Bazaar
How Tornado Forecasting Changed Since 'Twister' | Weather.com
Advertisement
Advertisement

Weather Explainers

From 'Twister' To 'Twisters': How Tornado Forecasting, Technology Has Changed Since 1996

Play

Sign up for the Morning Brief email newsletter to get weekday updates from The Weather Channel and our meteorologists.

This summer's release of the movie "Twisters" may bring to mind how much has changed in the meteorology and technology of tornado forecasting and warnings since the original "Twister" came out 28 years ago.

D​irected by Lee Isaac Chung, this latest action thriller will arrive in theaters in the U.S. July 17, and stars Daisy Edgar-Jones and Glen Powell.

"​This is just a modern telling of that same community that audiences responded to in '96," Powell told Reuters, referring to the movie "Twister" released in 1996, as the new film was premiering in London.

L​et's take a trip down memory lane and revisit 1996.

T​echnology

An estimated 36 million were using the "world wide web" in 1996, the year after weather.com launched. In April 2024, almost 5.5 billion were online, or roughly two out of every three people on Earth.

I​t would also be another 11 years until Apple first unveiled the iPhone. So, no apps with radar, alerts or live streaming severe weather. Instead, the PalmPilot 100, a "personal digital assistant" was released, planting an early seed for what would eventually become the smartphone.

S​ocial media was also in its infancy. Instead of TikTok, Instagram, Snapchat, Facebook and X (formerly Twitter) serving up video and photos of tornadoes as they're happening, the world's first social networking site, "Six Degrees" was founded in 1996. It would be seven years before the first widely-used social network, MySpace, was launched.

(Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on our Premium Pro experience.)

People using their Palm hand held computer devices to exchange business cards at a computer conference.
People using their Palm hand held computer devices to exchange business cards at a computer conference.
(Getty Images)

F​orecasting

N​OAA's Storm Prediction Center (SPC) issues daily national forecasts of severe thunderstorms and coordinates with local National Weather Service offices to issue tornado and severe thunderstorm watches.

I​n 1996, they hadn't yet completed their move from Kansas City to Norman, Oklahoma, a move to increase collaboration with severe storm researchers in central Oklahoma.

At that time, SPC's outlooks were only issued for the current day (Day 1) and the next day (Day 2). In 2024, they're issued in detail for today, tomorrow and the next day (Day 3), and broad outlooks for the following five days are also issued to give an early heads up on potential outbreaks up to a week in advance.

Now heavily used today, ensemble forecasting - running the same computer model multiple times with slightly tweaked initial conditions - was just in its initial stages in the mid-1990s. And today's computer models specially tuned to thunderstorms - known as convection-allowing models or CAMs - weren't in a forecaster's toolbox in 1996.

(For even more granular weather data tracking in your area, view your 15-minute details forecast in our Premium Pro experience.)

An example of a convection-allowing model (CAM), the HRRR model, on July 10, 2024.
(Tropicaltidbits.com)

R​adar

T​he nationwide rollout of National Weather Service Doppler radars wasn't completed until 1997, the year after "Twister" debuted.

T​oday, not only do we have this national network that can detect rotation in severe thunderstorms, but we can also detect debris lofted by tornadoes, confirming their presence, even at night without spotters.

Advertisement

T​his so-called tornadic debris signature was made possible by a retrofitting all NWS radars from 2010 through 2013 with dual-polarization technology designed to pick up the shape of particles, not simply their size or wind motion.

N​WS Doppler radars are now also able to scan the lower levels of severe thunderstorms more frequently through a scanning strategy known as "SAILS". This allows forecasters to monitor for critical changes in severe thunderstorms, including identifying tornadoes faster.

A tornadic debris signature is seen in this radar image from a tornado that produced EF4 damage in Newnan, Georgia, on March 25, 2021.
(National Weather Service)

W​arnings

I​n 1996, tornado and severe thunderstorm warnings were largely issued by county. That often warned too many people for severe weather that may only have affected part of a county.

S​o, in 2007, the NWS rolled out "storm-based warnings": smaller, more focused warnings based on the storm, not the county it impacted. Researchers are working on a new paradigm for warnings, known as FACETs, that could continuously change with the storm.

Unlike in 1996, we also have different types of tornado warnings today. These range from warnings due to rotation seen above the ground that could produce a tornado, to the tornado emergency, when a life-threatening, potentially catastrophic tornado is ongoing, usually headed toward a town or city.

T​hat first "tornado emergency" was issued by the NWS-Norman, Oklahoma, office during the May 3, 1999 outbreak.

T​here are also higher-end warnings for severe thunderstorms - with at least baseball size hail or more destructive winds - and flash flood emergencies.​

Radar image and text of the nation's first "tornado emergency" NWS alert on May 3, 1999.
(NWS-Norman, Oklahoma)

Damage Surveys

We have also seen a change in the tornado damage scale since "Twister".

T​he original Fujita Scale, developed in 1971, rated tornadoes from F0 to F5. But as weather.com meteorologist Jonathan Belles explained in a previous article, there were shortcomings with that scale, including estimated wind speeds that were too high.

In 2007, after extensive study by a panel of meteorologists and engineers, the current Enhanced-Fujita (EF) scale was implemented, incorporating not simply damage from homes, but also barns, retail buildings, factories, high-rises, even transmission towers and trees among its 28 damage indicators.

A​s opposed to 1996, today's damage surveys can be done using drones to access hard-to-reach areas. Post-storm satellite imagery is also used today to either help confirm weaker, short-lived tornadoes or define their paths.

Kimberly Ergish holds flowers as she cleans out belongs from her tornado damaged home, Wednesday, May 22, 2024, in Greenfield, Iowa. (AP Photo/Charlie Neibergall)
Kimberly Ergish holds flowers as she cleans out belongs from her tornado damaged home, Wednesday, May 22, 2024, in Greenfield, Iowa.
(AP Photo/Charlie Neibergall)

W​hat Else Happened In Summer 1996

  • O​n July 18, 1996, the year's only F5 tornado tore like a drill bit through Oakfield, Wisconsin. Miraculously, nobody was killed.
  • America's only two landfalling hurricanes of the 1996 season each did so over North Carolina's Bald Head Island. Bertha did so as a Cat. 2 in mid-July, followed by Cat. 3 Fran on Sept. 5.
  • D​olly The Sheep, the first mammal to be successfully cloned from an adult cell, was born on July 5.
  • T​he Summer Olympics were held in Atlanta from mid-July through early August.

M​ORE ON WEATHER.COM

-​ How To Prepare For Severe Weather Like A Meteorologist

-​ 10 Tornado Myths Busted

-​ 15 Severe Weather Tips That Could Save Your Life

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. His lifelong love of meteorology began with a close encounter with a tornado as a child in Wisconsin. He completed a Bachelor's degree in physics at the University of Wisconsin-Madison, then a Master's degree working with dual-polarization radar and lightning data at Colorado State University. Extreme and bizarre weather are his favorite topics. Reach out to him on X (formerly Twitter), Threads, Facebook and Bluesky.

Advertisement
Hidden Weather Icon Masks
Hidden Weather Icon Symbols