1975 Omaha tornado outbreak
41°15′N 96°00′W / 41.25°N 96°W
| Type | Tornado outbreak |
|---|---|
| Duration | May 6–7, 1975 |
| Tornadoes confirmed | 36 |
| Max. rating1 | F4 tornado |
| Duration of tornado outbreak2 | ~2½ days |
| Fatalities | 3 fatalities, 137+ injuries |
| Damage | $250-300 million [1975 USD] |
| Areas affected | Midwestern and Southern United States |
| 1Most severe tornado damage; see Fujita scale 2Time from first tornado to last tornado | |
The 1975 Omaha tornado was a violent tornado that hit the Omaha metropolitan area in the U.S. state of Nebraska. It was the costliest and most powerful tornado out of 36 that touched down across the Midwest and South during the two-day outbreak. Besides Nebraska, South Dakota, Iowa, Texas Mississippi, and Louisiana were all affected by multiple tornadoes which resulted in millions of dollars [USD] in damages.
Meteorological synopsis[edit]
The tornado outbreak was associated with an intense area of low pressure that moved from Colorado into South Dakota beneath a strong upper-tropospheric trough. The combination of the low-pressure system and a ridge of high pressure over the Great Lakes moved unstable air in the lower levels of the troposphere towards eastern Nebraska.[1] At 7 a.m. CST on May 6, the area of low-pressure was centered over southwestern South Dakota, with a central air pressure of 991 mbar (hPa; 29.26 inHg). A cold front extended from the low-pressure southwestward to central Kansas, demarcating the boundary between a moist and warmer airmass to the east and a dry and cooler airmass to the west. Ahead of the cold front over eastern Kansas and Nebraska, dew points were near 65 °F (18 °C) while they were below 20 °F (−7 °C) behind the cold front over western Kansas.[2] An ongoing scientific field campaign run by NASA – Atmospheric Variability Experiments – sampled environmental conditions throughout the southwestern and southern United States during the eventual severe weather event.[3][4] A weather balloon launched from Omaha, Nebraska, at 7 a.m. sampled atmospheric conditions moderately conducive to severe weather.[5] During the morning hours, the broader wind pattern brought increasingly moist air in the lower troposphere over a narrow region encompassing eastern Nebraska, eastern Kansas, and northern Missouri.[6] This corridor of moist air was bounded to the west by the cold front and to the east by a warm front, each slowly moving.[7] Warmer and drier air persisted in the mid-levels of the troposphere above this moist air, resulting in conditions potentially favorable for the development of storms.[8] Daytime heating and the increase in moisture with time within this narrow region, as well as a simultaneous divergence of air in the upper-troposphere, further increased atmospheric instability, producing increasingly favorable conditions for storm formation.[9] Ahead of the warm front, thunderstorms and cloud cover over southern Iowa and northern and central Missouri caused cooler conditions ahead of the warm front, reinforcing a strong temperature gradient across the front.[10] This further enhanced the favorability of atmospheric conditions for storm development.[11]
The National Severe Storms Forecast Center (NSSFC) issued a tornado watch for much of the area in advance of the event at 12:37 p.m. CST May 6.[1][12] The watch area was in effect from 2–8 p.m. CST and encompassed parts of eastern Nebraska, northeastern Kansas, northwestern Missouri, western Iowa, southeastern South Dakota, and southwestern Minnesota.[12][13] The first indications of storm development were apparent in South Dakota by 11 a.m.[14] A squall line soon developed along the cold front, with the strongest thunderstorms occurring near the intersection between the cold and warm fronts ahead of the low-pressure area and along the warm front, including the storm that eventually produced a destructive tornado in Omaha.[8][10] Within this area, vorticity and convergence of winds near the surface were higher than surrounding areas.[15] The squall line was first apparent on weather radar at around 1 p.m. CST, extending from central South Dakota to central Oklahoma.[16] Between around 2–7 p.m. CST, the squall line produced several damaging tornadoes in northeastern Nebraska.[16] In the Omaha area, the development of thunderstorms was preceded by the movement of a comma-shaped area of cloudiness into the region, an indication of the movement of vorticity in the mid- to upper-troposphere into the region.[5] Many of the thunderstorms that produced tornadoes showed rapid growth on satellite imagery around the time of tornado development, indicative of the rapid rise of air.[17] The thunderstorms were supported by the channel of moist air, tracking north before eventually weakening after moving into cooler and drier air downwind.[10] Twelve tornadoes ultimately occurred over the north-central Great Plains on May 6,[1] with large and strong tornadoes affecting eastern Nebraska.[18] All but one of the tornadoes had relatively short tracks, with their parent thunderstorms moving across the narrow corridor of moist air and the steep temperature gradient accompanying the warm front; the storm that produced the long-track tornado moved parallel to the temperature gradient.[19] The same weather system led to at least 19 tornadoes on May 7, including 10 in South Dakota and Iowa.[1]
Confirmed tornadoes[edit]
| FU | F0 | F1 | F2 | F3 | F4 | F5 | Total |
|---|---|---|---|---|---|---|---|
| 0 | 11 | 6 | 14 | 3 | 2 | 0 | 36 |
May 6 event[edit]
| F# | Location | County | Time (UTC) | Path length | Damage | |
|---|---|---|---|---|---|---|
| South Dakota | ||||||
| F0 | SW of Kimball | Brule | 1705 | 12.4 miles (20.0 km) | Barns and farm structures were destroyed on 4 separate farms. Five cattle were killed. | |
| F1 | SW of Tabor | Bon Homme | 1946 | 0.1 miles (0.16 km) | Two barns were destroyed and a farmhouse was partially unroofed. | |
| F0 | SW of Tripp | Bon Homme | 2010 | 0.1 miles (0.16 km) | ||
| Nebraska | ||||||
| F4 | N of Pierce | Pierce | 1905 | 4.1 miles (6.6 km) | Tornado struck the town of Magnet, damaging or destroying every building in town. Homes were leveled, cattle were killed, and vehicles were thrown over 200 yards and destroyed. Remarkably, only one person was injured. | |
| F3 | E of Pierce to W of Menominee | Pierce, Cedar, Knox | 1915 | 44.8 miles (72.1 km) | Tornado destroyed barns and trailers and killed livestock. Homes and vehicles were damaged on the west side of Pierce. | |
| F0 | SW of Bloomfield | Knox | 1930 | 5.4 miles (8.7 km) | ||
| F3 | N of Stanton | Stanton, Wayne | 1945 | 15.9 miles (25.6 km) | ||
| F0 | SE of Colon | Saunders | 2100 | 3.4 miles (5.5 km) | ||
| F0 | S of Waterbury | Dixon | 2130 | 3 miles (4.8 km) | ||
| F4 | Omaha area | Sarpy, Douglas | 2133 | 8 miles (13 km) | 3 deaths – See section on this tornado | |
| Iowa | ||||||
| F2 | NE of Crescent | Pottawattamie, Harrison | 2200 | 12.8 miles (20.6 km) | ||
| F2 | W of Beebeetown | Pottawattamie, Harrison | 2220 | 10.6 miles (17.1 km) | ||
| Source: Tornado History Project - Storm Data for May 6, 1975, Grazulis (1975) | ||||||
May 7 event[edit]
| F# | Location | County | Time (UTC) | Path length | Damage | |
|---|---|---|---|---|---|---|
| Mississippi | ||||||
| F3 | W of New Hope | Lowndes | 1145 | 0.2 miles (0.32 km) | Trees down and light house damage. | |
| F0 | Biloxi area | Harrison | 1710 | 0.2 miles (0.32 km) | Sign twisted. | |
| F2 | NE of Smyrna | Copiah | 1750 | 9.7 miles (15.6 km) | ||
| F1 | S of Eaton | Forrest, Jones | 1930 | 5.4 miles (8.7 km) | Struck the town of Providence, where two homes were unroofed, and another was badly damaged. Many trees were downed, some of which landed on houses and roads. Two chicken houses were destroyed as well. | |
| South Dakota | ||||||
| F0 | N of Manchester to SE of Caprey | Kingsbury | 1655 | 0.1 miles (0.16 km) | ||
| F1 | E of Wendte | Stanley | 1800 | 0.1 miles (0.16 km) | ||
| F0 | W of Onida | Sully | 1955 | 0.1 miles (0.16 km) | ||
| F0 | SW of Onida | Sully | 2130 | 0.1 miles (0.16 km) | ||
| F0 | N of Mission Ridge | Sully | 2220 | 0.1 miles (0.16 km) | ||
| Texas | ||||||
| F2 | NE of Kingsland | Travis | 2200 | 0.1 miles (0.16 km) | ||
| F1 | N of Leander | Williamson | 2300 | 1 mile (1.6 km) | ||
| F2 | NW of Nolanville | Bell | 2300 | 0.1 miles (0.16 km) | ||
| Iowa | ||||||
| F2 | SE of Manteno | Crawford | 2330 | 0.1 miles (0.16 km) | ||
| F2 | NW of Jacksonville | Shelby | 0000 | 9.9 miles (15.9 km) | ||
| F0 | Creston area | Union | 0015 | 0.1 miles (0.16 km) | ||
| F2 | SW of Van Wert | Decatur | 0100 | 0.1 miles (0.16 km) | A barn and two hog houses were destroyed. | |
| F2 | Osceola area | Clarke | 0130 | 10 miles (16 km) | Six farms were damaged in the area, where barns and sheds were destroyed. The roof and doors were ripped from one house. | |
| Louisiana | ||||||
| F2 | W of Clare | Sabine | 0400 | 0.1 miles (0.16 km) | ||
| F2 | Welsh area | Jefferson Davis Parish | 0605 | 1 mile (1.6 km) | Four trailers and 6 homes were destroyed. One trailer was found deposited in a treetop. Many trees were snapped and uprooted and 3 people were injured. | |
| F1 | Mansfield area | De Soto | 0615 | 0.7 miles (1.1 km) | ||
| F2 | SW of Estherwood | Acadia | 0700 | 0.5 miles (0.80 km) | ||
| F1 | S of Duson | Lafayette | 0730 | 0.5 miles (0.80 km) | ||
| F2 | Baton Rouge | East Baton Rouge | 0730 | 6.2 miles (10.0 km) | ||
| F2 | NW of Jack | St. Helena | 0800 (05/08) | 0.1 miles (0.16 km) | ||
| Source: Tornado History Project - Storm Data for May 7, 1975, Tornado History Project - Storm Data for May 8, 1975, Grazulis (1975), | ||||||
Omaha, Nebraska[edit]
| F4 tornado | |
|---|---|
| Max. rating1 | F4 tornado |
| Fatalities | 3 fatalities, 133 injuries |
| Damage | $250-300 million [USD 1975] or $1.402-1.683 billion [USD 2023] |
| 1Most severe tornado damage; see Fujita scale | |
During the early afternoon of Tuesday, May 6, 1975, a tornado watch was issued for much of eastern Nebraska. Initial tornado activity started in northeast Nebraska throughout the first half of the afternoon. At around 4:15 PM, a tornado warning was issued for the Omaha area and an F4 tornado[20] touched down about 15 minutes later in Sarpy County, Nebraska. The storm then moved north-east, cutting into Douglas County crossing Interstate 80 (injuring several motorists) and through west-central sections of the city of Omaha. The tornado chopped a path across 10 miles (16 km) of streets and residences, crossing the city's busiest intersection at 72nd & Dodge. Extensive damage occurred along 72nd Street, with numerous homes and apartments severely damaged, along with Creighton Prep School and the United Methodist Church. The Westgate subdivision was devastated, with many homes leveled, and a few that were swept away. The nearby Westgate Elementary School was destroyed. Bergan Mercy Hospital, Lewis and Clark Junior High School, a motel, and several industrial buildings were severely damaged as well. The tornado later lifted in the Benson Park area at 4:58.[21]
In one remarkable instance, First United Methodist Church minister of music Mel Olson spotted the rolling clouds in the sky outside the windows of the room where he was rehearsing a children's choir. He led them to safety below the church building. The building, located at 70th and Cass Streets, was struck and heavily damaged by the twister. The room where the children had been practicing, with three walls of windows, was hit and the glass exploded.
Three people were killed and 133 others were injured. One of the fatalities was a woman who was thrown by the tornado from her home to a backyard four or five houses away.[22] At least 287 buildings were destroyed, and nearly 4,000 buildings were damaged with debris found, in some cases, several miles away. When adjusted for inflation, this remains one of the costliest tornadoes in United States history.
See also[edit]
References[edit]
- ^ a b c d Ostby & Pearson 1975, p. 19.
- ^ Moore & Elkins 1985, p. 41.
- ^ Hill & Turner 1977, p. 171.
- ^ Fuelberg 1979, p. 18.
- ^ a b Peslen 1979, p. 8.
- ^ Moore & Elkins 1985, p. 43.
- ^ Moore & Elkins 1985, pp. 43–44.
- ^ a b Moore & Elkins 1985, p. 44.
- ^ Moore & Elkins 1985, pp. 45.
- ^ a b c Maddox, Hoxit & Chappell 1979, p. 26.
- ^ Miller 1979, pp. 85–86.
- ^ a b NWS Central Region 1975, p. 1.
- ^ NWS Central Region 1975, p. B1.
- ^ Peslen 1980, p. 1410.
- ^ Maddox, Hoxit & Chappell 1980, p. 329.
- ^ a b Chang, Perkey & Kreitzberg 1981, p. 1601.
- ^ Adler & Fenn 1979, p. 516.
- ^ Dewey & Mogil 2017, p. 18.
- ^ Maddox, Hoxit & Chappell 1980, p. 327.
- ^ NWS Storm Summary and Damage Survey - May 1975 Omaha Tornado
- ^ "Damage Photos from the '75 Omaha Tornado". NWS Omaha. NWS Omaha. Retrieved 9 October 2013.
- ^ "Omaha 5/6/75". Archived from the original on 2008-02-19. Retrieved 2008-02-27.
Sources[edit]
- Adler, Robert F.; Fenn, Douglas D. (April 1979). "Thunderstorm Intensity as Determined from Satellite Data". Journal of Applied Meteorology. 18 (4): 502–517. doi:10.1175/1520-0450(1979)018<0502:TIADFS>2.0.CO;2.
{{cite journal}}: CS1 maint: ref duplicates default (link) - Chang, C. B.; Perkey, D. J.; Kreitzberg, C. W. (August 1981). "A Numerical Case Study of the Squall Line of 6 May 1975". Journal of the Atmospheric Sciences. 38 (8): 1601–1615. doi:10.1175/1520-0469(1981)038<1601:ANCSOT>2.0.CO;2.
{{cite journal}}: CS1 maint: ref duplicates default (link) - Dewey, Kenneth; Mogil, H. Michael (June 23, 2017). "The Weather and Climate of Nebraska: The Heartland of Extremes". Weatherwise. 70 (4): 12–19. doi:10.1080/00431672.2017.1321919.
{{cite journal}}: CS1 maint: ref duplicates default (link) - Fuelberg, Henry E. (August 1979). Kinetic Energy Budgets in Areas of Convection (PDF) (Contractor Report). NASA. 3166. Retrieved May 12, 2024.
{{cite tech report}}: CS1 maint: ref duplicates default (link) - Hill, Kelly; Turner, Robert E. (February 1977). "NASA's Atmospheric Variability Experiments (AVE)". Bulletin of the American Meteorological Society: 170–172. JSTOR 26218060.
{{cite journal}}: CS1 maint: ref duplicates default (link) - Maddox, R. A.; Hoxit, L. R.; Chappell, C. F. (May 1979). Interactions Between Convective Storms and their Environment (PDF) (Contractor Report). National Oceanic and Atmospheric Administration. Retrieved May 9, 2024.
{{cite tech report}}: CS1 maint: ref duplicates default (link)- —; Hoxit, L. Ray; Chappell, Charles F. (March 1980). "A Study of Tornadic Thunderstorm Interactions with Thermal Boundaries". Monthly Weather Review. 108 (3). American Meteorological Society: 322–336. doi:10.1175/1520-0493(1980)108<0322:ASOTTI>2.0.CO;2.
{{cite journal}}: CS1 maint: ref duplicates default (link)
- —; Hoxit, L. Ray; Chappell, Charles F. (March 1980). "A Study of Tornadic Thunderstorm Interactions with Thermal Boundaries". Monthly Weather Review. 108 (3). American Meteorological Society: 322–336. doi:10.1175/1520-0493(1980)108<0322:ASOTTI>2.0.CO;2.
- Miller, Joseph A. (August 1979). An Example of Dry Line Convective Development: "The Omaha Tornado" (PDF) (Satellite Applications Information Note). Satellite Applications Information Notes, October 1975 – December 1978. Scott Air Force Base, Illinois: National Environmental Satellite Service. pp. 85–86. 76/12. Retrieved May 12, 2024.
{{cite tech report}}: CS1 maint: ref duplicates default (link) - Moore, James T.; Elkins, Harold A. (1985). "A Synoptic Analysis of the 6–7 May 1975 Omaha Tornado Outbreak". National Weather Digest. 10 (1). National Weather Association: 39–56. Retrieved May 9, 2024 – via CiteSeerX.
{{cite journal}}: CS1 maint: ref duplicates default (link) - National Weather Service Central Region Headquarters (1975). The Omaha Tornado: May 6, 1975 (PDF) (Disaster Survey Report). National Weather Service. Retrieved May 9, 2024.
- Ostby, Frederick P.; Pearson, Allen (February 1976). "The Tornado Season of 1975". Weatherwise. 29 (1): 16–23. doi:10.1080/00431672.1976.10543939.
- Peslen, Cynthia A. (February 1979). Impact of Short Interval SMS Digital Data on Wind Vector Determination for a Severe Local Storms Area (PDF) (Technical Memorandum). Greenbelt, Maryland: NASA. 79714. Retrieved May 9, 2024.
- — (September 1980). "Short-Interval SMS Wind Vector Determinations for a Severe Local Storms Area". Monthly Weather Review. 108 (9): 1407–1418. doi:10.1175/1520-0493(1980)108<1407:SISWVD>2.0.CO;2.
{{cite journal}}: CS1 maint: ref duplicates default (link)
- — (September 1980). "Short-Interval SMS Wind Vector Determinations for a Severe Local Storms Area". Monthly Weather Review. 108 (9): 1407–1418. doi:10.1175/1520-0493(1980)108<1407:SISWVD>2.0.CO;2.
External links[edit]
- Black Tuesday: May 6, 1975 Archived December 20, 2013, at the Wayback Machine