An Interview with Tim Vasquez, Owner of Stormtrack: A Mesoscale Forecasting Expert Shares Reflections on the Past and Glimpses into the Future

Among the various weather-related forums extant today, Stormtrack has one of the longer—perhaps even the longest—track records. Not only so, but it also carries on a rich legacy begun in 1977 when pioneer storm chaser David Hoadley published the first Storm Track newsletter. The newsletter evolved into a magazine, the publishing torch passed on to veteran chaser Tim Marshall, and the print edition ultimately morphed into an online forum for chasers worldwide under the ownership of Tim Vasquez.

Like Stormtrack, Tim has a rich and varied background replete with experiences that range across the weather spectrum, from storm chasing to operational forecasting to education and more. From 1989 to 1998, Tim served as an Air Force meteorologist. As early as 1985, he developed weather analysis software tools, which eventually culminated in WeatherGraphix and Digital Atmosphere. He has also published a series of weather forecasting books, including Severe Storm Forecasting and the Weather Analysis and Forecasting Handbook. Tim’s resources and services—which include nowcasting and forecasting training for storm chasers—are available through his WeatherGraphics website.

Tim is obviously one very busy guy, not to mention one of the most recognized names in storm chasing circles. In this interview, he shares some fascinating, personal perspectives on storm chasing and mesoscale forecasting back in the day as well as today. Amid the cornucopia of forecasting tools and resources that are now available to chasers, it’s eye-opening to learn not only what existed over two decades ago, but also how determined and knowledgeable a person had to be in order to tap into it. And it’s exciting to consider some of the possibilities that the future has in store.

Enough of this introduction. I hope you’ll enjoy what follows.

Interview with Tim Vasquez

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Question: Owner of Stormtrack.org, the renowned, longstanding forum for storm chasers worldwide. Forecasting software developer, meteorological consultant, severe weather educator, author of a series of outstanding books on storm chasing and forecasting, professional nowcaster … you’ve covered pretty much every base there is, Tim, except for storm chasing tour guide. I don’t think anyone who’s been seriously involved in chasing for even a brief amount of time doesn’t recognize you as one of the gurus of operational forecasting.

In the midst of all that, one of the sides of you with which I think people are least familiar these days is who you are as a storm chaser. Yet unquestionably you’re an extremely seasoned chaser, one of the true veterans. So let’s talk about that part of you, beginning with how it all started. What first got you enamored with severe weather and tornadoes? Was there a defining moment, or moments, back in your formative years?

Tim: I would say the defining moment came in May 1985 when I was at the National Weather Service in Fort Worth. There were never any good forecasting books at the libraries and no Internet, and AMS publications were expensive. The NWS office there had a little reading room, so I used to go over there to sift through their technical library and page through their saved weather maps. One day while I was there, all hell broke loose in the Panhandle. The office didn’t have forecast responsibility in that area, but everyone was watching things closely with things like the Kavouras dial-up radars and phone calls.

That’s when I met Al Moller, whose enthusiasm was infectious. I was able to ask questions and follow what was going on without getting in the way. Another forecaster there gave me a regional surface map and invited me to analyze it.  After I was done, we all worked through my results. By the time I left that evening, Al had told me about Stormtrack and given me Tim Marshall’s phone number and also a small stack of NOAA tech memos, which he dug out of one of the offices.

That’s not to say I hadn’t had a similar experience, as I used to visit the weather station at Clark Air Base in the Philippines and learned the art of the skew-T there. But this particular NWS visit put me on the road to severe weather, chasing, and the art of mesoanalysis.

Q: How old were you when you went on your first storm chase? What were the circumstances and what was it like?

T: I was eighteen. I had spent an entire winter building up a severe weather library and wanted to get my feet wet on the very first slight-risk area of the year.

Unfortunately I was trying a bit too hard to build up credibility, so I did my chase under the guise of a small research project (me and a few friends, but mostly me). I even had a crude, instrumented TOTO box to place in front of an approaching tornado.

As you might suspect, this first chase was very early: mid-February. It was dark by 5:00 p.m., and a few hours later I was in a squall line south of Dallas. The only thing memorable that happened on that chase is that one of the spark plugs somehow came loose on an engine cylinder in my vehicle. I was out in the middle of nowhere, in the dark and the rain, and I puttered into an abandoned gas station. Fortunately, I had prepared for something like this thanks to Tim Marshall’s Texas Tech chase manual. In ten minutes, I fixed the problem and was heading home. That experience reinforced to me the value of carrying tools.

Sometime that year I also dropped the pretense of a chase team and just chased for the enjoyment and education. Many of my chases during the early years were with Glenn Robinson and Gene Rhoden.

Q: Today’s chasers have an incredible wealth of resources at their disposal. But you came up in a time when there was no Internet, no iPhones or laptops or GR3, no GPS, no HRRR or SREF, no computer-generated indices, none of the stuff that people today take for granted. Talk about how you went about forecasting and fining in a chase-day target back then.

T: Interestingly, back in the “old days,” the data was there if you knew how to be resourceful. A few of the dyed-in-the-wool hobbyists of the late 1970s, for example, took advantage of the era before telephone deregulation and were able to get the NOAA Weather Wire and even the same DIFAX feed that the NWS used.  Some of this was available for free on HF radio well into the 1980s, so with that and a one-hundred-pound fax machine which I managed to acquire for free, I was able to get basic model forecasts.

With computer modems, we did have a sort of pre-Internet experience. Hourly observations were not cheap, but I was able to get them from CompuServe or from a number of long-distance dialup sources. I have a huge binder of 1980s hand-plotted maps, but the drudgery of actually drawing the station plots was the main problem. And I saw what AFOS could do. This led me to develop several analysis programs for the Commodore 128 and later the PC (Digital Atmosphere by 1996) so that I could focus on the analysis.

The items we chronically lacked were raw upper air data, which could only be obtained from an expensive provider like Accu-Data; and satellite imagery, due to the sheer expense of adequate display technology. So I wasn’t able to practice the full range of mesoscale analysis techniques until 1989, when I started working in an actual weather station.

Q: When it comes to field experience, what were some of the things you learned early on about reading the sky, interpreting changing conditions, and, as Shane Adams has put it, “working a storm”?

T: Having a solid diagnosis of the atmosphere before you leave the house (or the motel room) is the key thing, because the atmosphere never plays out like you expect. By 11:00 a.m., you have to be completely grounded in what’s happening at the surface and aloft, not just at the target area but also throughout the entire region. There’s rarely any time or opportunity to figure it out all over again once you’re out there.

Also I learned that I can be the one to fill in the gaps in the diagnosis by stopping regularly to take a measurement—not to write in a logbook, but rather to make sure that the winds and moisture are in the ballpark of what I expect them to be.  There have been several times when I thought I was at a good spot along the dryline, but once I dragged out the sling psychrometer, I found the dewpoint to be something like 57 or 58 and wound up repositioning back to the east. Today’s mobile weather stations are excellent for this kind of thing, but visually reading the character of the sky and matching that up to your expectations from the morning diagnosis is still an essential skill.

Once near a storm, I found map-reading and positional awareness to be critical skills. Certainly anyone who’s chased along the Canadian or Red Rivers can attest to this. You not only need to be in the right location, but you also have to make sure you have a way out in case your navigation plan doesn’t work out. Having a good GPS display or a good map reader in the passenger seat is essential.

Q: Describe one or two of your most outstanding chase experiences.

T: Most of the 2000s put me at the desk running the Chase Hotline or helping to take care of my son, who was born in 2003, so a lot of my actual field experiences draw from the 1990s. The historical May 3, 1999, outbreak is definitely near the top. I chased with Gene Rhoden that day. I still have a memorable impression of watching the birth and growth of the storm that would later devastate parts of Oklahoma City. It soon produced tornadoes, but we lost it due to the road network. Then we joined with the Anadarko storm and saw a highly visible, eerie nighttime tornado near Dover.

Another outstanding chase experience that comes to mind is memorable in a different way. This was also in May 1999, I think May 16. I had targeted Crowell, Texas, and I drove the five hours there from Oklahoma City, arriving just in time to adjust westward and catch a tornado coming off the Caprock before it shrank and roped out. It was an average chase success, but in the passenger seat was my soon-to-be-wife, Shannon, on her fifth chase; and in the back was her lifelong best friend, Kathryn, who had just flown up from Houston hoping to see what a storm chase was like. It ended up being the first time either of them had seen a tornado. So this was a fantastic experience for us all, and the nighttime lightning display heading back home was just phenomenal.

Q: Nowadays, major chase days are characterized by a blizzard of live streams and a glut of Spotter Network icons on the radar screen. But you’re nowhere to be found in that mix. That seems to be the case with quite a few veteran chasers. My sense of it is, you want to chase in peace without having a bunch of tag-alongs intrude on your experience. How often do you actually make it out into the field to chase these days? When you head out, what do you seek in terms of the quality of your chase? How would you say your values and approach differ from those of younger chasers?

T: For a fortunate few, storm chasing will be a constant, lifelong activity. But work, school, and family are there too. All of us at one time or another have to deal with things like tightened budgets, a new baby, a new job away from the Plains, medical problems, family problems, car problems, new meteorological passions, new interests, and so on. They’ve caused many veterans to fade from sight, and I’ve dealt with some of those things myself.

But even if I’m not in the field, I’m following the chase day. I have an insatiable passion for forecasting. Who needs Sudoku and crosswords? A meteorological diagnosis is a tremendously awesome and dynamic puzzle, and I feel like I have a brain that not only specializes in unraveling these puzzles but has a kind of dopaminergic reaction to solving them. And there’s so much remote sensing data coming online, in terms of surface data, MADIS, profilers, satellite imagery, WSR-88D data, and now the new dual-polarization radars. I really feel like a kid in a candy store on a storm day, and I have to say I’d feel kind of disconnected being out in the field. It’s not really the end result that I want to see, but the underlying machinery.

So I think that the mesoscale aspect of the chase day, rather than the chase itself, is my calling. That’s not to say that I’m done with chasing. Our needy baby has grown up into a bright and independent kid, the Chase Hotline demands have abated, we’re back in Norman, and I’m always looking at the sky and taking weather photographs. Plus, I’m responsible for Stormtrack. So I probably will be out there again as early as this month. I have an iPad, so maybe I’ll get linked up with one of the networks, too.

Q: What excites you, and what concerns you, about the state of storm chasing today? How do you see it evolving in the next five or ten years?

T: The Internet is making an enormous impact. Ten years ago it simply gave us a way to share pictures and messages and helped to pipe data to our forecast desk. Today it’s providing a two-way street from the world to the storm base. It’s reaching out to more and more mobile devices and extending further into remote regions of the Great Plains. As a result, we’re already seeing a sort of fusion of spotting and chasing and another real-time channel in the warning process.

Furthermore, the Internet is global, so someone in Mongolia or Madagascar can share in the thrill of a tornado developing over empty rangeland near Dalhart as it happens. That’s mind-blowing.

Another development I’m expecting is growth in international chasing. Very few people have any idea of the significance of east India and Bangladesh’s supercells; I think they’re easily comparable to some of the storms we have on the Great Plains. The largest CAPE values I’ve ever seen have always been on the Calcutta soundings. That region is gradually improving its road network and mobile Internet, and real-time data options are just now coming into existence there.  The only limits, of course, are chase budgets and haze.

Back here in the United States, we’re certain to see new advances in forecasting with the new dual-polarization radar upgrades, and as we get experience with these radars and the body of scientific literature grows, I expect that warnings will become even better and that chasers will increasingly find themselves on the “right” storm. Those last fifty miles of the chase are still as critical as they were in 1980.

Q: If you could share three tips or words of advice with contemporary chasers, what would they be?

T: As follows:

  • Chasing: Hydroplaning and nighttime obstacles are the things that have put me in danger more than anything else. I’ve had a lot of close calls with cows basking on the road and downed power lines stretching across lanes. At 60 mph, there’s only a few seconds to react before your destiny either brings you home or into an obituary on Stormtrack.

    • .

  • Forecasting: Diagnose the atmosphere—not necessarily hand-analyze, but sift through all of the observational charts and products before even looking at models. As humans, we tend to develop a bias in the first bits of evidence we see, so if we start with observed data, we bias our forecasts according to what’s actually happening in the atmosphere. My books and classes go into a lot of this.

    • .

  • Community: Support Stormtrack and help our beginners. Over the past couple of years, we’ve seen a fragmentation of the entire chaser community across the social media spheres—Twitter, Facebook, and so forth—which is not an ideal situation. The Stormtrack forum has always been the singular resource for promoting smart, safe, and cooperative chasing. Chasers are welcome to get their start elsewhere, if they wish, but if that happens, I worry there’ll be more anonymity out in the field and more unsafe behavior.

Q: When can we look for Mr. T’s next forecasting workshop in Stormtrack?

T: He’s down in Altus trying to get all the kids to stay in school. I’ll drag him out of there and maybe we’ll get one out this spring.

April 5, 2012 by
Filed Under: Guest Posts and Interviews, Software & Technology, Storm Chasing, Tornadoes, Weather Tagged With: , , , , , ,

Book Review: Weather Analysis and Forecasting Handbook by Tim Vasquez

I initially became acquainted with Tim Vasquez’s books a good ten or so years ago at my very first severe weather conference at the College of DuPage. Tim was sitting at a table selling, among other things, his Weather Forecasting Handbook. I bought a copy and began chewing on it, and I have continued to do so ever since over the years. There’s a lot of essential information packed into the 204 pages of the old “Purple Book.” (Tim’s books are known colloquially by the color of their covers.)

That book took me deeper into a world of meteorological concepts that I was only beginning to become aware of, ones that storm chasers need to know. My brain not being the kind that readily absorbs such stuff by reading alone, it took me a long time and many read-throughs to grasp some of the arcane principles, language, and tools that are integral to making one’s own forecasts and selecting target areas. I still have a few things to learn–okay, plenty of things–but much of the material Tim covered is now familiar to me, and I apply it regularly.

Ragged and torn from long use, my old copy of Tim’s book sits beside me now as I write. Next to it is a brand-new copy of its heir-apparent, the Weather Analysis and Forecasting Handbook.

While anyone familiar with the old book will recognize much of the material, the new Purple Book is far more than just a makeover. At 260 pages, it provides considerably more information, all of it reflecting current research and technology. This is weather forecasting as it is today, not as it was a decade ago. Indeed, so much new material has been introduced; so much of the pre-existing text has been revised and expanded; the illustrations have been updated and extended to such a degree; and the content has been so thoroughly reorganized overall, with an eye on taking the reader beyond concepts to analysis and forecasting, that the Weather Analysis and Forecasting Handbook is for all intents and purposes a new book, not just an updated edition. And, I might add–and I say this rather grudgingly, having cut my teeth on the old handbook–this new volume is a more comprehensive and helpful resource than its venerable predecessor. There is just a lot more to this book, and it’s all presented in a well-thought-out fashion.

Main Content

One significant change in the Weather Analysis and Forecasting Handbook is the organization of its content. As does the previous book, this one begins by introducing foundational physical concepts such as mass, force, pressure, temperature, the Coriolis force, geostrophic wind, vorticity, and so forth.

The second chapter on observation also appears largely familiar, though it keeps abreast of current practices. However, the previous treatment of clouds is only lightly addressed because the subject is given an entire section of its own in the book’s appendices.

Beginning with chapter three, the changes become pronounced. Here is a very abbreviated overview of the book’s structure from this point:

Chapter three: Thermodynamics–Deals with instability and familiarizes the reader with atmospheric soundings. Here is where you’ll learn how to read and interpret that essential forecasting tool, the skew-T/log-P diagram.

Chapter four: Upper Air Analysis–Taking a top-down approach to forecasting, this chapter introduces constant pressure charts, long waves and short waves, divergence and convergence, jets and jet streaks, and other atmospheric processes and influences from 100 mb down to 925 mb.

Notably missing is a structured introduction to charts for specific pressure levels, such as the 500 mb height map. That discussion has been shifted to the appendices. Instead, chapter three focuses on the various factors that the maps depict, and the book makes such liberal use of the different maps by way of illustration that the reader gains familiarity with them through osmosis. My guess is, Tim believes that by helping readers understand upper-air dynamics and processes, the significance and use of the various maps will become apparent through real-world examples.

Chapter five: Surface Analysis–Learn how to read a surface chart, get a basic grasp of air masses, and discover the importance of various boundaries, from cold and warm fronts to drylines and outflow boundaries.

Chapter six: Weather Systems–This chapter groups together concepts from several chapters in the old forecasting handbook. The presentation is logical and fresh. Subjects covered include all-important baroclinic lows and highs, barotropic systems, arctic air outbreaks, and winter weather systems.

Chapters seven and eight deal, respectively, with satellite and radar. Suffice it to say that they are required reading. Since both remote-sensing tools are visual in nature, plenty of pictures are provided to illustrate patterns, systems, outflow boundaries, velocity aliasing, severe weather signatures, and so on.

I’m a bit surprised to see not a single screen grab of a velocity couplet, either in the radar chapter or in the ensuing chapter nine on convective weather. However, velocity products rely highly on a full-color format and don’t lend themselves easily to this book’s black-and-white images. Tim points this out later in figure 9-6, where he writes, “Typical NEXRAD color schemes do not reproduce well in monochrome books.”

Importantly, the chapter on radar discusses the new dual-polarization technology that is being implemented nationwide at the time of this review. Dual-pole is a huge development in the NEXRAD system, probably the biggest stride forward since the deployment of NEXRAD itself.

Chapter nine: Convective Weather–For aspiring storm chasers, this chapter will likely be the Holy Grail of the book. Besides dealing with the ins and outs of thunderstorms, from single-cells to supercells to mesoscale convective systems, this chapter discusses storm-relative winds and introduces another indispensable forecasting tool, the hodograph. Chapter nine moves on to talk about tropical systems including hurricanes.

Chapter ten: Prognosis–This last chapter in the main body of the book deals with the actual process of forecasting. Readers will at this point have recognized that Tim is a strong advocate for understanding not merely how the atmosphere is likely to behave, and where, and when, but also why. Here he discusses the four-part forecasting process. He emphasizes the importance of a hands-on approach to analysis while at the same time recognizing the key role of numerical models, the application, strengths, and weaknesses of which he discusses at length. The chapter concludes with a brief overview of ENSO and teleconnection patterns.

The entire book is amply illustrated. Barely a page exists that doesn’t include some kind of black-and-white chart, map, or photograph. These visual supplements are clear and immensely helpful, to the extent of being integral to understanding much of the written content.

To round things out, the book is peppered with sidebar commentary ranging from the informative, to the philosophical, to the historical, to the humorous. For instance, on page 31 I find a table of NATO color codes; page 57 furnishes a thumbnail discussion of long waves; a lengthy entry on page 120 describes five different empirical forecast techniques; and on page 166, there’s a wry commentary on how to tell whether a tornado is forming using the “thumb tab” approach of the Field Guide to North American Weather.

Appendices

This section is an informational gold mine. Strangely, it’s not even mentioned in the table of contents, so I’m going to give you the breakdown here:

Appendix one: Forecaster’s Guide to Cloud Types–Photos and descriptions of major cloud types, including brief discussions of each one’s significance from a forecasting standpoint.

Appendix two: Surface Station Plots–What all those numbers and symbols mean.

Appendix three: Surface Chart Analysis Procedures–Brief guidelines for doing surface analyses.

Appendix four: Upper Air Station Plots–Similar to the second appendix, except applied to upper air plots.

Appendix five: Upper Air Chart Analysis Procedures–This is about as close to an overview of specific pressure maps as this book provides, which it does from an analysis perspective. This appendix divides into three short sections on upper-, middle-, and lower-tropospheric charts. Between them, they provide insights on the significance, use, and analysis of upper-air maps from 100 millibars all the way down to 925 millibars.

Appendix six: An Isoplething Tutorial–Veteran forecasters invariably are strong advocates of hand analysis, and Tim is a prime example This appendix shows you how to get started at creating your own hand-analyzed weather maps.

Appendix seven: Conversions and Symbols.

Appendix eight: Instability Index Summaries–Brief discussions of the more commonly used forecasting indices such as CAPE, CINH, lifted indices, the energy-helicity index, and the SWEAT index. A couple of these tools–BRN shear and storm-relative helicity–aren’t in themselves related to instability; however they’re so widely used in severe weather forecasting that they require discussion, particularly since they’re factored into such true instability indices as the EHI, STP, and Bulk Richardson Number.

Appendix nine: Types of Thermodynamic Diagrams–Brief discussions and graphic examples of the skew-T/log-P, emagram, Stuve, pastagram, aerogram, and tephigram.

Appendix ten: Blank Diagrams–Reproducible blank skew-T and hodograph.

Appendix eleven: Observation Format Overview–For the incredibly geekish, a quick reference guide to the most commonly used weather-reporting formats: METAR, SYNOP, and TEMP (radiosonde code).

Additional appendix materials without assigned section numbers include the following: suggested reading, software, educational websites, government weather agency websites, and top-ten weather myths.

Three Recommendations


Let me preface my following few critiques by saying that this is a fantastic book. The author is both a veteran storm chaser and an educator, and that combination has inspired him to create a practical resource that is both accessible to lay-persons and helpful to operational forecasters. Storm chasers and anyone who wants to develop skill at weather forecasting would do well to put it in their library.

This said, I have three comments that Tim may wish to consider at some point:

• I liked the old handbook’s quick, specific introductions to the 200/250/300 mb, 500 mb, 700 mb, 850 mb, and surface charts. The overviews of those charts gave me–at a time when I was a complete novice and needed weather knowledge delivered to me in brick form–an instant, systematized reference to the constant-pressure maps that are such essential tools of the trade.

Granted, entire books have been written about weather maps, including Tim’s own Green Book, the Weather Map Handbook. The new Weather Analysis and Forecasting Handbook is obviously not intended to fill such a role. But perhaps in the appendix section, the fifth appendix could be fleshed out a bit by providing a top-down sampling of CONUS maps for a single date/time. That way those unfamiliar with upper atmospheric maps could see how, say, March 13, 2011, at 1200 UTC mapped out at 300 mbs, 500 mbs, 700 mbs, 850 mbs, 925 mbs, and on the surface.

• Granted the limitations of trying to translate something as color-dependent as radar velocity products into a gray-scale format, there may nevertheless be a benefit to making the attempt. I say this because the ability to recognize storm-relative velocity couplets is so critical in storm chasing. While the illustrations on page 145 (figs. 8-2a–f) do a good job of conveying the general idea, there’s nothing like real-life examples. Perhaps such examples could be included in the future, whether directly in the book or possibly as a link to a page featuring radar screen captures on Tim’s Weather Graphics website.

• A quick, easy-reference glossary of essential terms would be a welcome addition.

With these three suggestions on the table for Tim to consider in his next edition, I unhesitatingly recommend this book. It’s superb, a labor of love by one of the gurus of operational forecasting who clearly cares a great deal about helping others learn the ropes.

Some months back, I reviewed Tim’s other recent publication, Severe Storm Forecasting. It’s another excellent resource for storm chasers in particular, covering some of the same ground as this book and expanding considerably on the subject covered in chapter nine, “Convective Weather.” Good as that book is, though, Weather Analysis and Forecasting provides the more complete, well-rounded picture. Be forewarned: it’s not a book you will read and absorb in one sitting. It is chewy material that will require you to approach it analytically and patiently. This is a resource you will pull off the shelf again and again, whether to re-engage with material you’re still trying to grasp or to refresh yourself on concepts you’re already familiar with.

Purchasing Information

  • Weather Forecasting and Analysis by Tim Vasquez, 260 pages.
  • $29.95 plus shipping, available from Weather Graphics.

NOTE: This is a non-paid review. I’ve written it as a service to my readers and to Tim because, having read the book, I’m convinced of its value for storm chasers and severe weather buffs.

February 7, 2012 by
Filed Under: Opinion & Editorial, Reviews, Storm Chasing, Weather Tagged With: , , , , , , , , , , , ,