National Weather Service United States Department of Commerce

Tracking Two Storms Crossing the U.S. with Rain, Snow and Gusty Winds

A storm gathering strength over Texas today will shift to the Mid-Atlantic through Tuesday night. Areas of freezing rain and heavy snow will spread from the central Plains east into the Mid-Atlantic and southern New England. Further south, areas of severe thunderstorms and heavy rain are possible from the southern Plains into the Ohio Valley. A Pacific storm will move into the Southwest Monday. Read More >


by Don Burgess, National Severe Storm Laboratory [Ret.]


Ingredients for a devastating severe weather event were beginning to come together on the morning of April 10. At the surface, an already strong low pressure area in southeast Colorado was beginning to deepen further, and a warm front was starting to lift northward from central Texas. To the south of the warm front, moist, unstable air was streaming northward. In the upper atmosphere, the nose of an extremely strong jet stream wind maximum was moving eastward through northern Mexico, preparing to turn northeastward and take aim on Texas and Oklahoma.

By afternoon, the warm front had lifted to the vicinity of the Red River, and a new low pressure area had formed near Childress. A dry line had formed from the Childress low southward, and temperatures had become very warm in west Texas. Aloft, the strong wind maximum was over the Red River area, producing significant vertical wind shear. Severe, tornado-producing, thunderstorms erupted along the dry line and moved eastward along and north of the warm front, continuing into the night in central and northeast Oklahoma.

After dark, another jet stream wind maximum moved northeastward into west central and northern Texas, sparking a second round of severe thunderstorms and tornadoes. The night time tornadoes, although strong, were not as devastating as the ones that occurred in the Red River Valley during the afternoon. Overall, the outbreak produced nearly 30 tornadoes and a large number of damaging wind and severe hail reports.


The Red River Valley Tornado Outbreak


Three isolated supercells, forming in mid afternoon, moved northeastward as a trio and were responsible for the worst part of the outbreak. The northern supercell, the Vernon-Lawton storm, produced its first tornado at 1505 CST (3:05 PM) south of Crowell, TX. About 1540 CST (3:40 PM), a tornado devastated the southeastern portion of Vernon, TX (11 fatalities). Beyond that point, three more tornadoes were spawned with the fifth and last tornado doing severe damage to the southern portion of Lawton, OK (three fatalities).

The middle supercell, the Harrold-Grandfield storm, produced the longest-track tornado of the outbreak (64 mile path length) at 1555 CST (3:55 PM). A Doppler radar view of the three supercells is available. Fortunately, the strong and wide Harrold-Grandfield tornado spent its entire life in rural areas not striking any towns, but coming close to Harrold, TX (one fatality) and Grandfield, OK.

The southern supercell, the Wichita Falls storm, produced its first tornado at 1653 CST (4:53 PM) near Seymour, TX. The storm's second tornado, the terrible Wichita Falls tornado, formed at 1755 CST (5:55 PM) to the southwest of the city and moved through the southern and eastern sides of Wichita Falls shortly after 1800 CST (6:00 PM). The tornado finally ended near Waurika, OK after traveling 47 miles. The Wichita Falls storm produced a third and final tornado about 2000 CST (8:00 PM) near Pruitt, OK.


The Wichita Falls Storm


The Wichita Falls storm formed north of Abilene, TX. It generally moved to the northeast, but turned to the right along the middle of its path, the period during which it produced its violent tornado. During its life, radar-derived storm tops exceeded 50,000 feet and reflectivities were higher than 50 dBZ. It is interesting to note that the Seymour and Wichita Falls tornadoes both formed during periods of relative decline in storm-top height and reflectivity values, a characteristic that has been noted for a number of supercell storms that have produced several cycles of tornadoes. In particular, note the sharp decline in reflectivity near the genesis time and during the life of the Wichita Falls tornado with maximum values less than 45 dBZ for a brief period. During this period, large hail was occurring in the central and northern portions of Wichita Falls as the tornado devastated the southern portion of the city. No explanation for the unusually low reflectivity values with that phase of the storm (sensed by several radars) has been developed.

The Norman Doppler radar was used to collect dense data (0.5o azimuth spacing and 150 meter gate spacing) on the Wichita Falls storm during the interval leading to the formation of the violent tornado. At 1730 CST (5:30 PM), a core of greater than 50 dBZ and two mesocyclones were seen with the storm. The northeastern mesocyclone in the mesocyclone pair was the occluding parent circulation of the Seymour tornado while the southwestern mesocyclone in the pair was the developing parent circulation of the Wichita Falls tornado. By 1800 CST (6:00 PM), the storm had taken on a very classic supercell look with the tornado-associated mesocyclone and hook echo in the right rear portion of the echo. Note that the 50 dBZ core was no longer evident.


The Wichita Falls Tornado


The Wichita Falls tornado formed several miles southwest of the city in Archer County, and traveled over mostly open terrain. With an east-northeast movement, it entered Wichita County and damaged a few rural homes and a string of metal high-voltage towers. Moving into the city, the tornado first struck Memorial Stadium and McNiel Junior High School (location #1 on the damage path diagram), severely damaging both structures.

The formation of the tornado and its movement toward the stadium and junior high were captured by Wolfgang Lange from the front of his apartment complex which was located across the street from the junior high (location #2). After taking his last picture of the approaching tornado, Mr. Lange retreated to the apartment complex laundry room and hid between heavy commercial washers and dryers, escaping with only minor injuries. On the first street of houses to the northeast of Lange's apartment complex, Robert Molet also photographed the approaching tornado (location #3).

Unlike Mr. Lange, Mr. Molet did not have an unobstructed view of the western horizon and did not immediately recognize that the threatening cloud was a tornado. Thus, he stood in his backyard driveway and photographed the destruction of the apartment complex and the beginning of destruction in his neighborhood. Mr. Molet continued to take photographs until the wind blew him into his garage. Although his house was completely destroyed, Mr. Molet escaped with only minor injuries as his pickup truck was blown over him, protecting him from the worst winds and debris.

The tornado's first fatalities were recorded in the apartment complex and adjoining housing area. Continuing east-northeast, the tornado severely damaged commercial building along Southwest Parkway, including total destruction of the Southwest National Bank Building except for its vault (location #4). To the north of Southwest Parkway, the tornado destroyed many houses in the Western Hills Addition. Further eastward, most houses in the Faith Village Addition were destroyed, and Ben Milam Elementary School was severely damaged (location #6). The tornado was photographed from the south during this period by Pat Blacklock location #5). In the latter Blacklock photographs, the gust front and associated strong west winds to the south of the tornado can be seen producing waves on Lake Wichita and kicking up spray from the lake.

As the tornado crossed Kemp Boulevard., several commercial businesses, including a restaurant, were destroyed with several additional fatalities. The tornado's worst winds generally missed the Sikes Senter Shopping Mall to the South, but a few of the stores were heavily damaged and many cars in the mall parking lot were blown some distance and stacked on top of each other. Beyond the shopping mall, the tornado crossed a greenbelt area, skirted Midwestern State University on its south side, and severely damaged several more housing additions (Colonial Park, Hursh, Southmoor, Southwinds, and Southern Hills). During this interval, the tornado was photographed by Professor Joe Henderson of Midwestern State University from the Ligon Coliseum (location #7). The tornado was also captured on film by Troy Glover from the roof of the Bethania hospital (location #8).

A number of people tried the flee from the tornado as it crossed the south side of the city by getting in cars and driving east on Southwest Parkway, north on US Highway 281 and east again on US Highway 287. The tornado blew many of those vehicles off those roadways, inflicting numerous fatalities. There were a total 42 tornado fatalities in Wichita Falls, of which 25 were vehicle related. Sixteen of the 25 got in vehicles to evade the tornado, and 11 of the 16 homes which were left did not incur damage by the tornado. Before leaving the east side of the city, the tornado destroyed the Sun Valley housing area, the Sunnyside Heights Mobile Home Park, and several large commercial businesses, including the Levi Strauss Plant.

Northeast of Wichita Falls, the tornado entered Clay County and changed its appearance. As seen in the photographs by Winston Wells (location #10), the tornado became multi-vortex, displaying as many as five satellite vortices rotating around the center of circulation. In this stage, the tornado did extensive damage just south of Dean and near Byars, destroying a large number of rural homes, but causing no more fatalities

The suffering and destruction caused by the Wichita Falls tornado is nearly inconceivable. The passage of a violent tornado through an 8-mile section of a city is an almost unheard-of natural disaster. In addition to the 42 fatalities directly caused by the tornado, three more people died of heart attacks and other illnesses during the stress of the tornado's passage. The number of reported injuries approached 1,800 although hundreds of additional minor injuries were never recorded

Total property damage in Wichita Falls was estimated at $400,000,000 (in 1979 dollars). Over 3,000 homes were destroyed and another 1,000 were damaged, and over 1,000 apartment units/ condominiums were destroyed and another 130 damaged. In addition, approximately 140 mobile homes were destroyed, two schools were demolished and 11 others sustained serious damage. Over 100 commercial businesses, some of them large manufacturing concerns, were destroyed. It is estimated that 5,000 families, containing 20,000 residents, were left homeless in Wichita Falls. Such a total would mean that between 10% and 20% of the population of the city was displaced by the tornado. To put the deaths and property damage in perspective, it should be noted that as many as 42 people have not been killed in the United States by a single tornado in the 20 years since the event, and the total property damage of $400,000,000 still stands as the most costly tornado in American history.


F-Scale of the Wichita Falls Tornado


After the tornado, a thorough investigation of the damage was performed by Texas Tech University, Institute for Disaster Research, and the University of Chicago. Dr. Ted Fujita of the University of Chicago used these surveys to estimate the F-scale and probable wind speeds associated with the tornado. A detailed mapping of each house and public/commercial building in the city led to the construction of an F-scale map. Damage as severe as F4 was found along most of the track across the city. One somewhat unique characteristic of the damage was the wide swath F4 damage; many violent tornadoes produce only a narrow swath of their most intense damage. The width of the F4 damage in the Wichita Falls tornado approached 0.5 miles in the area of Faith Village and Ben Milam Elementary School (location #6).

The wide swath of damage can also be seen by viewing the NASA aerial photographs (aerial photos 1-10 on the Wichita Falls damage page) and the other aerial photographs (photos 7 & 8 on the Wichita Falls damage page). The width of the F1 damage was generally as wide as one mile, and the extent of the F0 damage was even wider, but so widespread that it was not mapped. Strong inflow winds associated with the tornado and the larger-scale mesocyclonic winds rotating around the tornado produced light damage over almost all of the city.

There was much scientific discussion and debate concerning the possibility that the some of the damage was severe enough, and wind speeds high enough, for the tornado to be rated F5. The two worst damage points appeared to be McNiel Junior High (location #1 on the damage path diagram; photos 9-15 on the Wichita Falls damage page) and the Southwest National Bank (location #4; no close-up photographs available). After extensive engineering analysis of the winds necessary to produce the observed structural failure to those buildings, it was concluded that all of the damage could have been produced by winds in the upper part of the F4 range (230 - 260 mph). Thus, the tornado damage/intensity was officially rated as a strong F4 tornado.


Lessons to be Learned from the Wichita Falls Tornado


1. Tornado warning and preparedness systems are worth the time and effort it takes to maintain them. All who have looked at and studied the event agree that the death toll would have been much larger had there not been not been such systems in place and functioning on April 10.

2. Vehicles (cars, pickups, and trucks) are poor protection and should be avoided during tornado situations in larger cities where travel is congested and tornado escape routes are not readily available and open for use. The majority of the fatalities were in vehicles, and a number of those victims left homes that were undamaged by the tornado only to be caught in its deadly path as they tried to flee.

3. Well-built modern houses, in general, offer fairly good protection from tornadoes. Some or all of the walls remained for well-built homes (photos 4-6 on the Wichita Falls damage page) and bathrooms in particular provided good protection. Although roughly 4,000 homes were struck by the tornado, there were only five fatalities of people inside homes along the path of the tornado. Many of the 1,800 injured, however, were in homes. This means that those people who moved to the center part of their houses, got down low, and covered themselves, by-in-large escaped with their lives, sustaining injuries instead of death.

4. Even though lesson #3 (above) is true in a violent tornado, the only complete guarantee of safety comes from an underground shelter, an above-ground shelter, or an extremely strongly-built building. McNiel Junior High, a new concrete/steel-reinforced building was not built well enough to provide safe shelter from the tornado. The Southwest National Bank Building was totally destroyed except for its concrete vault, a proxy for an above-ground shelter.

5. As bad as the tornado was, it could have been worse. If McNiel Junior High had been fully occupied by students and teachers at the time of the tornado, there would have been hundreds of additional casualties and many more deaths. Very large groups of people gathered in tornado-vulnerable places, such as schools, stadiums (such as Memorial Stadium), and outdoor events, are disasters waiting to happen. Every year in the United States the threat of a catastrophe looms whenever tornadoes approach large gatherings of people. Fortunately, on April 10, 1979, McNiel Junior High was almost totally unoccupied when the tornado struck and a worse catastrophe was avoided.