Timespan January–December 1999 Fatalities (U.S.) 94 | Damage (U.S.) $2 billion Fatalities (worldwide) >94 | |
 | ||
Maximum rated tornado F5 tornado
Bridge Creek–Moore, Oklahoma
on May 3 Tornadoes in U.S. 1,339
(Sixth-highest since 1952) | ||
This page documents the tornadoes and tornado outbreaks of 1999, primarily (but not entirely) in the United States. Most tornadoes form in the U.S., although some events may take place internationally, particularly in parts of neighboring southern Canada during the Northern Hemisphere's summer season. Some tornadoes also take place in Europe, e. g. in the United Kingdom or in Germany. One particular event, the Bridge Creek, Oklahoma F5 tornado, was known to produce the highest wind speed ever recorded on Earth, which was 301 ± 20 mph (484 ± 32 km/h).
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United States
During 1999, a total of 1,339 tornadoes touched down across the United States, ranking it as the fourth-most active year at the time; it has since been surpassed by two other years. The year began with the most active January on record, featuring 216 tornadoes. Culminating with the largest outbreak in the month, with over 100 tornadoes touching down on January 21 and 22 (surpassing the previous daily record of 39 on January 10, 1975), many records were broken. Due in large part to this outbreak, Arkansas saw more tornadoes in 1999 than any other year, with 107 recorded, and its most active January. The state also broke the record for most tornadoes in January of any state.
Europe
The European Severe Storms Laboratory maintains a database of all severe weather events across the continent. The vast majority of tornadoes go unrated due to a lack of surveys; however, some nations, such as France, provide detailed reports on these events. Of the 87 reported tornadoes during 1999, 45 were rated.
January
Exceptional tornado activity took place across the United States in January, with 216 tornadoes touching down, more than ten times the average of 20. This set the record for most tornadoes recorded in the month, and more than quadrupled the previous record of 52 set in 1975. January 21, 1999 marked the single-most active day in the month on record, with 87 tornadoes forming. The extreme activity during the month was attributed to an unusually spring-like setup, with a warm, moist air mass from the Gulf of Mexico flowing northward into an area with strong upper-level westerlies. The synoptic set up of these factors was typical of March or April rather than mid-winter.
January 1–3
On January 1, a strong upper-level low moved over Southeast Texas, while an accompanying surface low formed over North Texas. A cold front extended southward from this surface low into the Gulf of Mexico. Ahead of this front, a strong low level jet formed, bringing a surge of warm, moist air from the Gulf northward. The combination of these factors resulted in an unstable environment favoring the development of rotating supercell thunderstorms.
January 18 (South Africa)
On January 18, a violent F4 tornado struck Mount Ayliff and Tabankulu in Eastern Cape, South Africa. The majority of the towns were destroyed, with 95 percent of residents left homeless. Numerous vehicles were lofted significant distances by the storm, with one traveling 500 m (1,600 ft). The deadliest tornado on record in South Africa, 25 people were killed and approximately 500 others were injured.
February
There were 22 tornadoes confirmed in the US in the month of February.
One person was killed and another was injured when a tornado struck Serik, Turkey, on February 13.
March
There were 56 tornadoes confirmed in the US in the month of March.
April
There were 177 tornadoes confirmed in the US in the month of April.
April 2–3
One F4 tornado touched down in Louisiana. The final outbreak tally was seventeen tornadoes.
May
There were 310 confirmed tornadoes in the US in the month of May
May 9–12
A slow-moving cold front produced several days of severe weather across the central states. From May 9 to 10, many weak tornadoes touched down from South Dakota to Texas. The most notable tornadoes occurred on May 11 as multiple supercells developed along the cold front in Oklahoma and Texas. Shortly after 6:00 p.m. CDT (2300 UTC), a 0.75 mi (1.21 km) wide multiple-vortex tornado struck Mason County, Texas. Remaining on the ground for 7 mi (11 km), the F4 tornado leveled two homes and scattered debris over great distances. In one of the homes, six people sought refuge in a car within their garage; debris fell on the car, killing one and injuring the other five. A pick-up truck was torn apart and pieces of it were found 0.75 mi (1.21 km) away. Sixteen other homes were damaged by the tornado in addition to numerous barns and outbuildings. A large section of asphalt was ripped out by the tornado as well. A few hours later, an F3 tornado touched down in Gillespie County. That tornado damaged or destroyed 70 structures and tossed vehicles up to 100 yards (91 m). Damage from the storm reached $1 million. On May 12, activity was again limited to a few weak tornadoes.
May 15 (China)
On May 15, a tornado struck rural areas of Suixi County, Guangdong, China, killing 13 people and causing extensive damage. The majority of damage occurred in Qinge Village. Nine people were killed in the town while four others later died of their injuries. A total of 178 homes were destroyed while 489 more were damaged. An additional 51 people were injured, 35 seriously, and damage was estimated at $414 million.
June
There were 289 tornadoes confirmed in the US in the month of June.
June 4
A supercell produced a tornado around San Quirino, Italy, causing damage to houses, sheds, and trees along a path width of about 300 m and length of less than 10 km.
July
There were 102 tornadoes confirmed in the US in the month of July.
August
There were 79 tornadoes confirmed in the US in the month of August.
August 11–13
On August 11, a cold upper-level trough moved into Utah. By the afternoon, a frontal boundary or convergence zone developed over the state. With sufficient wind shear and instability, thunderstorms that developed along this boundary became severe. One particular storm over the Salt Lake Valley grew to 41,000 ft (12 km) and produced a strong tornado that struck Salt Lake City. Touching down at 12:41 p.m. MDT (1841 UTC), the tornado quickly intensified as it moved through the metropolitan area for 4.3 mi (6.9 km). Attaining F2 intensity, the storm damaged or destroyed 300 structures, including the Delta Center and the city's capitol building. Overall, one person was killed, 80 were injured, and losses amounted to $170 million, making it the most destructive tornado in the state's history. Attaining a maximum width of 150 yd (140 m), this tornado ranked as the largest on record in Utah. Four weaker tornadoes touched down across South Dakota and Wyoming on August 12. The following two days featured seven additional tornadoes, none of which exceeded F1 intensity. Alongside the tornadoes, straight-line winds caused extensive damage in many states from August 11–13. In Pitkin County, Colorado, one storm produced winds up to 115 mph (185 km/h), downing hundreds of trees over a 3-square-mile (7.8 km2) area. These winds resulted in one fatality and $56.9 million in losses, the majority coming from crop damage.
August 29 (South Africa)
On August 29, a powerful tornado struck Cape Flats, South Africa. Causing damage along a path at least 1 mi (1.6 km) long and 1,000 yd (910 m) wide, it moved through the impoverished neighborhood of Manenberg. At least four people were killed, while a fifth died from a heart attack, and 220 were injured. Approximately 5,000 people were left homeless.
September
There were 56 tornadoes confirmed in the US in the month of September.
On September 24, a tornado struck the city of Toyohashi, Aichi, Japan, destroying three homes and damaging many others. A total of 262 people sustained minor injuries, mainly schoolchildren, from shattered glass.
September 15
As Hurricane Floyd neared landfall in North Carolina, its outer bands spawned 17 tornadoes across the state. The majority were weak, though two produced F2 damage.
October
There were 17 tornadoes confirmed in the United States in the month of October. On October 13, a squall line originating in Illinois produced and F3 tornado in Pickaway County, Ohio, that destroyed several homes and injured six people. The storm was responsible for $4 million in damage.
October 15
As Hurricane Irene neared landfall in Florida, it spawned 4 tornadoes across the state.
October 21 (South Africa)
On October 21, a severe thunderstorm developed about 50 km (31 mi) south of Johannesburg, South Africa. Lasting about an hour and a half, the storm produced two tornadoes, one F3 and one F1, along its path. The first tornado was on the ground for roughly 100 km (62 mi) and had a peak width of 250 m (270 yd). The tornado mostly remained over open areas, though significant damage occurred in Heidelberg, Gauteng. There, 40 people sustained injuries and 400 structures were damaged. At an unknown point along the path, the tornado sucked up nearly all the water in a large shallow dam and deposited it on nearby hills.
November–December
There were 7 and 15 tornadoes confirmed in the United States in the months from November to December, respectively.
November 26
On November 26, a cold front moved into an unseasonably warm air mass over Pennsylvania, resulting in the formation of a tornado in Chester County. Rated high-end F1, the tornado destroyed 6 structures and damaged 26 more, leaving $3 million in losses; 12 people were injured.
December 2–4
Almost all of the tornadoes in December touched down between December 2 and 4. One of these tornadoes in Oklahoma was rated F2 and tracked for 12 mi (19 km), while another in Texas, rated F1, killed two people when it destroyed a mobile home.
December 9
An isolated F3 tornado occurred on December 9 in Yazoo County, Mississippi, destroying two mobile homes and downing thousands of trees.