Tornado Size and Intensity Estimates

The 05/31/2013 El Reno, OK tornado was given an Enhanced Fujita (EF)-5 rating and declared the widest tornado ever recorded at 2.6 miles wide.

How do we get this information?

I spent a lot of time in my M.S. program at Purdue being quizzed by my committee and other scientists about tornado size. It’s a tricky subject. Thankfully my research, at least as I last left it, was not dependent on any distance parameters, so my defense didn’t involve much beating around the tornado bush on size questions. But I was working with DOW data, and Josh, Karen, and company have to deal with this question a lot.

First of all, the EF scale was developed to expand on the original Fujita scale, which connected the Beaufort and Mach scales.

Fujita Scale

The Fujita scale lacked the detailed damage indicators that surveyors use to estimate Enhanced Fujita scale ratings today. If you compare the numbers, significant differences don’t appear until the higher (E)F numbers, for the “significant tornadoes.” The Fujita scale relates wind speeds to damage, while the Enhanced Fujita scale relates damage to wind speeds.

There are problems with the (E)F scale, but it is often the best information that we have to use when estimating tornado intensity. This method really falls apart when there are not enough damage indicators to use to rate the tornado–not because the storm was incapable of producing damage, but because it occurred in one of the oh-so-common wide open areas in middle America.

For years now we have been attempting to relate Doppler radar intensity estimates to the damage estimates we obtain after-the-fact. Since the development of mobile radars, there has been an increasing number of events whose EF-Scale ratings have been increased due to mobile radar data. These include:

The Calumet-El Reno-Piedmont-Guthrie Tornado of May 24, 2011

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: 4 ESE HINTON 3:50 PM CDT
EVENT END LOCATION AND TIME: 4 NE GUTHRIE 5:35 PM CDT
DAMAGE PATH LENGTH (IN MILES): 65 MILES
DAMAGE WIDTH: TO BE DETERMINED
NOTE: RATING BASED ON UNIVERSITY OF OKLAHOMA MOBILE DOPPLER RADAR
MEASUREMENTS.
---------------------------------------------------------------------------------------------

June 5 – Goshen County Tornado Given Official Rating of EF2

The Goshen County, Wyoming tornado of June 5th, 2009 has been given an official rating of EF2 on the Enhanced Fujita (EF) Scale, according to Meteorologist-in-Charge, John Eise of the National Weather Service Office in Cheyenne, Wyoming.
Preliminary wind measurements provided by the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX2) were added to the damage reports from the storm assessments on June 6th, 2009.  These two factors were considered in the new rating.

———————————————————————————————————————————–

And of course, I am biased towards using all data available to make a tornado estimate. I think it is silly to limit ourselves to the same methods used in the 1970s and ignore new technology when trying to advance the science. I do agree with others that suggest that mobile radar-based intensity estimates should begin to form their own database separate from the current damage database.

Now what about size?

WITH THIS INVESTIGATION... THE TORNADO HAS BEEN UPGRADED TO AN EF5
TORNADO BASED ON VELOCITY DATA FROM THE RESEARCH MOBILE RADAR DATA
FROM THE UNIVERSITY OF OKLAHOMA RAXPOL RADAR AND THE DOPPLER ON
WHEELS RADARS FROM THE CENTER FOR SEVERE WEATHER RESEARCH. IN
ADDITION... THE WIDTH OF TORNADO WAS MEASURED BY THE MOBILE RADAR
DATA TO BE 2.6 MILES AFTER THE TORNADO PASSED EAST OF US HIGHWAY 81
SOUTH OF EL RENO. THIS WIDTH IS THE WIDTH OF THE TORNADO ITSELF AND
DOES NOT INCLUDE THE DAMAGING STRAIGHT-LINE WINDS NEAR THE TORNADO AS
DETERMINED BY THE HIGH-RESOLUTION MOBILE RADAR DATA. THE 2.6 MILE
TORNADO PATH WIDTH IS BELIEVED TO BE THE WIDEST TORNADO ON RECORD
IN THE UNITED STATES.

Shouldn’t size be pretty straightforward? I mean, you can see the tornado.

Wakimoto et al.
Contoured Doppler velocity values overlaid on visual of the tornado at that time.

Whoa. Ok stay with me.

You can see the tornado here, right? It’s the tornado-looking thing in the middle, covered in squiggly lines. The squiggly lines are the mobile Doppler radar velocity estimates. That’s right, the same ones used to make the tornado intensity estimates. Anywhere you see those lines there is wind.

So what counts as the tornado winds? Well, so far it seems that the NWS has not been very consistent with its criteria for measuring size through mobile radar data. The El Reno statement from 2013 states that the “width is the width of the tornado itself,” which, I’ve heard from other sources, they used the EF-1 tornado minimum wind speed as the cut-off. Put in another way, how far out do the winds that are at least strong enough to count as an EF-1 go?

Should the NWS use only the EF-5 wind field for the El Reno tornado to estimate size? Probably not. People who lose property at a greater radius from the tornado center don’t care that they were “only” in the EF-4 or EF-3 winds. Should the cutoff be EF-3 winds? Does a tornado smaller than an EF-3 even get counted then? Even though we have better radar data than ever, there are still smoothing and averaging issues–how much variation are we missing at various levels of the tornado?

The El Reno size and intensity ratings sparked a lot of debate in the community, which has predictably died down over the past week. I know my colleagues still active in the research on this event will be presenting interesting data over the next few years on this storm, and I expect that this may cause the CSWR crew to pull out some size comparisons from their previous events.

And once someone figures out the “correct” answer to the tornado size question, let me know. I’ve been grasping at straws for a few years now.

Science Haikus (Scikus)

Too many ideas
Floating around in my head
I’ll haiku them all

Flooding closes schools
Way too much rain for the roads
Culpeper County

Weather is severe
Maryland had damage surveys
Five tornadoes here?

Such fearmongering
The media: “Derecho”
We shall wait and see

A moderate risk
Centered on Indiana
Prepare for the wind

My friends are out west
Collecting data on storms
I am stuck inside

I owe you a blog
On the El Reno twister
I’m sorry it’s late

The Business of Communication

I’m sitting at Ronald Reagan National Airport, waiting for my first work trip to start. I told my (then soon-to-be) supervisors during the interview process that I enjoy traveling, so my number came up for this trip…to Detroit. My more senior coworker went to Seattle earlier this month, and the other new guy went to Atlanta a week after that. I must have drawn the short straw.

Nonetheless, I’m interested in how this experience will go. I am well-rested from the weekend and have participated in enough meetings over the past three months at my company to anticipate at least a little excitement from this first visit with this lab. Scientists and business people collaborating—you know something awesome is going to happen. And it’s probably going to revolve around miscommunication.

I like to read relationship forums for the same reason I like to watch the Maury show—entertainment, first and foremost, but also the assurance that I’m doing better than somebody. I’ve yet to read a well-thought out answer on these forums with the response boiling down to more than, “Well, have you talked to him/her about it?” It’s a simple question, and the original poster always comes back with a defensive “of course!” Of course, if the couple had actually been conversing, not just talking, then one of them would probably not be asking anonymous internet strangers for help. (Or going on the Maury show, free trip to New York or not.)

Matt and I consider one of the strengths of our relationship to be our detailed level of communication. I think we both attribute a lot of this to the long-distance nature of our relationship, where we had to use our words to explain how we were feeling. When most people would kiss and make-up or go into separate rooms to fume, we were stuck, staring at each other on webcam. We couldn’t ignore our problems or the whole interaction would unravel. Thankfully, we both thought the other was worth fighting/conversing for.

The people I am meeting up with on this site visit I’ve only “met” in conference calls. I don’t even know what they look like. So far, we have only been able to rely on words (and screenshots) to convey our project. These face-to-face interactions are invaluable. My team is working on a Laboratory Information Management System (LIMS) to be used within the Food and Drug Administration (FDA) laboratories across the United States. It is supposed to harmonize synergies…or something. No really, despite all the business talk, it’s a good idea for the science. But the functional (scientist) and operational (program manager) sides don’t always understand one another. Often, the scientists in my company don’t understand the needs of the other scientists at individual sites.

I can hear the frustration on both sides of the phone call when a point of contention arises. Why didn’t you listen to us? We already told you all this. I’m just the notetaker, but for any in-person meetings I always have to stop myself from looking around at everyone in the room with a surprised “Did you just hear that?!” look on my face (what can I say? I watch Maury; I love me some drama). I’ve been very impressed with the business-y responses I’ve seen from the program management team, of which I am a part. I wish my thesis committee meetings had all gone so cordially! I used to make sure I was in the lab whenever Eric had a committee meeting, because it supplied my much-needed dose of drama for the day. I’d have Nathan and sometimes Eric’s wife on Gchat, ready to supply updates from the field.

Now, I’m working with the people whose job it is to keep everyone happy. I do not think it is in me to do that on a daily basis in the way my supervisors do, and, if I may generalize for a moment, I think the division between the heated scientists and the cool-minded business people is clear. And this is not just the FDA scientists; my company’s scientists can also get heated in a way the program management team does not, at least not in a group meeting. It was one of the first things that my Quality Assurance team brought to my attention in my meeting minutes: I use too many emotionally-charged words. My initial reaction was that what constitutes an emotionally-charged word is subjective in and of itself, and I nodded along as I was told that my choice of verbs was too opinionated for meeting minutes. It’s the nature of my writing, academic or otherwise, to try to tell a story, and I can follow the meeting better when it is written as:

Bob argued that the system needed the additional features, and Steve countered that the features would affect overall functionality.

Rather than:

Bob said that the system needed the additional features, and Steve said that the features would affect overall functionality.

Was Steve saying that as an aside to Bob’s point, agreeing with him? I don’t know, it just says “said,” so there is no flow.

Once I got over my pet writing preferences (ok I’m not really over them), I understood that the bigger picture was to not make anyone feel like they have been characterized incorrectly. I could poll all the attendees at the meeting and they could all say that Bob was definitely arguing, but Bob is going to become defensive at the wording in the account. So we use “said”…every…time.

We also want to appear unified as a company, so our minutes refer to the “Dovel Team” rather than to a particular individual answering questions. If a lab user wants to know if something is plausible, we don’t sit around arguing for half an hour about whether it is a dumb request, we make note of it, legitimately follow-up with the lab later, and in the meantime continue with the scheduled agenda.

But all the objectively-worded meeting minutes in the world will not take care of the fundamental issue of miscommunication. Conversations require a level of mutual respect and understanding among all parties involved, which I think already exists in these meetings. Once that criterion is met, there should be some active listening going on, ensuring that everyone understands each other before moving onto the next topic. And then no one feels misunderstood or ignored. Except for everyone on the Maury show.

STORM:CON, Naming Winter Storms, and Other Media Hype

A few months ago, The Weather Channel announced it would begin naming winter storms.  Today, it released a new winter storm severity index named STORM:CON.  The idea is similar to its summer TOR:CON, identifying tornado potential risk, although the latter is little more than an interpretation of the Storm Prediction Center’s severe weather outlook.

The idea of assigning unique identifiers to significant weather events is not a new one.  Most people are familiar with the naming of tropical storms; the World Meteorological Organization is responsible for the naming of the Atlantic events, and eastern hemispheric scientists take responsibility for their regions.  Personifying the storms with familiar names has allowed scientists and the media to make the general public aware of a specific storm and its expected human and ecological impacts.  Even the naming of winter storms is not uncommon; newscasters and reporters have been known to sensationalize blizzards under the headline “Snowmageddon” and Twitter hashtags like “#snOwMG.”  In the scientific community, local National Weather Service offices have assigned event names to significant lake effect snow storms and even tornadoes after the events.

What makes The Weather Channel’s approach to both names and numbers controversial?  The television network is promoting the idea as a way to raise public awareness of potentially hazardous snow events, a goal that most of the media and scientific community seem to encourage.  The primary concern of the community about this new approach is the unilateral power given to a private organization (The Weather Channel) in deciding which storms are named and ranked, and doing so with a very loose set of criteria.  Unlike the naming of tropical storms, which have very specific criteria to meet before being named, the channel has announced that storms will be named based on subjective measures like the population of a region being hit and the time of day that the storm affects an area.  Accordingly, a foot of snow dropped in the rural Appalachian mountains may not result in a named storm, but two inches of snow in a major metropolitan area occurring at rush hour may garner an identification.

From a scientific standpoint, both ideas are essentially useless without specific criteria based on a consensus from the community at large; from a media standpoint, there is no obligation for individual news outlets to use The Weather Channel’s naming or ranking conventions.  Many scientists consider the general idea of naming winter storms to be sound, but are concerned with the methods being employed here.  As was shown following the landfall of Hurricane Sandy (which evolved into a significant winter storm event of its own) very few in the media opted to utilize The Weather Channel’s naming convention for Winter Storm Athena, which followed two weeks later.

STORM:CON appears even less likely to be applied across various media outlets than the storm names, as is evidenced by the lack of universal usage of TOR:CON, which was released a few years ago.  The same problems that plague the haphazard naming of winter storms also plague this new index, as some level of subjectivity will be incorporated into the 1-10 ratings, which read as follows:

STORM:CON 1 to 3
Snow or ice occurs but does not produce significant impacts.

STORM:CON 4 to 5
Impacts would disrupt commerce or travel but not force closures.  You might see NWS advisories at this level.

STORM:CON 6 to 7
Impacts would close down commerce or travel for a day or less. Metro areas with active NWS Winter Storm Warnings might fit into this category. Recently named winter storms such as AthenaBrutusand Caesar would likely be in this category.

STORM:CON 8 to 9
Impacts would close down commerce/travel for multiple days, typically reserved for biggest storms which might occur 3 to 4 times a year.

STORM:CON 10

Reserved for anticipation of debilitating storms which might occur once or twice a year.  Complete shutdown of travel and commerce possibly for several days.  Examples would include storms such as Snowtober, Snowmageddon etc.

If The Weather Channel were to reach out to other meteorological organizations to achieve a consensus on naming and ranking storms, I (and others) would be less likely to label this as another example of media hype.  From my professional view, however, this comes off more as a quest for ratings than a quest for public awareness.

Formula for a Science Museum

This weekend, Matt and I went to the Science Center in Baltimore thanks to a nifty LivingSocial deal.  As Scientists(TM) and self-proclaimed nerds, we really enjoy playing around at museums.  We take somewhat different approaches to each exhibit, however: I read each posted sign or instruction (for hands-on exhibits), while Matt runs around touching things and speed-reading through various visuals.

I posted briefly about the Chicago Museum of Science and Industry on my last failed blog, and after our trip to Baltimore this weekend Matt and I realized our standards are now too high.  Chicago’s exhibits are top-notch and there is plenty of space for children to roam without getting too underfoot.  Baltimore’s exhibits followed the same tired pattern of every general science museum:

  • Our Bodies, Ourselves
  • Planets and Space
  • Flight
  • Earth and Nature
  • Dinosaurs
  • An IMAX theater
  • Science Store! (always my favorite exhibit)

Now the Baltimore museum did have a cool future energy-efficient cars exhibit, but from our travels it seems that is a new addition to the “must-have exhibits” in today’s science museums.  My favorite exhibit was the one with the least amount of children roaming about, a new study about race in the vein of “are we really all that different?”  We noticed that even though the exhibit was “new,” much of the data cited were from older studies, so even it seemed out-of-date.

The children seemed to enjoy themselves (which is most important), but after our Chicago experience, Matt and I left disappointed.  Chicago had the Bodyworks exhibit on display when we visited, which preserves real body parts so people can observe what they look like on the inside.  We were particularly impressed by the progression of fetuses (feti?) in various stages of development that had been preserved.  There was a baby chick hatchery with fresh chickens being born to a live audience, and there was a full-size train engine inside.  Even the food court was impressive.  Of course, we were also dazzled by the Science of Storms exhibit which included many of our friends and colleagues, as well as the IMAX dome showing of “Tornado Alley.”  We saw an IMAX film in Baltimore as well, but the screen was not a dome and the movie was made in the 1980’s.

Anyway, I think the take-home message is to support your local science museums, financially.  These places need the funds to update and maintain their exhibits–it could mean the difference between a two-story and a two-foot tornado simulator.