1999 Bridge Creek – Moore tornado
Encyclopedia
The 1999 Bridge Creek – Moore tornado was an extremely powerful F5
Fujita scale
The Fujita scale , or Fujita-Pearson scale, is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation...

 tornado
Tornado
A tornado is a violent, dangerous, rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as a twister or a cyclone, although the word cyclone is used in meteorology in a wider...

 which devastated towns just outside of Oklahoma City
Oklahoma city
Oklahoma City is the capital and largest city of the U.S. state of Oklahoma.Oklahoma City may also refer to:*Oklahoma City metropolitan area*Downtown Oklahoma City*Uptown Oklahoma City*Oklahoma City bombing*Oklahoma City National Memorial...

 on May 3, 1999. Throughout its one hour and 25 minute existence, the tornado covered 38 mi (61.2 km), destroying thousands of homes, killing 41 people and leaving $1 billion in losses behind. This ranks the tornado as the third costliest on record, not accounting for inflation. The tornado first touched down at 6:23 pm CDT in Grady County
Grady County, Oklahoma
Grady County is a county located in the U.S. state of Oklahoma. As of 2006, the population was 50,490. Its county seat is Chickasha.Grady County is part of the Oklahoma City Metropolitan Statistical Area.-History:...

, roughly 2 mi (3.2 km) south-southwest of Amber
Amber, Oklahoma
Amber is a town in Grady County, Oklahoma, United States. The population was 490 at the 2000 census.-Geography:Amber is located at .According to the United States Census Bureau, the town has a total area of , all of it land....

. It quickly intensified into a violent F4 system, and gradually reached F5 status after traveling 6.5 mi (10.5 km), at which time it struck the city of Bridge Creek
Bridge Creek, Oklahoma
Bridge Creek is a town in Grady County, Oklahoma, United States. As of the 2006 US Census estimate, the town is estimated to have a total population of 340.-Geography:Bridge Creek is located at ....

. Once it moved through the city, it fluctuated between F2 and F5 status as it crossed into Cleveland County
Cleveland County, Oklahoma
Cleveland County is a county in the central part of the U.S. state of Oklahoma. The population was 255,755 at the 2010 census. Its county seat is Norman. Cleveland County is part of the Oklahoma City Metropolitan Statistical Area.-History:...

. Not long after entering the county, it reached F5 intensity for a third time as it moved through the city of Moore
Moore, Oklahoma
Moore is a city in Cleveland County, Oklahoma and is part of the Oklahoma City Metropolitan Area. The population was 55,081 at the 2010 census, making it the seventh largest city in the state of Oklahoma....

. By 7:30 pm CDT, the tornado crossed into Oklahoma County
Oklahoma County, Oklahoma
Oklahoma County is a county located in the central partof the U.S. state of Oklahoma. The population was 718,633 at the 2010 census. The county seat and principal city is Oklahoma City...

 and battered southern Oklahoma City before dissipating around 7:48 pm CDT just outside Midwest City
Midwest City, Oklahoma
Midwest City is a city in Oklahoma County, Oklahoma, United States, and a part of the Oklahoma City metropolitan area. As of the 2010 census, the population was 54,371, making it the eighth largest city in the state....

.

Meteorological synopsis

The Bridge Creek – Moore tornado was part of a much larger tornado outbreak which spawned 71 tornadoes across five states on May 3 alone. On the morning of May 3, the Storm Prediction Center
Storm Prediction Center
The Storm Prediction Center , located in Norman, Oklahoma, is tasked with forecasting the risk of severe thunderstorms and tornadoes in the contiguous United States. The agency issues convective outlooks, mesoscale discussions, and watches as a part of this process...

 (SPC) stated that there was a slight risk for a severe weather event later that day as a dry line
Dry line
A dry line separates moist air from the Gulf of Mexico and dry desert air from the south-western states . The dry line is an important factor in severe weather frequency in the Great Plains of North America...

 that stretched from western Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

 into western Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 approached a warm, humid air-mass over the Central Plains. Although cirrus
Cirrus
Cirrus may refer to:In science:*Cirrus cloud, a type of cloud*Cirrus , a German research rocket*Cirrus, a fleshy, downward extension of the upper lip in salamanders or fish*Cirrus, a thoracic limb of an adult barnacle...

 clouds were present through much of the day, an eventual clearing allowed for the sun to heat up the moisture-laden region, creating significant atmospheric instability
Atmospheric instability
Atmospheric instability is a condition where the atmosphere is generally considered to be unstable and as a result the weather is subject to a high degree of variability through distance and time...

. By 7:00 am CDT, CAPE
Convective available potential energy
In meteorology, convective available potential energy , sometimes, simply, available potential energy , is the amount of energy a parcel of air would have if lifted a certain distance vertically through the atmosphere...

 values began exceeding 4,000 j/kg, a level which climatologically favors the development of severe thunderstorms. This prompted the SPC to upgrade the risk of severe weather to moderate for much of central Oklahoma
Oklahoma
Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...

.

By the early afternoon hours, forecasters at both the SPC and National Weather Service in Norman, Oklahoma
Norman, Oklahoma
Norman is a city in Cleveland County, Oklahoma, United States, and is located south of downtown Oklahoma City. It is part of the Oklahoma City metropolitan area. As of the 2010 census, Norman was to have 110,925 full-time residents, making it the third-largest city in Oklahoma and the...

 realized that a major event was likely to take place. Conditions became highly conductive for tornadic development by 1:00 pm CDT as wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...

 intensified over the region, creating a highly unstable atmosphere. At 3:49 pm CDT, a high-risk of severe weather was issued for much of central Oklahoma. Within minutes of this, supercell
Supercell
A supercell is a thunderstorm that is characterized by the presence of a mesocyclone: a deep, continuously-rotating updraft. For this reason, these storms are sometimes referred to as rotating thunderstorms...

s began developing over southwestern Oklahoma, prompting a severe thunderstorm warning
Severe thunderstorm warning
A severe thunderstorm warning is issued when trained storm spotters or a Doppler weather radar indicate a strong thunderstorm is producing dangerously large hail or high winds, capable of causing significant damage. In the United States, it does not account for lightning or flooding...

 by 4:15 pm CDT.
The thunderstorm that eventually spawned the F5 Bridge Creek – Moore tornado formed around 3:30 pm CDT over Tillman County
Tillman County, Oklahoma
Tillman County is a county located in the U.S. state of Oklahoma. As of 2000, the population was 9,287. The county seat is Frederick. .-Geography:According to the U.S...

. Tracking northeast, the storm strengthened and entered Comanche County
Comanche County, Oklahoma
Comanche County is a county located in the U.S. state of Oklahoma. Built on former reservation lands of the Comanche, Kiowa, and Apache in Indian Territory, Comanche County was open for settlement on August 16, 1901 by lottery. The region has three cities and seven towns as well as the Fort Sill...

 shortly after 4:00 pm CDT. There, hail
Hail
Hail is a form of solid precipitation. It consists of balls or irregular lumps of ice, each of which is referred to as a hail stone. Hail stones on Earth consist mostly of water ice and measure between and in diameter, with the larger stones coming from severe thunderstorms...

 up to 1.75 in (44.5 mm) in diameter fell; at 4:51 pm CDT, the first of 14 tornadoes associated with supercell "A" touched down along U.S. Route 62
U.S. Route 62
U.S. Route 62 runs from the US-Mexico border at El Paso, Texas to Niagara Falls, New York, near the United States-Canada border. It is the only east-west US Route that connects Mexico and Canada.Parts of U.S...

. Five more tornadoes touched down as the storm continued northeast; the sixth touchdown was an F3 which caused substantial damage in Grady County. At 6:23 pm CDT, the ninth tornado associated with supercell "A" touched down about 2 mi (3.2 km) south-southwest of Amber
Amber, Oklahoma
Amber is a town in Grady County, Oklahoma, United States. The population was 490 at the 2000 census.-Geography:Amber is located at .According to the United States Census Bureau, the town has a total area of , all of it land....

.

The tornado quickly intensified as it crossed Oklahoma State Highway 92
Oklahoma State Highway 92
State Highway 92, usually abbreviated as SH-92 or OK-92 , is a 2-section highway in the city of Chickasha and near the capital, Oklahoma City. The first section is long and stretches from US-277/62 in Chickasha to SH-37 in Tuttle...

, attaining F4 strength about 4 mi (6.4 km) east-northeast of Amber. This rating was sustained over the following 6.5 mi (10.5 km) before striking Bridge Creek
Bridge Creek, Oklahoma
Bridge Creek is a town in Grady County, Oklahoma, United States. As of the 2006 US Census estimate, the town is estimated to have a total population of 340.-Geography:Bridge Creek is located at ....

. There, it attained the highest-possible rating on the Fujita Scale, F5. Two homes were completely destroyed, leaving only a concrete slab where the homes once were. About 1 in (25.4 mm) of asphalt
Asphalt
Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...

 was torn off a road by the violent tornado. Continuing northeastward, the tornado briefly weakened to F4 status before becoming an F5 again as it neared the Grady-McClain border where a car was thrown roughly 0.25 mi (0.402335 km). At this time, it had attained a width of 1 mi (1.6 km). Around 6:57 pm CDT, the first-ever tornado emergency
Tornado emergency
A Tornado Emergency is enhanced wording of tornado warnings used by the National Weather Service in the United States during significant tornado occurrences in highly populated areas...

 was issued for the southern Oklahoma City Metro area.
Paralleling Interstate 44
Interstate 44
Interstate 44 is a major highway in the central United States. Its western terminus is in Wichita Falls, Texas at a concurrency with US 277, US 281 and US 287; its eastern terminus is at the Illinois state line on the Poplar Street Bridge over the Mississippi River in St...

, the tornado moved into McClain county where it crossed the highway twice at F4 intensity. At 7:10 pm CDT, a satellite tornado touched down over an open field north of Newcastle
Newcastle, Oklahoma
Newcastle is the largest city in McClain County, Oklahoma, United States, and a part of the Oklahoma City Metropolitan Area. The population was 7,685 at the 2010 census.-Geography:Newcastle is located at ....

; it was rated as an F0 due to lack of damage. After crossing the Canadian River
Canadian River
The Canadian River is the longest tributary of the Arkansas River. It is about long, starting in Colorado and traveling through New Mexico, the Texas Panhandle, and most of Oklahoma....

, the tornado entered Cleveland County and weakened to F2 intensity. By this time, it had entered the southern reaches of Oklahoma City. Several minutes after entering the county, it re-attained F4 status, destroying dozens of homes. Moving into the city of Moore
Moore, Oklahoma
Moore is a city in Cleveland County, Oklahoma and is part of the Oklahoma City Metropolitan Area. The population was 55,081 at the 2010 census, making it the seventh largest city in the state of Oklahoma....

, the tornado reached F5 intensity for a third time, leaving only concrete slabs where homes used to be. At 7:30 pm CDT, the tornado crossed into Oklahoma County, passing through the industrial district. After moving through Del City
Del City, Oklahoma
Del City is a city in Oklahoma County, Oklahoma, United States, and a part of the Oklahoma City metropolitan area. The population was 21,332 at the 2010 census....

 and Midwest City
Midwest City, Oklahoma
Midwest City is a city in Oklahoma County, Oklahoma, United States, and a part of the Oklahoma City metropolitan area. As of the 2010 census, the population was 54,371, making it the eighth largest city in the state....

, the tornado crossed Interstate 40
Interstate 40
Interstate 40 is the third-longest major east–west Interstate Highway in the United States, after I-90 and I-80. Its western end is at Interstate 15 in Barstow, California; its eastern end is at a concurrency of U.S. Route 117 and North Carolina Highway 132 in Wilmington, North Carolina...

 where hundreds of cars were tossed up to 0.2 mi (0.321868 km), some crashing into motels. Parts of the Rose State College
Rose State College
-History:Rose State College was originally named Oscar Rose Junior College in memory of Oscar V. Rose, a former Mid-Del School District school superintendent....

 campus were severely damaged as the tornado moved through; based on the damage, the tornado attained high-end F4 status, although F5 was considered as well. The tornado then began to rapidly dissipate as it moved through northeastern portion of the city. It finally lifted around 7:48 pm CDT just outside Midwest City. Throughout its one hour and 25 minute existence, the tornado tracked for 38 mi (61.2 km) across four counties.

Record
As the tornado moved into Oklahoma City, a mobile Doppler weather Radar
Doppler On Wheels
Doppler On Wheels is a fleet of radar trucks maintained by the Center for Severe Weather Research led by Joshua Wurman, with the funding mainly provided by the National Science Foundation...

 estimated sustained winds within the tornado between 281 and 321 mph (452.2 and 516.6 km/h), the highest winds ever recorded at the time. However, since the record for maximum winds are reported from only non-tornadic events, the 253 mph (407.2 km/h) wind gust from Cyclone Olivia
Cyclone Olivia
Severe Tropical Cyclone Olivia was a powerful Category 4 cyclone that produced the highest non-tornadic winds on record, 408 km/h .-Meteorological history:...

 in 1996 retained the title.

Impact

Impact by county
County Fatalities Injuries Damage
Grady
Grady County, Oklahoma
Grady County is a county located in the U.S. state of Oklahoma. As of 2006, the population was 50,490. Its county seat is Chickasha.Grady County is part of the Oklahoma City Metropolitan Statistical Area.-History:...

12 39 $90 million
McClain
McClain County, Oklahoma
McClain County is a county located in the U.S. state of Oklahoma. The population was 27,740 at the 2000 census. Its county seat is Purcell. McClain County is part of the Oklahoma City Metropolitan Statistical Area, and is in the top 3 fastest growing counties in Oklahoma with a growth rate of...

1 17 $10 million
Cleveland
Cleveland County, Oklahoma
Cleveland County is a county in the central part of the U.S. state of Oklahoma. The population was 255,755 at the 2010 census. Its county seat is Norman. Cleveland County is part of the Oklahoma City Metropolitan Statistical Area.-History:...

11 293 $450 million
Oklahoma
Oklahoma County, Oklahoma
Oklahoma County is a county located in the central partof the U.S. state of Oklahoma. The population was 718,633 at the 2010 census. The county seat and principal city is Oklahoma City...

12 234 $450 million
Unknown 5
Total 41 583 $1 billion

Throughout the tornado's path, 36 people were killed as a direct result of the storm and five more died in the hours following it. According to the Department of Health, an estimated 583 people were injured by the tornado, accounting for those who likely did not go to the hospital or were unaccounted for. In terms of structural lossess, a total of 8,132 homes, 1,041 apartments, 260 businesses, 11 public buildings and seven churches were damaged or destroyed. Total losses from the tornado reached $1 billion, making it the only tornado to cause such damage on record.

In Grady County, where the tornado first touched down, 12 people were killed and 39 others were injured. The tornado wrought catastrophic damage, especially in Bridge Creek, where the 1 mi (1.6 km) wide F5 system struck. Several homes were reduced to just concrete slabs and mobile homes were obliterated. Roughly 200 structures in the direct path of the tornado were completely destroyed. Twelve fatalities and most of the 39 injuries took place in the Willow Lake Addition, Southern Hills Addition, and Bridge Creek Estates of Bridge Creek, nine of which were in mobile homes. Losses in the county were estimated at $90 million.

Throughout most of the tornado's track through McClain county, it paralleled Interstate 44, avoiding most populated areas. However, one person was killed after she was blown out of an overpass near Newcastle
Newcastle, Oklahoma
Newcastle is the largest city in McClain County, Oklahoma, United States, and a part of the Oklahoma City Metropolitan Area. The population was 7,685 at the 2010 census.-Geography:Newcastle is located at ....

. In all, 17 people were injured, 40 structures were destroyed and 40 more were damaged. Losses in McClain were estimated at $10 million.
Some of the most severe damage took place in Cleveland County, especially in the city of Moore, where 11 people were killed and 293 others were injured. The tornado wrought an estimated $450 million in damage across the county. The first area impacted in Cleveland was Country Place Estates where 50 homes were damaged and one was completely destroyed, with only the foundation remaining. Several vehicles were picked up and tossed nearly 0.25 mi (0.402335 km). According to local police, an airplane wing, believed to have been from an airport in Grady County, was found near Country Place Estates. Next, the powerful tornado struck the densely populated Eastlake Estates at F5 intensity, killing three people and reducing entire rows of homes to rubble. In one instance, four adjacent homes were completely destroyed, with only concrete slabs remaining. In the Emerald Springs Apartments, three more people were killed and a two-story apartment was almost flattened.

Just outside the Eastlake Estates, a ceremony at Westmoore High School was behing held at the time of the tornado; however, adequate warning time allowed everyone to seek shelter and no injures took place at the ceremony. Ultimately, the school sustained heavy damage and dozens of cars in the parking lot were tossed around, many of which were destroyed. The tornado proceeded into the western city limits of Moore shortly thereafter. Near Janeway, four people were killed in an area where large sections of homes were completely destroyed. Afterwords, the tornado moved through a relatively sparsely populated area of Moore before entering Oklahoma County.

Aftermath

Following the outbreak of deadly and destructive tornadoes, President Bill Clinton
Bill Clinton
William Jefferson "Bill" Clinton is an American politician who served as the 42nd President of the United States from 1993 to 2001. Inaugurated at age 46, he was the third-youngest president. He took office at the end of the Cold War, and was the first president of the baby boomer generation...

 signed a major disaster declaration for 11 counties in Oklahoma on May 4. In a press statement by the Federal Emergency Management Agency
Federal Emergency Management Agency
The Federal Emergency Management Agency is an agency of the United States Department of Homeland Security, initially created by Presidential Reorganization Plan No. 1 of 1978 and implemented by two Executive Orders...

 (FEMA), director James Lee Witt
James Lee Witt
James Lee Witt was Director of the Federal Emergency Management Agency during the administration of President Bill Clinton....

 stated that "The President is deeply concerned about the tragic loss of life and destruction caused by these devastating storms." The American Red Cross
American Red Cross
The American Red Cross , also known as the American National Red Cross, is a volunteer-led, humanitarian organization that provides emergency assistance, disaster relief and education inside the United States. It is the designated U.S...

 opened ten shelters overnight, housing 1,600 people immediately following the disaster. By May 5, this number had lowered to 500. Throughout May 5, several post-disaster teams from FEMA were deployed to the region, including emergency response and preliminary damage assessment. The United States Department of Defense
United States Department of Defense
The United States Department of Defense is the U.S...

 deployed the 249th Engineering Battalion
249th Engineer Battalion (United States)
The 249th Engineer Battalion is a versatile power generation battalion assigned to the U.S. Army Corps of Engineers that provides commercial-level power to military units and federal relief organizations during full-spectrum operations. Additionally, the commander serves as the Commandant of the U.S...

 and placed the U.S. Army Corps of Engineers on standby for assistance. Medical and mortuary teams were also sent by the Department of Health and Human Services
United States Department of Health and Human Services
The United States Department of Health and Human Services is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. Its motto is "Improving the health, safety, and well-being of America"...

. By May 6, donation centers and phone banks were being established to create funds for victims of the tornadoes.

Continuing search and rescue efforts for 13 people who were listed as missing through May 7 were assisted by urban search and rescue dogs from across the country. Nearly 1,000 members of the Oklahoma National Guard
United States National Guard
The National Guard of the United States is a reserve military force composed of state National Guard militia members or units under federally recognized active or inactive armed force service for the United States. Militia members are citizen soldiers, meaning they work part time for the National...

 were deployed throughout the affected region. The American Red Cross had set up ten mobile feeding stations by this time and stated that 30 more were en route. On May 8, a disaster recovery center was opened in Moore for individuals recovering from the tornadoes. According to the Army Corps of Engineers, roughly 500,000 cubic yards (382,277 cubic meters) of debris was left behind and would likely take weeks to clear. Within the first few days of the disaster declaration, relief funds began being sent to families who requested aid. By May 9, roughly $180,000 had been approved by FEMA for disaster housing assistance.
Debris removal finally began on May 12 as seven cleanup teams were sent to the region, more were expected to join over the following days. That day, FEMA also declared that seven counties, Canadian, Craig, Grady, Lincoln, Logan, Noble and Oklahoma, were eligible for federal financial assistance. By May 13, roughly $1.6 million in disaster funds had been approved for housing and businesses loans. This quickly rose to more than $5.9 million over the following five days. By May 21, more than 3,000 volunteers from across the country traveled to Oklahoma to help residents recover; 1,000 of these volunteers were sent to Bridge Creek to clean up debris, cut trees, sort donations and cook meals. With a $452,199 grant from FEMA, a 60-day outreach program for victims suffering tornado-related stress was set up to help them deal cope with trauma.

Applications for federal aid continued through June, with state approvals reaching $54 million on June 3. By this date, the Army Corps of Engineers reported that 964,170 cubic yards (737,160 cubic meters), roughly 58%, of the 1.65 million cubic yards (1.26 million cubic meters) of debris had been removed. Assistance for farmers and ranchers who suffered severe losses from the tornadoes was also available by June 3. After more than a month of being open, emergency shelters were set to be closed on June 18. On June 21, an educational road show made by FEMA visited the hardest hit areas in Oklahoma to urge residents to build storm cellar
Storm cellar
A storm shelter or storm cellar is a type of underground bunker designed to protect the occupants from violent severe weather, particularly tornadoes...

s. According to FEMA, more than 9,500 residents applied for federal aid during the allocated period in the wake of the tornadoes. Most of the applicants lived in Oklahoma and Cleveland counties, 3,800 and 3,757 persons respectively. In all, disaster recovery aid for the tornadoes amounted to roughly $67.8 million by the end of July 2.
From a meteorological and safety standpoint, the tornado also brought the use of highway overpasses as shelters into question. Prior to the events on May 3, 1999, videos of people taking shelter in overpasses during tornadoes in the past gave the public misunderstanding that overpasses provided shelter from tornadoes. For nearly 20 years, meteorologists had questioned the safety of these structures; however, they lacked incidents involving loss of life. During the May 3 outbreak, three overpasses were directly struck by tornadoes, with a fatality taking place at each one. Two of these were from the F5 Bridge Creek – Moore tornado while the third was from a small, F2 which struck a rural area north of Oklahoma City. According to a study by the National Oceanic and Atmospheric Administration, seeking shelter in an overpass "is to become a stationary target for flying debris."

Over the following four years, a $12 million project to construct storm shelters for residents across Oklahoma City was enacted. The goal was to create a safer community in a tornado-prone region. By May 2003, a total of 6,016 safe rooms were constructed. On May 9, 2003, the new initiative was put to the test as a tornado outbreak in the region spawned an F4 tornado which took a path similar to that of the Bridge Creek – Moore tornado. Due to the higher standards for public safety, no one was killed by the tornado in 2003, a substantial improvement in just four years.

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