The 1970 Lubbock Tornado

May 11, 2020, marks the 50th anniversary of the most tragic event in our city’s history, the 1970 Lubbock tornado. The tornado caused extensive damage to the northeast side of Lubbock and resulted in the loss of 26 lives, over 1,500 injured, and approximately 250 million dollars worth of damage (in 1970 dollars), equivalent to about 1.7 billion dollars in 2020. The tornado was rated an F5 on the  Fujita Tornado Damage Scale , which is the highest a tornado can be rated. No known photographs were taken of the tornado, which is mainly attributed to the facts that the storm occurred after the sun had set and before the age of digital photography.

As devastating as this fateful event was, it served as a turning point for future development and it paved the way for advances in tornado and wind engineering research. Scientific works in these fields continue right here in Lubbock and at Texas Tech University today.

At 4:00 AM that morning, the Severe Local Storms (SELS) unit of the National Severe Storms Forecast Center (NSSFC) in Kansas City, MO issued an outlook that kept West Texas clear of severe storms over the next 24-hours. This outlook was upgraded at 10:00 AM to add "also isolated thunderstorms with large hail expected on the High Plains of West Texas east of Pecos during the late afternoon or early evening."

• 8:15 PM - The first Tornado Warning Bulletin of the night is issued by Alan Johnson, Warning Forecaster, for Lubbock, western Crosby, Eastern Hale and Floyd Counties until 9 PM. The LBB WSR-1 radar did show a hook formation in the same area of the reported funnel cloud.
• 8:40 PM - Severe Thunderstorm Watch issued for all of the South Plains until 2 AM

8:59 PM - A second Tornado Warning Bulletin was issued for Lubbock, western Crosby, eastern Hale and Floyd Counties.

• 9:34 PM - Until now, only hail damage had been reported across the area.

• 9:49 PM - Lubbock WBO lost all communications
• 10:00 PM - Lubbock WBO abandoned (Amarillo office took over radar and warnings) to shelter from approaching tornado
• ~10:03 PM - The tornado lifts and passes as a funnel over the WBO on the east side of the Lubbock Airport. The winds were still so fierce that a large crack developed in the wall of the Bureau office.
• 10:08 PM - Lubbock WBO takes control back from Amarillo, continuing to deliver warnings via 2-way radio relay through the Fire Department.
• 11:30 PM - All tornado warnings cancelled

• Dr. Tetsya "Ted" Fujita and the F-Scale

The study of the meteorological data from May 11, 1970, in combination with an extensive damage survey completed in Lubbock of the aftermath, helped, in part, in the development of the Fujita Tornado Damage Scale (F-scale) in 1971 by Dr. Fujita. The F-scale was the de facto standard used to rank tornadoes by the amount of damage that they inflict, until it was revised in 2007.

The study of the damage patterns, especially from overhead with aerial photos, allowed Dr. Fujita to further develop his theory that some tornadoes contained more than one vortex (i.e., there were multiple vortex tornadoes). This was evident with the Lubbock tornado, where swaths of extreme damage were located immediately adjacent to locations of very light damage, all within the tornado path itself (see the aerial photograph to the left).

• The National Wind Institute

The tornado was used as inspiration and justification for the establishment of the Wind Science and Engineering (WISE) Research Center at Texas Tech University in 1970, which later became the  National Wind Institute  (NWI) in 2012. The NWI became famous for its Debris Impact Facility, which could simulate the impact that flying objects such as wooden two-by-fours had on structures. The NWI has developed voluminous information on windstorm mitigation and other wind-related subjects that are available to professionals and public alike. The NWI center has brought many professionals, much money, and tremendous recognition to the South Plains.

• The EF Scale

Texas Tech University and the National Wind Institute also become key partners with the National Weather Service and other entities in revising the F-Scale. The new, Enhanced Fujita, or EF Scale, was adopted in 2007. It more accurately aligned the estimates of wind speed with the latest research on wind-induced structure damage. For more information on the EF Scale, please visit this website at the  Storm Prediction Center .

The thunderstorm that spawned the Lubbock tornado was rare in that it formed on a retreating dryline. The dryline is a narrow boundary between dry continental air to the west and moist air from the Gulf of Mexico to the east. It is often present across the High Plains of the U.S. during the springtime and is especially common in the South Plains of West Texas. When there is not a strong storm system bringing winds that will overwhelm the dryline, the dryline will move east (advance) during the day as the air heats up and then will move back to the west (retreat) during the evening. While thunderstorms often form along advancing drylines during the afternoon and can produce large hail and even tornadoes, thunderstorms that form along retreating drylines are much less frequent, and only rarely produce tornadoes. This is due in part to the air becoming more stable (air temperature decreases less rapidly with height) as the air cools near the ground after the sun sets.

The figures below show the atmospheric conditions that existed leading up to and during the Lubbock tornado. These are common maps that meteorologists use to examine the state of the atmosphere. In the 1970s, weather balloons were the primary means to collect information from the atmosphere above ground level.

The following slide shows shows the 250 mb, 500 mb, 700 mb and 850 mb constant-pressure charts from 7 am Monday Morning (12 UTC 11 May 1970).

Tracking the Dryline: The next series of three weather maps follow the progress of the dryline from the late afternoon to the evening of May 11, 1970. The dryline initially made its way east of Lubbock during the early afternoon, with winds shifting from south to west and dewpoints, which are a measure of the moisture in the air, dropping from lower 60s at 10 am CDT to mid 30s by 1 pm.  Click here  to view the hourly observations taken at the Lubbock Airport on May 10, 11, and 12, 1970.

However, as the 4 pm surface map and observations show, the winds quickly switched back around to the south at the airport, preventing the moisture and dryline from advancing far from Lubbock. Although surface observations in West Texas were sparse in 1970, they did manage to pinpoint the area of confluence (air coming together) associated with the dryline to be located between Reese AFB, with a light west wind and the Lubbock airport, with a south wind. Temperatures had also warmed nicely, under sunny skies, into the lower and middle 90s.

Three hours later, at 7 pm, the surface map continued to depict the dryline, and related confluence, between Reese AFB and the Lubbock airport. This extended period of confluence near Lubbock aided in the development of clouds and eventually thunderstorms as the warm and increasingly moist air that was coming together at the surface was forced to rise. Additionally, the 7 pm observation at the airport indicated that cumulonimbus clouds, which are dense, vertically developed clouds that produce thunderstorms, were visible to the south and distant northeast of the airport. The surface map indicates the approximate locations that the isolated thunderstorms had developed.

Finally, the 10 pm surface map reveals that the dryline had continued its retreat more rapidly off to the west, with moisture and southeast winds returning to southeast New Mexico, Reese AFB, and Amarillo. The thunderstorms that were developing at 7 pm were now mature, feeding off of abundant low-level moisture supplied by strong southeast winds.

A sounding is a vertical profile of the atmosphere obtained by a weather balloon; measuring temperature, moisture and wind speed and direction. Meteorologists use these soundings to evaluate how conducive the atmosphere is to the development of thunderstorms, and whether or not the storms will be capable of producing severe weather, like hail and tornadoes. Soundings are usually performed twice a day; in the morning and evening. In 1970, the nearest soundings to Lubbock were launched at Amarillo, Midland and Abilene. Given that there was no actual sounding near to the time and location of the Lubbock tornado, there is some uncertainty in what the atmospheric profile actually looked like, and there is some educated guesswork involved.

In the slideshow below, the first two images show the observed soundings at Midland taken in the morning and evening of 11 May. Storms developed in the Midland area several hours before the Lubbock storms, and outflow winds from the storms near Midland may have enhanced the retreating dryline in the Lubbock area. The third sounding is our best estimate of the thermodynamic profile at Lubbock around the time of the severe weather (roughly 9 pm). However, some of the fine-scale details of the atmosphere in the area will never be fully known.

The series of negative images to the left taken from the Amarillo radar depict what meteorologists in Amarillo would have seen on their radar scope on the night of May 11. The radar, located in Amarillo, is centered in the middle of the range rings toward the top left-hand side of each image. Lubbock is located almost due south of Amarillo on the fourth range ring (second range ring on the images where the range rings are less dense). The dark "blobs" are radar returns, or radar echoes.

The series of images show no radar echoes at 6 pm. The first storm starts off as a small radar echo south and southwest of Lubbock. Over time, this echo grows as it slowly moves off to the north and east. Then, at both 8:30 and 9 pm, the largest radar echo, located over the city of Lubbock, is associated with the first tornado that touches down on the east side of town (the location of the first tornado is plotted with a dot at both times).

The thunderstorm over Lubbock continues to build over the city from 9 to 10:30 pm as it merges with smaller echoes that approach and get absorbed into the massive storm from the south and southwest. The location of the second more destructive tornado is plotted with a dot on the 9:45 and 10 pm images. After 10:30 pm, the storms generally decrease in areal coverage and organization as they move off to the east and northeast.

As seen from the above images, the Amarillo radar perspective was helpful in identifying storm location, but less helpful in seeing the details of the storm, primarily because the radar was located so far away. Although not pictured here, radar images as seen from the radars located at Reese AFB and the Lubbock airport both depicted greater detail of the storm, which aided in the issuance of timely warnings. In particular, both nearby radars detected a hook shaped radar echo (known as a hook echo), which is a feature that is sometimes produced by a rotating storm, and can be a signature associated with the development or presence of a tornado.

The map below shows the locations of 25 of the 26 victims. The 26th victim, Shelbey Curtis Glenn, 29, of Idalou Texas, is not included on the map because the location was not recorded. The victims ages ranged from 9 months old to 88 years old. A family of four died at 2301 Mesa Road, and four fatalities occurred close together at the intersection of Loop 289 and Interstate 27.

The following map was created using images taken from shortly after the tornado, put side-by-side with recent photographs taken in the same locations.

The population of Lubbock was about 150,000 in 1970. The population has grown to over 230,000 in the 2010 census and is estimated to exceed 260,000 in 2020. In addition, enrollment at Texas Tech University was about 20,000 in 1970, and has since grown to over 36,000 in 2017. Needless to say, given the growth in population and traffic, a tornado of similar size and intensity would have the potential to cause far greater damage and casualties today. The slideshow of maps below describe how we took the original tornado track map developed by Dr. Fujita, and overlaid it on a aerial map of Lubbock from 2019. Using GIS, we determined over 75,000 residents could be affected by the tornado (not including motorists). If the tornado tracked over the more densely populated portions of southwest Lubbock, the number of residents affected could rise over 100,000.

• 3.25 inches of precipitation was reported at the airport from all the rain and hail received
• The large, destructive tornado, was 1 1/2 miles wide early on, before narrowing to about 1/4 mile wide by the time it reached the airport.
• 10,000 automobiles were damaged or destroyed
• 119 aircraft were demolished at the airport
• Area of the tornado damage covered 15 square miles.
• 600 apartment units were demolished, 250 businesses damaged or destroyed
• 8,800 family units damaged, of which 430 were destroyed
• In downtown Lubbock, an estimated 80% of all plate glass windows were smashed

• Texas Tech Southwest Collections Archive information on the Lubbock Tornado:  https://southwestcollection.wordpress.com/2014/05/12/the-lubbock-tornado-may-11-1970/ 
• Lubbock Avalanche-Journal 1970 Tornado Web page:  https://www.lubbockonline.com/1970tornado 
• Tornado Information from the Storm Prediction Center (SPC):  https://www.spc.noaa.gov/faq/tornado/ 
• Severe Storm Information from the National Severe Storms Laboratory (NSSL):  https://www.nssl.noaa.gov/education/svrwx101/ 

• "The Lubbock, Texas, Tornado May 11, 1970". Natural Disaster Survey Report 70-1. July 1970.
• "The Lubbock Tornadoes: A Study of Suction Spots". Weatherwise. August 1970.
• "The Lubbock Tornado". Boone Publications, Inc., 1970
• Some photographs are courtesy of the Southwest Collection/Special Collections Library, Texas tech University, Lubbock, Texas and the City of Lubbock