Coming Soon: An Update to the Definitive Book on U.S. Tornadoes

November 30, 2023, 5:00 PM EST

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Above:  Damage from an F4 tornado that tore through the heart of Omaha, Nebraska, on Easter Sunday 1913 (March 23). It was part of the worst tornado outbreak on record for eastern Nebraska and western Iowa. Close to 100 deaths were reported in Omaha, with some 2000 structures destroyed. Image credit: NET.

The creator of the de facto bible of U.S. tornado history and climatology is on a mission, and it’s a big one. Independent researcher Thomas Grazulis has embarked on a major update of his magnum opus: the 1340-page Significant Tornadoes 1680-1991. The update, which will extend through 2019 this mammoth census of all known U.S. tornadoes rated at least F2/EF2, is already sparking excitement among storm enthusiasts, researchers, and print-book lovers.

Long out of print, Significant Tornadoes 1680-1991 was available at last check from a third-party seller on for a cool $634.11. The book’s only supplement to date, covering the period 1992-1995, could be acquired for $4 used or $526.09 new.

Published in 1993, just before the rise of the Internet, Significant Tornadoes 1680-1991 could have been a simple database. As a print volume, though, it’s compulsively browsable, and it has a heft and authority that befits the meticulous work Grazulis has carried out since 1970. To produce the book, Grazulis pored through a variety of sources–including more than 10,000 microfilm newspaper reels at more than 100 libraries across 41 states—in order to piece together and verify details on thousands of twisters that predate the official NOAA/NWS Storm Prediction Center database, which goes back to 1950. In all, the book documents 12,209 tornadoes.

For each tornado listed, Grazulis provides the states and counties affected, starting time, path length and width, and the number of direct deaths and injuries. Each tornado also gets a description—as little as several words (“destroyed one barn”) or as much as several paragraphs. The book also includes 51 tornado photos taken before 1970, which he says represents the largest such collection on Earth.

Some of the details assigned by Grazulis for post-1950 tornadoes differ from those in the official SPC database, including the F-scale ratings of about 2200 tornadoes. This isn’t too surprising, he said, given that the original ratings for many tornadoes from 1950 to 1971 were calculated by more than 200 people, including many undergraduate students. “It is far easier to improve on someone else’s work than to create that original body of data in the first place,” Grazulis wrote in the book’s preface. “Counting and measuring tornadoes seems as if it would be a rather simple chore. However, it is as difficult and challenging a task as any in meteorology.”

Among many themes that emerged while writing Significant Tornadoes, Grazulis confirmed that the death tolls from many Southern tornadoes into the early 1900s had been underestimated because only the names of white victims were typically printed in newspapers. “This racial aspect of tornado documentation was common until the late 1940s, and occasionally present, in some form, until the mid-1950s,” Grazulis said.

Tom Grazulis at desk
Figure 1. In one of four work areas devoted to the forthcoming revision of Significant Tornadoes, Tom Grazulis scrutinizes background materials for Volume 1, which will include a section focusing on tornadoes and climate change. Image credit: Doris Grazulis.

A career that won’t quit

Although he has never been employed directly by NOAA or a university, Grazulis is one of the world’s most knowledgeable experts on tornado climatology. Like the famed researcher Howard Bluestein (University of Oklahoma), Grazulis was profoundly influenced in childhood by his proximity to the disastrous Worcester, Massachusetts, tornado of June 9, 1953, which killed 94 people and injured almost 1300 along its 46-mile path. Grazulis believes Worcester was probably an F5, although it is officially ranked as an F4 by SPC.

In the early 1970s, Grazulis collected early tornado footage to create the world’s first compilation film, “Approaching the Unapproachable.” He then embarked on years of tornado climatology research in the 1970s and 1980s for the Nuclear Regulatory Commission and the National Science Foundation, a task that laid what proved to be groundwork for Significant Tornadoes. Along the way, Grazulis collaborated with some of the field’s most eminent figures, including Tetusya “Ted” Fujita (University of Chicago), who co-developed the Fujita intensity scale with Allen Pearson.

The first incarnation of “Significant Tornadoes” covered the period 1880-1989. That book sold so well that Grazulis was able to produce the more comprehensive 1680-1991 version. Grazulis and his company, The Tornado Project, also put together “Tornado Video Classics,” a three-volume set of VHS videos (later DVDs) based on the world’s largest collection of historical tornado footage. Thoughtfully edited and narrated, “Tornado Video Classics” set the bar high for comprehensive, science-based tornado documentaries in the 1990s, when VHS shelves were increasingly stuffed with often-exploitative “xtreme” videos.

At a time when many of their peers are in their second decade of retirement, Grazulis and his wife and research partner Doris are in the midst of a five-year commitment to the book update.

I asked Tom Grazulis to tell us more about the new book and why he’s embarking on it now.

BH:  Let’s cut to the chase. How big will the new book be?

TG:  If you’re adding almost 30 more years of tornado information—descriptions from 1992 to 2019—you’re in serious trouble with the size of the book. So we’re splitting it into two volumes. They’ll be about 750 pages each. We plan to put the project on Kickstarter in 2021. I expect the price to be about $160. It will probably go up another $100 after the Kickstarter campaign.

BH:  Why did you decide to wait till now to launch an update?

TG:  There were constant changes in how tornadoes were being documented [including the introduction of the Enhanced Fujita Scale in 2007]. I just had to wait until things settled down.

I wasn’t just interested in updating. I could have put that online. The first part of the book is going to be all about climate change. I’m convinced of two things: one, tornado activity is being influenced by climate change, and two, I can find hints on how and provide ideas that others can run with. The first thing you’ve got to do is get a decent database. You cannot determine this by simply counting the number of tornadoes. The human influence—chasers and technology—is overwhelming. The only way you could do it is by examining the intensity and the path length of each tornado.

BH:  What are your initial thoughts on climate change and tornadoes?

TG:  I’m absolutely convinced that climate change is affecting tornado activity—but in what way? The nature of the beast and the database is such that it’s an almost impossible question to answer. I’m almost constantly coming up with different conclusions.

I’m going through every single path length prior to 1970. Why then? At some point you have to determine when tornadoes started to be affected by climate change. On Twitter I’ve been posting pre- and post-1950 analyses, using my own database compared with the official database. I’ve also been looking at examples of variability, when tornado activity goes extremely high and extremely low. We’re in a drought of intense tornado activity right now.  Disastrous years like 2011 followed by quiet periods like now—what’s up?

Mockup of cover for forthcoming update to
Figure 2. Cover mock-ups for the two volumes of the forthcoming Significant Tornadoes 1680-2019. Both photos on the cover of Vol. 1 are from F5 tornadoes in Wichita Falls, Texas: (top) April 3, 1964, and (bottom) April 10, 1979. "The cover of Volume II has photos that are more personal," says Grazulis. At top right is a shot by Aaron Rigsby of the twin EF4 tornadoes that occurred near Pilger, Nebraska, on June 16, 2014. Grazulis notes: "The two tornadoes crossed paths. Many old newspapers told of tornadoes on the plains with huge multiple funnels and complex movements." The bottom right photo—"of a good friend, by a good friend"—depicts Tim Samaras (left) and Carl Young with a tornado near Storm Lake, Iowa, on June 11, 2004. Samaras and Young were killed in the El Reno tornado on May 31, 2013 (see our post from last Thursday), and geographer Dr. Matt Biddle, who took the photo, died in Oklahoma City on April 10, 2018, after a long illness. Image credit: Courtesy Tom Grazulis. See the Tornado Project website for more background on these images.

BH:  How were you influenced by working with Ted Fujita? At one point you were both carrying out tornado-related work for the Nuclear Regulatory Commission.

We developed a very good friendship. I’d go to the University of Chicago and we’d go to lunch. I’d ask him what should I do to make a proper judgment as I worked my way back to [examining tornado reports from] the Louisiana swamps in 1900. He helped me a lot. When I disagreed with him, he would ask graduate students to leave the room. He’d then explain how my thought processes were bad and how I needed to correct my thoughts.

Fujita thought that computer analysis ignored important outliers. His philosophy was “do it by hand!”, and that’s what I’m doing. I have a computer file that shows all SPC path lengths. Now I have to look at every one and see if it’s valid. Ted convinced me that you can’t just take a computerized database and draw conclusions from it. You’ve got to understand every single outlier and every single trend. You have to look at every point.

Fujita also taught me about self-publishing. He put out more than 200 publications through the University of Chicago. He didn’t bother with peer review on those—he just had an idea and he went with it. I’m not looking for any peer review on this book. I’m just hoping in the first five chapters to present these new ideas—about path length, week-by-week changes in the season, and how 1970 may be the transition year for climate change effects.

BH:  How much interest in the new book have you seen thus far?
TG:  We’ve got several hundred people from Twitter (@sigtor2019) who are definitely interested in making it worthwhile, and about 100 people from a Gmail account ( I’m constructing a Q&A to answer all the people who have sent an email.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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Bob Henson

Bob Henson is a meteorologist and writer at, where he co-produces the Category 6 news site at Weather Underground. He spent many years at the National Center for Atmospheric Research and is the author of “The Thinking Person’s Guide to Climate Change” and “Weather on the Air: A History of Broadcast Meteorology.”

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