did you know that the AMS is co-branding a standard with the American Society for Civil Engineers and that you can be involved as a member? For the past several years, both organizations have signed together to develop a standard on wind speed estimation for tornadoes and other severe storms. To learn more about this standard, and the methods it’s developing, the standards committee on Wind Speed Estimation is hosting a symposium this Thursday at the AMS 104th Annual Meeting, aptly named “Estimating Wind Speeds of Tornadoes and Other Windstorms.” In this conference you will learn more about how you can be involved in the process.

Ever since the EF scale was implemented in 2007, damage surveyors found reasons for improvement. They formed a grassroots stakeholder group in 2010 and published a paper in 2013 highlighting areas needing improvement. Then after the Joplin, MO tornado of 2011, an investigation led by NIST recommended that a committee be formed to improve the EF scale. But that’s not all there was to estimating wind speeds. New methods were maturing quickly to estimate winds in severe storms: methods such as Doppler radar, tree-fall patterns left behind tornadoes, probabilistic wind speed analysis forensics, multispectral passive remote sensing, and in-situ observations. Many of these methods can also be applied to other windstorm types.

The committee on Wind Speed Estimation, begun within the ASCE in 2015, is devoted to refining all of these methods into an ANSI standard (American National Standard).  Comprised of engineers, meteorologists, architects, forest ecologists, an arborist, and an emergency manager, we are now deep in the internal balloting phase of the standard’s individual chapters. While the ASCE provides the logistical support for our committee, the AMS was added and the standard co-branded under both organizations. The process by which a standard forms is one of the most rigorous vetting processes known in the STEM fields and often can take a decade or more. We’ve been conducting internal ballots for several years, and this may last a couple more. Once the internal balloting phase is over, the standard goes to a public comment phase.  

The Wind Speed symposium is designed to let you know how and why we have this standards process, how the methods are designed in the standard, and how you can be involved, especially when the public comment period commences. We have a panel discussion at the beginning to give you a chance to engage with the committee, followed by more in-depth presentations on the methods. There are also oral and poster presentations regarding new science coming out that could provide more advances in the standard and its application. We hope to see you there! 

Featured image: Photo of tornado with dust cloud near power lines in Matador, TX, taken 21 June 2023. Image credit: James LaDue.

The Estimating Wind Speeds of Tornadoes and Other Windstorms Symposium will be held Thursday, 1 February, 2024 at the AMS 104th Annual Meeting, in Baltimore and online. Learn more about the Symposium and view the program.

Southeasterners Perceive Tornado Risk Dangerously Different Than They Should, Especially at Night

While a major winter storm last month was plastering the United States from Texas and New Mexico to New England with heavy snow and ice, volatile conditions in the Southeast (SE) spawned damaging and deadly tornadoes. One of these overnight Monday, February 16, tragically took the lives of 3 people and injured 10 in coastal North Carolina. Such nocturnal tornadoes are common in the Southeastern U.S.—a unique trait—and represent an extreme danger to sleeping residents.


Compounding this problem, new research in the AMS journal Weather, Climate, and Society suggests there may be a deadly disconnect between tornado perception and reality in the region right when residents instead need an acute assessment of their tornado potential.
The article “Do We Know Our Own Tornado Season? A Psychological Investigation of Perceived Tornado Likelihood in the Southeast United States,” by Stephen Broomell of Carnegie Mellon University, with  colleagues from Stanford and NCAR, notes the tragic results of the regional misperception:

The recurring risks posed by tornadoes in the SE United States are exemplified by the significant loss of life associated with recent tornado outbreaks in the SE, including the 2008 Super Tuesday outbreak that killed over 50 people and the devastating 27 April 2011 outbreak that killed over 300 people in a single day.

Their survey of residents in seven states, from Louisiana and Arkansas to Georgia and Kentucky, representing the Southeastern region, finds that the residents perceive their tornado likelihood differently than meteorologists and experts familiar with Southeastern tornado risk. This puts them at great risk because residents’ experiences don’t match what actually happens where they live.

Broomell and his fellow researchers contend that Southeast residents may be misusing knowledge of Great Plains tornado events, ubiquitous in tornado chasing reality shows and social media videos, when determining their own risk. A fatal flaw since tornado behavior is different between the two regions.
WCAS SE tornado season survey2For starters, unlike in infamous “Tornado Alley” states of Texas and Oklahoma north through Nebraska and Iowa into South Dakota, the Southeast lacks a single, “traditional” tornado season, with tornadoes “spread out across different seasons,” Broomell along with his coauthors report, including wintertime. The Southeast also endures more tornadoes overnight, as happened last week in North Carolina. And they spawn from multiple types of storm systems in the Southeast, more so than in the Great Plains. This makes knowledge about residents’ regional tornado likelihood especially critical in Southeastern states.

Another recent study published in the Bulletin of the American Meteorological Society, “In the Dark: Public Perceptions of and National Weather Service Forecaster Considerations for Nocturnal Tornadoes in Tennessee,” by Kelsey Ellis (University of Tennessee, Knoxville), et al., surveyed residents of Tennessee and came away with similar findings about tornado timing: about half of Tennessee’s tornadoes occur at night, and yet less than half of those surveyed thought they would be able to receive nighttime tornado warnings.

Local forecasters and broadcast meteorologists as well as emergency managers are tuned into the mismatch. In the BAMS study, NWS forecasters said they fear for the public’s safety, particularly with nighttime tornadoes, because they “know how dangerous nocturnal events are”—fatalities “are a given,” some said.

Ellis and her colleagues recommended developing a single, consistent communication they term “One Message” to focus on getting out word about the most deadly aspect of the tornado threat. Forecasters, broadcasters, and emergency managers through regular and social media would then be consistent in their messaging to residents, the researchers state, decreasing confusion. For example:

Nighttime tornadoes expected. Sleep with your phone ON tonight!

With severe weather season ready to pop as spring-like warmth quickly overwhelms winter’s icy grip in the next couple of weeks, the nation’s tornado risk will blossom across the South and Southeast. And nocturnal tornado threats will only increase, particularly in the Southeast, as February turns into March, and then April—a historically deadly month.
For residents in places more prone to nighttime tornadoes, Ellis et al. say the ways to stay safe are clear:

Have multiple ways to get tornado warnings, do not rely on outdoor sirens, sleep with your phone on and charged during severe weather, and do not stay in particularly vulnerable locations such as mobile homes or vehicles.

"Sleep with your phone on!": Messaging for Nighttime Tornadoes

With Hurricane Delta poised to strike Louisiana today, the risk of embedded tornadoes will increase as rainbands spiral ashore, along with the primary threats of storm surge and damaging winds. Delta is forecast to plow well inland Friday night into the weekend, continuing a low risk for tornadoes, some of which could occur at night in Alabama, Mississippi and into southern Tennessee. The threat is more than a bit worrisome as new research in BAMS finds through phone surveys and followup interviews in Tennessee that people are woefully unprepared for nocturnal tornadoes.
In their article,” Kelsey Ellis and colleagues found a host of poor practices by residents when it comes to tornadoes at night. The authors recommend forecasters narrow their messaging about nocturnal tornadoes in the Southeast to a single important message to limit confusion.
Almost half of Tennessee’s tornadoes occur at night, as in other Southeast states with large numbers of nocturnal tornadoes, and are two-and-a-half times as deadly as daytime tornadoes. This creates detection, warning, and public response challenges. Yet, respondents in the western part of the state overestimated tornado occurrence at night while those in the east substantially underestimated the number.
Additionally, nearly half of participants in the survey say they rely on sirens to receive tornado warnings. This is despite the fact that sirens are not designed to warn people inside nor be loud enough to wake anyone up. Instead, Wireless Emergency Alerts (WEAs) “should be a constant,” the authors say. Also, people mentioned they rely on TV and social media for receiving warnings even though generally neither will wake you up.
The authors felt it was “dangerous” that even the more tech savvy and tornado aware respondents answered they were compelled to look outside for evidence of a tornado—even in the dark. Interviewees explained they were “checking for sounds instead of visual cues.”
NWS forecasters were also surveyed about nocturnal tornadoes. The forecasters mentioned the lack of ground truth and fear for public safety among challenges to the nighttime warning service. They noted few spotter or social media reports inform them if “the storm is actually showing the signs on the grounds that radar is indicating aloft.” Forecasters said they felt “fearful, worried, or nervous for the public during nocturnal tornadoes because fatalities ‘are a given.’”
The survey responses moved Ellis et al. to recommend a single-emphasis message be presented to residents to combat the nighttime tornado problem:

One strategy that may improve public safety during a nocturnal tornado event, and which addresses the forecaster challenge of communication prior to and during an event, is to develop “One Message”—a consistent message that EMs and the media use throughout broadcasts, briefings, and social media. Examples of messages could be: “Nighttime tornadoes expected. Sleep with your phone ON tonight!” or “Tornadoes will form quickly! Make plans now where you will take shelter!” or “If you live in a manufactured home, you may not have much time to seek shelter tonight!” One Message may decrease confusion for receivers, making them more likely to make safe decisions. Messages could similarly be used to dispel misconceptions about local geography in ways relevant to the specific listening area, for example: “You are not protected by nearby hills. Seek shelter immediately!”

With Hurricane Delta’s nighttime tornado threat ramping up, the authors suggest people use multiple ways to receive warnings, keeps phones on and charged, don’t rely on tornado sirens, and if possible relocate ahead of the weather from “particularly vulnerable” situations, such as mobile homes and vehicles.

“Sleep with your phone on!”: Messaging for Nighttime Tornadoes

With Hurricane Delta poised to strike Louisiana today, the risk of embedded tornadoes will increase as rainbands spiral ashore, along with the primary threats of storm surge and damaging winds. Delta is forecast to plow well inland Friday night into the weekend, continuing a low risk for tornadoes, some of which could occur at night in Alabama, Mississippi and into southern Tennessee. The threat is more than a bit worrisome as new research in BAMS finds through phone surveys and followup interviews in Tennessee that people are woefully unprepared for nocturnal tornadoes.

In their article,” Kelsey Ellis and colleagues found a host of poor practices by residents when it comes to tornadoes at night. The authors recommend forecasters narrow their messaging about nocturnal tornadoes in the Southeast to a single important message to limit confusion.

Almost half of Tennessee’s tornadoes occur at night, as in other Southeast states with large numbers of nocturnal tornadoes, and are two-and-a-half times as deadly as daytime tornadoes. This creates detection, warning, and public response challenges. Yet, respondents in the western part of the state overestimated tornado occurrence at night while those in the east substantially underestimated the number.

Additionally, nearly half of participants in the survey say they rely on sirens to receive tornado warnings. This is despite the fact that sirens are not designed to warn people inside nor be loud enough to wake anyone up. Instead, Wireless Emergency Alerts (WEAs) “should be a constant,” the authors say. Also, people mentioned they rely on TV and social media for receiving warnings even though generally neither will wake you up.

The authors felt it was “dangerous” that even the more tech savvy and tornado aware respondents answered they were compelled to look outside for evidence of a tornado—even in the dark. Interviewees explained they were “checking for sounds instead of visual cues.”

NWS forecasters were also surveyed about nocturnal tornadoes. The forecasters mentioned the lack of ground truth and fear for public safety among challenges to the nighttime warning service. They noted few spotter or social media reports inform them if “the storm is actually showing the signs on the grounds that radar is indicating aloft.” Forecasters said they felt “fearful, worried, or nervous for the public during nocturnal tornadoes because fatalities ‘are a given.’”

The survey responses moved Ellis et al. to recommend a single-emphasis message be presented to residents to combat the nighttime tornado problem:

One strategy that may improve public safety during a nocturnal tornado event, and which addresses the forecaster challenge of communication prior to and during an event, is to develop “One Message”—a consistent message that EMs and the media use throughout broadcasts, briefings, and social media. Examples of messages could be: “Nighttime tornadoes expected. Sleep with your phone ON tonight!” or “Tornadoes will form quickly! Make plans now where you will take shelter!” or “If you live in a manufactured home, you may not have much time to seek shelter tonight!” One Message may decrease confusion for receivers, making them more likely to make safe decisions. Messages could similarly be used to dispel misconceptions about local geography in ways relevant to the specific listening area, for example: “You are not protected by nearby hills. Seek shelter immediately!”

With Hurricane Delta’s nighttime tornado threat ramping up, the authors suggest people use multiple ways to receive warnings, keeps phones on and charged, don’t rely on tornado sirens, and if possible relocate ahead of the weather from “particularly vulnerable” situations, such as mobile homes and vehicles.

Website Tracks Public Understanding of Tornadoes

Imagine you live in a part of the country where few people have experienced tornadoes. It would make sense that your neighbors wouldn’t know the difference between a tornado watch or warning, or know how to seek safety.

A new, openly available online tool shows exactly that, by combining societal databases with survey results about people’s understanding of weather information. But there are some surprising wrinkles in the data. For example, the database drills down to county-level information and finds “noteworthy differences” within regions of similar tornado climatology.

How is it that Norman, Oklahoma, residents score higher in what people think they know of severe weather information than those in Fort Worth, Texas? And why is there a similar gap between what people actually do know, as tested in Peachtree City, Georgia, versus Birmingham, Alabama?

“Differences like this create important opportunities for research and learning within the weather enterprise,” say Joseph T. Ripberger and colleagues, who describe the weather demographics tool in a recently published Bulletin of the American Meteorological Society article. “The online tool—the Severe Weather and Society Dashboard (WxDash)—is meant to provide this opportunity.”

For example, in one key set of metrics, the WxDash website looks at survey data on how well people receive and pay attention to tornado warnings (reception), how well they understand that information (both “subjective” comprehension—what people think they know—and “objective” comprehension—what they actually know), and response to tornado warnings.

From the BAMS article, a figure showing knowledge and response to average person percentile (APP) estimates of tornado warning reception, subjective comprehension, objective comprehension, and response by county warning area (CWA). The inset plots indicate the frequency distribution of APP estimates across CWAs. These estimates compare the average percentile of all adults who live in a CWA to the distribution of all adults across the country. For example, an APP estimate of 62 indicates that, on average, adults in that CWA score higher than 62% of adults nationally. The range of APP scores is wide. CWAs range from 38 to 61 on the reception scale, 32 to 69 on the subjective comprehension scale, and 37 to 60 on the objective comprehension scale. Response scores vary less. Not surprisingly, all categories broadly reflect the higher frequency of tornadoes in middle and southeastern CWAs.
From the BAMS article, a figure showing knowledge and response to average person percentile (APP) estimates of tornado warning reception, subjective comprehension, objective comprehension, and response by county warning area (CWA). The inset plots indicate the frequency distribution of APP estimates across CWAs. These estimates compare the average percentile of all adults who live in a CWA to the distribution of all adults across the country. For example, an APP estimate of 62 indicates that, on average, adults in that CWA score higher than 62% of adults nationally. The range of APP scores is wide. CWAs range from 38 to 61 on the reception scale, 32 to 69 on the subjective comprehension scale, and 37 to 60 on the objective comprehension scale. Response scores vary less. Not surprisingly, all categories broadly reflect the higher frequency of tornadoes in middle and southeastern CWAs.

 

WxDash combines U.S. Census data with an annual Severe Weather and Society Survey (Wx Survey) by the University of Oklahoma Center for Risk and Crisis Management. The database then “downscales” the broader scale information to the local level, in a demographic equivalent to the way large scale climate models downscale to useful information on regional scales.

The site also provides information on public trust in weather information sources, perceptions about the efficacy of protective action, vulnerability to beliefs about a variety of tornado myths, and other weather-related factors that can then be studied in light of regional and demographic factors.

Some of the key findings seen in the database:

  • Men and women demonstrate roughly comparable levels of reception, objective comprehension, and response, but men have more confidence in subjective warning comprehension than women.
  • Tornado climatology has a relatively strong effect on tornado warning reception and comprehension, but little effect on warning response.
  • The findings suggest that geography, and the community differences that overlap with geographic boundaries, likely exert more direct influence on warning reception and comprehension than on response.

Even the relatively expected relation of severe weather climatology to severe weather understanding is problematic, Ripberger and colleagues write.

Tornadoes are possible almost everywhere in the US and people who live on the coasts can move—both temporarily and permanently— throughout the country. These factors prompt some concern about the low levels of reception and comprehension in some communities, especially those in the west.

In addition to interacting with these data, you can download one of the calculated databases for community-scale information, the raw survey data, and the code necessary to reproduce the calculations.

The idea is social scientists can dig in and figure out why what we know about weather isn’t nearly as closely correlated with what we experience as we might think. The hope is an improvement in public education and risk communication strategies related to severe weather.

10-m Resolution Quarter-Trillion Gridpoint Tornadic Supercell Simulation Mesmerizes

An exceptionally high resolution simulation of a supercell thunderstorm fascinated conferees Tuesday at the AMS 100th Annual Meeting in Boston. Leigh Orf of the University of Wyoming presdented imagery and animations of the simulation that ran on the Blue Waters Supercomputer. With a 10 m grid spanning 11,200 X 11,200 X 2,000 (251 billion) grid volumes, the 270 TB subdomain contains the entire life cycle of the tornado, including 10 minutes prior to tornado formation.

Image created with VAPOR3 of a 10-m supercell simulation. (a) Volume rendered cyclonic vertical vorticiy, highlighting the 3D structure of the tornado shortly after formation.
Image created with VAPOR3 of a 10-m supercell simulation. (a) Volume rendered cyclonic vertical vorticity, highlighting the 3D structure of the tornado shortly after formation. The 2D surface field traces the maximum surface cyclonic vertical vorticity, providing a representation of the tornado’s path. The view is following the tornado’s path. (b) As in (a), but later in the simulation when the tornado exhibits a multiple vortex structure. (c) Volume rendered cloud mixing ratio, with parameters chosen to present a quasi-photorealistic view of the cloud field. The 2D surface field traces the minimum pressure found in the tornado’s path. (d)  As in (a) and (b), but a different, wider view and utilizing different opacity and color map choices. The vortex to the left, which merges with the tornado later in the simulation, is weaker than the nascent tornado as evidenced by the vortex’s more transparent and darker visual presentation and path.

 

Tornado Researchers Gather to Improve Wind Speed Estimation

The Wind Speed Estimation (WSE) standards committee–jointly supported by AMS and the American Society of Civil Engineers–is holding its 9th meeting this week in conjunction with an NSF-funded Tornado Hazard Wind Assessment and ReducTion Symposium (THWARTS) at the University of Illinois in Champaign-Urbana.
The WSE committee began in 2014 to develop standards for an improved process to estimate extreme storm winds. Currently, NWS and private post-storm damage surveys use the EF-Scale and treefall pattern analysis, real-time radar and in situ observations, remote sensing, and forensic investigations. The WSE committee includes a data archival team as well as an international working group to broaden the scope of the standard. (Click here for more information about the committee.)
WSE
This is the second joint meeting of WSE/THWARTS and will focus on sharing the latest findings on the multidisciplinary aspects of severe local storms, including the fields of meteorology, wind science and engineering, structural engineering, social science, and policy. A flyer about the symposium with basic information is available online.
Keynote speaker for THWARTS will be Erik Rasmussen. He was the field coordinator of the first of the VORTEX projects in 1994-1995 and a lead principal investigator for VORTEX2 from 2009-2010 and VORTEX-SE from 2016-2017. He currently consults with NOAA’s National Severe Storms Laboratory and the Cooperative Institute for Meteorological Satellite Studies.
The WSE meeting begins after the final session of THWARTS. The meeting is the first step toward a request for public comment on WSE, likely next year.

Making Sure No Tornado Damage Is Too Small

Planetary, synoptic, meso-alpha, meso-beta, local, and more—there are atmospheric scales aplenty discussed at AMS meetings. Enter microtopography, a once-rare word increasingly appearing in the mix in research (for example, here and here).
The word is also coming up as researchers are getting new tools to examine the interaction of tornadoes with their immediate surroundings. Microtopography looks like a potential factor in tornadic damage and in the tornadoes themselves, according to an AMS Annual Meeting presentation by Melissa Wagner (Arizona State Univ.) and Robert Doe (Univ. of Liverpool), who are working on this research with Aaron Johnson (National Weather Service) and Randy Cerveny (Arizona State Univ). Their findings relate tornado damage imagery to small changes in local topography thanks to the use of unmanned aerial systems (UASs).
Microtopographic interactions of tornadic winds were captured in their UAS imagery. Here’s the 5-meter resolution RapidEye satellite imaging of a 30 April 2017 Canton, Texas, tornado path (panel a) versus higher-resolution UAS imaging:
UAS damage figure 1
 
The UAS surveys show that tornadic winds interact with sunken gullies, which appear as unscarred, green breaks (circled in red) in the track of browned damaged vegetation:
UAS damage fig. 3
Erosion and scour are limited within the depressed surfaces of the gullies compared to either side. In another section of the track, track width increases with an elevation gain of approximately 74 feet, as shown in a digital elevation model and 2.5 cm resolution UAS imagery:
UAS damage 3+
The advent of unmanned aerial vehicles (UAVs) has opened new windows on tornado damage tracks. Decades ago, damage surveys took a big leap forward with airplane-based photography that provided a perspective difficult to achieve on the ground. Satellites also can provide a rapid overview but in relatively low resolution. UASs fly at 400 feet—and are still limited to line-of-sight control and the logistics of coordinating with local emergency and relief efforts, regulatory and legal limitations, not to mention still-improving battery technology.
However, UASs provide a stable, reliable aerial platform that benefits from high-resolution imaging and can discern features on the order of centimeters across. Wagner and colleagues were using three vehicles with a combined multispectral imaging capability that is especially useful in detecting changes in the health of vegetation. As a result their methods are being tested primarily in rural, often inaccessible areas of damage.
UAS technologies thus can capture evidence of multi-vortex tornadoes in undeveloped or otherwise remote, vegetated land. The image below shows a swath with enhanced surface scour over two hills (marked X). The arrow on the right identifies speckled white surface erosion, part of the main tornado wedge. Such imagery explains why, among other research purposes, Wagner and Doe are developing the use of UASs in defining tracks and refining intensity-scale estimates.
UAS damage Figure 4

A Tale of Two Studies: Varied Perspectives at the AMS Meeting

by Maggie Christopher, Valparaiso University
On Sunday students presented nearly 200 posters of their research in grad school and summer internships. With so many topics covered, the session covered a variety of perspectives—often multiple perspectives on similar questions.
For example, two students from different universities did individual studies of the socioeconomic factors in fatalities due to tornadoes. But while Shadya Sanders from Howard University compared two case studies, Omar Gates, from the University of Michigan, set one tornado case in a climatological perspective.
Sanders compared the Joplin, Missouri, and Tuscaloosa, Alabama, tornadoes in 2011. Sanders looked at the differences in death rates for race, age, gender, and housing structures in each storm. She found, for example, a high rate of death amongst women, which she said is unusual compared to other data she looked at. Women generally will take the suggested protective action when warnings are issued.
Sanders also noticed that in Tuscaloosa people aged 21-30 died at a higher rate, probably because the University of Alabama is located in the city of Tuscaloosa. By contrast, in Joplin, more retail business were located in the path of the storm, rather than houses.
Similarly, Gates studied the effect of tornado outbreaks as climate changes. He hoped to show the risk of tornadoes striking cities. He focused his research on Oklahoma, and specifically the May 3, 1999 tornado in Moore. Gates used reanalysis data with the North American Regional Reanalysis (NARR), and also utilized 2010 Census Data, which included demographic information such as gender, race, age, and housing units.
Using ARCgis, Gates put together risk assessment maps for vorticity, moist static energy, and wind shear. These maps were then put together, along with the actual storm track, to locate the highest risk of tornadoes for that day.
Even with different approaches, Shayda and Gates had similar goals for their work. Shayda held focus groups in both cities to see what kinds of warnings citizens would find most helpful. She wants to insure that warnings get out to everyone, and she hopes to continue her research throughout the rest of the United States. Similarly, Gates hopes that continuing to look at the socioeconomic effects of tornadoes will lead to watches, outlooks, and warnings that are easier for people to decipher, saving lives.