From April 27–29, 1912, a major

tornado outbreak __NOTOC__ A tornado outbreak is the occurrence of multiple tornadoes spawned by the same synoptic scale weather system. The number of tornadoes required to qualify as an outbreak typically are at least six to ten, with at least two rotational l ...

generated at least six violent tornadoes in

Oklahoma Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...

, with near-constant activity until early the next day. At least 15 cities were affected, 40 people died, and 120 others were injured. Tornado researcher

Thomas P. Grazulis Thomas P. Grazulis (born August 17, 1942) is an American meteorologist who has written extensively about tornadoes and is head of ''The Tornado Project''. Biography Early career Thomas Grazulis grew up in Worcester, Massachusetts and first c ...

considered this outbreak to be among the worst on record in the state of Oklahoma, as measured by fatalities and violent tornadoes. At least five strong tornadoes affected

Washita County, Oklahoma Washita County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 11,629. Its county seat is New Cordell. The county seat was formerly located in Cloud Chief. The county was created in 1891. History ...

, during this outbreak.

Background

Limited weather data were collected and recorded at that time in Oklahoma. Antedating upper atmospheric measurements, most data collection was of human observations, along with temperature, pressure, wind speed and direction, and rainfall. A

cold front A cold front is the leading edge of a cooler mass of air at ground level that replaces a warmer mass of air and lies within a pronounced surface trough of low pressure. It often forms behind an extratropical cyclone (to the west in the Norther ...

moved south through Oklahoma into Texas on April 26, before stalling as a stationary front draped across

Central Texas Central Texas is a region in the U.S. state of Texas surrounding Austin and roughly bordered by San Saba to Bryan and San Marcos to Hillsboro. Central Texas overlaps with and includes part of the Texas Hill Country and corresponds to a ph ...

, oriented from northeast to southwest. Early on April 27, it pushed back northward against a

warm front A warm front is a density discontinuity located at the leading edge of a homogeneous warm air mass, and is typically located on the equator-facing edge of an isotherm gradient. Warm fronts lie within broader troughs of low pressure than cold fro ...

to the east, due to a vigorous upper-atmospheric

trough Trough may refer to: In science * Trough (geology), a long depression less steep than a trench * Trough (meteorology), an elongated region of low atmospheric pressure * Trough (physics), the lowest point on a wave * Trough level (medicine), the l ...

approaching from the west. The warm front was noted to have moved from the southeast on April 27 to the northeast on April 28; this movement of warm air against the cold front, in proximity to a

low-pressure area In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

over western Oklahoma, provided sufficient atmospheric lift, thereby fuelling the storms that provided the tornado activity.

Confirmed tornadoes

April 27 event

April 28 event

April 29 event

Notes

References

Sources

* * * {{DEFAULTSORT:1912-04-27 Oklahoma tornado outbreak

Tornadoes in Oklahoma F4 tornadoes by date Oklahoma,1912-04-27 History of Oklahoma 1912 in Oklahoma 1912 natural disasters in the United States

Tornado outbreak __NOTOC__ A tornado outbreak is the occurrence of multiple tornadoes spawned by the same synoptic scale weather system. The number of tornadoes required to qualify as an outbreak typically are at least six to ten, with at least two rotational l ...