The 1999 Bridge Creek–Moore tornado was a large, long-lived, and exceptionally violent F5 tornado that produced the highest tornado wind speed ever recorded by doppler weather radar—, measured by a Doppler on Wheels (DoW). One of the strongest tornadoes ever recorded to affect a metropolitan area, the tornado devastated southern portions of Oklahoma City, Oklahoma, as well as surrounding municipalities to the south and southwest of the city during the early evening of Monday, May 3, 1999. The tornado covered during its 85-minute existence, destroying thousands of homes, killing 36 people (plus another five indirectly), and causing US$1 billion (1999 USD) in damage, ranking it as the fifth-costliest on record not accounting for inflation. Its severity prompted the first-ever use of the tornado emergency statement by the National Weather Service.
The tornado first touched down at 6:23 p.m. Central Daylight Time (CDT) in Grady County, roughly south-southwest of the town of Amber. It quickly intensified into a violent F4, and gradually reached F5 status after traveling , at which time it struck the town of Bridge Creek, where parts of the community were rendered unrecognizable. It fluctuated in strength, ranging from F2 to F5 status before it crossed into Cleveland County where it reached F5 intensity for a third time shortly before entering the city of Moore. By 7:30 p.m., the tornado crossed into Oklahoma County and battered southeastern Oklahoma City, Del City, and Midwest City before dissipating around 7:48 p.m. just outside Midwest City. The greatest impacts from the tornado occurred near peak intensity in the densely populated southern suburbs and exurbs of the Oklahoma City metropolitan area. A total of 8,132 homes, 1,041 apartments, 260 businesses, eleven public buildings, and seven churches were damaged or destroyed.
Large-scale search and rescue operations immediately took place in the affected areas. A major disaster declaration was signed by President Bill Clinton the following day (May 4) allowing the state to receive federal aid. In the following months, disaster aid amounted to $67.8 million. Reconstruction projects in subsequent years led to a safer, tornado-ready community. On May 20, 2013, nearby areas adjacent to the 1999 storm's track were again devastated by another large and violent EF5 tornado, resulting in 24 fatalities and extreme damage in the South Oklahoma City/Moore area.
Meteorological synopsis
The Bridge Creek–Moore tornado was part of a much larger outbreak which produced 71 tornadoes across five states throughout the Central Plains on May 3 alone, along with an additional 25 that touched down a day later in some of the areas affected by the previous day's activity (some of which were spawned by supercells that developed on the evening of May 3), stretching eastward to the Mississippi River Valley. The most prolific tornadic activity associated with the May 3 outbreak – and the multi-day outbreak as a whole – occurred in Oklahoma; 14 of the 66 tornadoes that occurred within the state that afternoon and evening produced damage consistent with the Fujita scale's "strong" (F2–F3) and "violent" (F4–F5) categories, which, in addition to the areas struck by the Bridge Creek–Moore tornado family, affected towns such as Mulhall, Cimarron City, Dover, Choctaw and Stroud. Setup The outbreak was caused by a vigorous upper-level trough that moved into the Central and Southern Plains states on the morning of May 3. That morning, low stratus clouds overspread much of Oklahoma, with clear skies along and west of a dry line located from Gage to Childress, Texas. Air temperatures at 7:00 a.m. Central Daylight Time ranged in the mid to upper 60s °F (upper 10s to near 20 °C) across the region, while dew point values ranged in the low to mid 60s °F (mid to upper 10s °C).Meteorological Summary of the Great Plains Tornado Outbreak of May 3-4, 1999 The Storm Prediction Center (SPC) in Norman, Oklahoma, a division of the National Weather Service, initially issued a slight risk of severe thunderstorms early that morning stretching from the Kansas-Nebraska border to parts of southern Texas, with an intended threat of large hail, damaging winds and tornadoes. By late morning, the low cloud cover began to dissipate in advance of the dry line, but during the afternoon high cirrus clouds overspread the region, resulting in filtered sunshine in some areas that caused atmospheric destabilization. The sunshine and heating, combined with abundant low-level moisture, combined to produce a very unstable air mass. Upper air balloon soundings observed strong directional wind shear, cooling temperatures at high atmospheric levels, and the increased potential of CAPE values potentially exceeding 4000 J/kg, levels that are considered favorable for supercells and tornadoes. Forecast and initiation
As observations and forecasts began to indicate an increasing likelihood of widespread severe weather conditions even more favorable for strong tornadoes, the SPC issued a moderate risk of severe weather at 11:15 a.m. CDT for portions of Kansas, Oklahoma and Texas along and near the Interstate 40 corridor.
At 3:49 p.m. CDT, the SPC − having gathered enough data to surmise that there was a credible threat of a significant severe weather outbreak occurring within the next few hours − amended its Day 1 Convective Outlook to place the western nine-tenths of the main body of Oklahoma, central and south-central Kansas and the northern two-thirds of Texas under a high severe weather risk, denoting a higher than normal probability of strong (F2+) tornadoes within the risk area. About 40 minutes after the revised outlook's issuance, at 4:30 p.m. CDT, the SPC issued a tornado watch for western and central Oklahoma, effective from 4:45 p.m. until 10:00 p.m. CDT that evening, for the threat of tornadoes, hail up to in diameter, wind gusts to and intense lightning. As that happened, the first thunderstorm cell of the unfolding event had already formed over southwestern Oklahoma.
Storm development and tornado summary Supercell thunderstorm develops The thunderstorm that eventually produced the F5 tornado began developing around 3:20 p.m. CDT that afternoon over northeastern Tillman County (southwest of Faxon). Despite the lack of overall lift prevalent in the region, the storm formed out of a contrail-like horizontal area of convective clouds that developed during peak surface heating over southwestern Oklahoma, located well ahead of the dry line that was still positioned farther to the west, which provided enhanced lift and speed shear necessary to develop the supercell. Tracking northeast, the storm strengthened and entered Comanche County shortly after 4:00 p.m. CDT. By 4:15 p.m. CDT, the NWS Norman office issued a severe thunderstorm warning for Comanche County, as the initial storm continued to rapidly intensify over the southern half of the county; there, hail up to in diameter fell.As the supercell's mesocyclonic rotation began to rapidly strengthen at the cloud base, a tornado warning was issued for the counties of Comanche, Caddo, and Grady at 4:50 p.m. CDT; one minute later, a small tornado roughly in diameter − the first of fourteen associated with supercell "A" (NWS Norman designated lettered names for the three tornado-producing supercells in the outbreak in storm surveys) − developed east-northeast of Medicine Park along U.S. Route 62. Five more tornadoes developed as the storm continued northeast; a sixth one, which would be given an F3 rating, formed a short time later and caused substantial damage in central Grady County, including some to the Chickasha Municipal Airport, where roofs were torn off of two hangars. Bridge Creek–Moore tornado forms
At 6:23 p.m. CDT, a ninth tornado associated with supercell "A" began about south-southwest of Amber. The tornado rapidly intensified and grew in size as it crossed Oklahoma State Highway 92, attaining F4 strength about east-northeast of Amber. It quickly grew into a wedge tornado, varying between in width at various points throughout the track. Damage consistent with this rating was sustained over the following of the path before striking Bridge Creek. There, it attained the highest-possible rating on the Fujita Scale, F5. As it passed just to the north and east of Interstate 44 near the Oklahoma State Highway 4 interchange, a mobile Doppler On Wheels (DOW) radar operated by the University of Oklahoma’s Mobile Radar Research Lab – now the Flexible Array of Radars and Mesonets (FARM) – that was traveling northeast and observing the tornado from the south, initially recorded winds of within the tornado at 6:54 p.m. CDT – subsequent reanalysis in 2021 revised this value to , the highest wind speed ever recorded within a tornado.
Damage in Bridge Creek was extreme, as many homes were swept away completely, leaving only concrete slabs where the structures once stood. Damage surveyors noted that the remaining structural debris from some of the homes in this area was finely granulated into small fragments, and that trees and shrubs were completely debarked. A few of these homes were bolted to their foundations. Approximately 200 houses and mobile homes were destroyed, and hundreds of other structures were damaged. The Ridgecrest Baptist Church in Bridge Creek was also destroyed in the process. Extensive ground scouring occurred, and vehicles were thrown hundreds of yards from where they originated, including a mangled pickup truck that was found wrapped around a telephone pole. About of asphalt was scoured off one road.
Twelve people died in Bridge Creek, nine of whom were in mobile homes; all fatalities and the majority of injuries were concentrated in the Willow Lake and Southern Hills Additions and Bridge Creek Estates, consisting mostly of mobile homes. Over 39 people were injured in the area as well. Continuing northeastward, the tornado briefly weakened to F4 status before re-strengthening to F5 intensity as it neared the Grady-McClain County line, where a car was thrown roughly in the air, and a well-built home with anchor bolts was reduced to a bare slab. At this time, it had attained a width of , having grown to its largest width after crossing the South Canadian River into the southern Oklahoma City limits. The tornado then became quickly rain-wrapped; Jim Gardner, then-helicopter pilot for KFOR-TV, reported during the station's live coverage of the storm that the tornado was at least one mile wide, and was embedded (or "rain-wrapped") in the precipitation core associated with the main circulation, making it difficult to see.
As it was becoming clear that a particularly violent tornado was moving into some of the most densely populated areas of central Oklahoma, around 6:57 p.m. CDT, NWS Norman issued the first-ever tornado emergency for southern portions of the Oklahoma City metropolitan area. David Andra, a meteorologist at the NWS Norman office, said that, in drafting the enhanced warning, he wanted to "paint the picture [to residents] that a rare and deadly tornado was imminent in the metro area."
SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE NORMAN OK 657 PM CDT MON MAY 3 1999
...TORNADO EMERGENCY IN SOUTH OKLAHOMA CITY METRO AREA...
AT 657 PM CDT...A LARGE TORNADO WAS MOVING ALONG INTERSTATE 44 WEST OF NEWCASTLE. ON ITS PRESENT PATH...THIS LARGE...DAMAGING TORNADO WILL ENTER SOUTHWEST SECTIONS OF THE OKLAHOMA CITY METRO AREA BETWEEN 715 PM AND 730 PM. PERSONS IN MOORE AND SOUTH OKLAHOMA CITY SHOULD TAKE IMMEDIATE TORNADO PRECAUTIONS.
THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. IF YOU ARE IN THE PATH OF THIS LARGE AND DESTRUCTIVE TORNADO...TAKE COVER IMMEDIATELY.
DOPPLER RADAR HAS INDICATED THIS STORM MAY CONTAIN DESTRUCTIVE HAIL TO THE SIZE OF BASEBALLS...OR LARGER.