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Tropical Storm Allison (1989)
Encyclopedia
Tropical Storm Allison was a tropical cyclone that produced severe flooding in the southern United States
. The second tropical cyclone and the first named storm of the 1989 Atlantic hurricane season
, Allison formed on June 24 in the northwestern Gulf of Mexico
. Development of Allison was a result of the interaction of a tropical wave and the remnants of Pacific hurricane Hurricane Cosme
. It moved south and became a tropical storm on June 26. By June 27, Allison made landfall near Freeport, Texas
. Allison quickly weakened to a tropical depression later that day, and transitioned into an extratropical cyclone
on the following day.
The storm caused heavy rainfall, amounting to 30 in (762 mm) in some places. In total, 11 fatalities resulted from the storm, as well as $560 million (1989 USD, $ USD) in damage.
moved northward through Mexico
in response to a strong mid to upper-level ridge. Its remnants entered the Gulf of Mexico
on June 22, when a westward moving tropical wave reached the area. Finally, a strong anticyclone over the Gulf allowed for the disturbed area to organize into Tropical Depression Two in the western Gulf of Mexico on June 24.
The depression continued to organize as it drifted to the north, and became Tropical Storm Allison on June 26 off the Texas coast. A ridge to Allison's north weakened in response to an approaching frontal trough, and the tropical storm accelerated to the north. Allison reached a peak of 50 mi/h winds just before hitting near Freeport, Texas on June 27. It turned to the northeast with the front, weakened to a tropical depression on June 27, and became extratropical on June 28.
The frontal trough outran the system, and the building ridge to Allison's north forced the extratropical depression turned to the south and southwest. After executing a cyclonic loop over Texas, the ridge to the north began to erode, allowing Allison to track northeast and out of the state. Its circulation dissipated on July 1, but the remnants retained some organization, and continued to the northeast. On July 3 and July 4, the shortwave that influenced the remnants of Allison accelerated ahead of the storm, causing Allison to become stationary over the borders of Kentucky
, Illinois
, and Indiana
. A second shortwave trough brought the remnants of Allison southward into Alabama
. It turned to the northwest, and the remnants of Allison became unidentifiable over Arkansas on July 7.
to Morgan City, Louisiana
. By June 26, this alert was upgraded to a tropical storm warning. All advisories were discontinued the next day.
While Allison's winds weren't overly strong, it caused tremendous flooding in Texas and Louisiana, with 20 to 25 in (508 to 635 mm) in of rain occurring in some locations. The local hardest hit by the flooding was Winnfield, Louisiana
, which experienced almost 30 in (762 mm) of rain from June 26 to July 1.
Rainfall from the storm extended eastward into the Mid-Atlantic States
, producing flooding. In Delaware
, the rainfall led to record breaking discharge rates at three gauging stations, while one-third of the state's gauging stations reported significant discharges.
13.9 in (353.1 mm) of rain fell at a site in Arkansas
, the highest rainfall total from a tropical cyclone in the state.
Eleven people were reported killed from the storm. Three deaths occurred in Texas, five in Mississippi and three in Louisiana. Two teenage boys were killed when their raft got sucked into a drainage pipe from the runoff of Allison in Beaumont, Texas
. An eighteen-year-old was killed in Harris County, Texas from drowning during a swim. The eight final deaths in Louisiana and Mississippi were by drowning. The extreme flooding in turn led to heavy damage, amounting to around $560 million (1989 USD, $ USD).
Southern United States
The Southern United States—commonly referred to as the American South, Dixie, or simply the South—constitutes a large distinctive area in the southeastern and south-central United States...
. The second tropical cyclone and the first named storm of the 1989 Atlantic hurricane season
1989 Atlantic hurricane season
The 1989 Atlantic hurricane season was an active season that produced fifteen tropical cyclones, eleven named storms, seven hurricanes, and two major hurricanes. The season was officially designated from June 1, 1989, to November 30, 1989, dates which conventionally...
, Allison formed on June 24 in the northwestern Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
. Development of Allison was a result of the interaction of a tropical wave and the remnants of Pacific hurricane Hurricane Cosme
Hurricane Cosme (1989)
Hurricane Cosme was the third tropical cyclone and second hurricane of the 1989 Pacific hurricane season. Forming on June 19 from a tropical wave, the storm initially moved westward before being upgraded into Tropical Storm Cosme. It ultimately intensifying into a Category 1 hurricane. Cosme turned...
. It moved south and became a tropical storm on June 26. By June 27, Allison made landfall near Freeport, Texas
Freeport, Texas
Freeport is a city in Brazoria County, Texas within the Houston–Sugar Land–Baytown metropolitan area and is situated in Southeast Texas. As of the 2000 U.S...
. Allison quickly weakened to a tropical depression later that day, and transitioned into an extratropical cyclone
Extratropical cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of cyclones defined as synoptic scale low pressure weather systems that occur in the middle latitudes of the Earth having neither tropical nor polar characteristics, and are connected with fronts and...
on the following day.
The storm caused heavy rainfall, amounting to 30 in (762 mm) in some places. In total, 11 fatalities resulted from the storm, as well as $560 million (1989 USD, $ USD) in damage.
Meteorological history
Three meteorological phenomena combined to produce Tropical Storm Allison. First, Hurricane CosmeHurricane Cosme (1989)
Hurricane Cosme was the third tropical cyclone and second hurricane of the 1989 Pacific hurricane season. Forming on June 19 from a tropical wave, the storm initially moved westward before being upgraded into Tropical Storm Cosme. It ultimately intensifying into a Category 1 hurricane. Cosme turned...
moved northward through Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
in response to a strong mid to upper-level ridge. Its remnants entered the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
on June 22, when a westward moving tropical wave reached the area. Finally, a strong anticyclone over the Gulf allowed for the disturbed area to organize into Tropical Depression Two in the western Gulf of Mexico on June 24.
The depression continued to organize as it drifted to the north, and became Tropical Storm Allison on June 26 off the Texas coast. A ridge to Allison's north weakened in response to an approaching frontal trough, and the tropical storm accelerated to the north. Allison reached a peak of 50 mi/h winds just before hitting near Freeport, Texas on June 27. It turned to the northeast with the front, weakened to a tropical depression on June 27, and became extratropical on June 28.
The frontal trough outran the system, and the building ridge to Allison's north forced the extratropical depression turned to the south and southwest. After executing a cyclonic loop over Texas, the ridge to the north began to erode, allowing Allison to track northeast and out of the state. Its circulation dissipated on July 1, but the remnants retained some organization, and continued to the northeast. On July 3 and July 4, the shortwave that influenced the remnants of Allison accelerated ahead of the storm, causing Allison to become stationary over the borders of Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
, Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
, and Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
. A second shortwave trough brought the remnants of Allison southward into Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
. It turned to the northwest, and the remnants of Allison became unidentifiable over Arkansas on July 7.
Preparations
In preparation for Tropical Storm Allison, a tropical storm watch was issued on June 24 for Baffin Bay, TexasBaffin Bay, Texas
Baffin Bay is a bay in South Texas, an inlet of the larger Laguna Madre. Located near the Gulf of Mexico, Baffin Bay forms part of the boundary between Kenedy County and Kleberg County.-Etymology:The history of the bay name is unclear...
to Morgan City, Louisiana
Morgan City, Louisiana
Morgan City is a city in St. Martin and St. Mary parishes in the U.S. state of Louisiana. The population was 12,404 at the 2010 census....
. By June 26, this alert was upgraded to a tropical storm warning. All advisories were discontinued the next day.
Impact
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
, which experienced almost 30 in (762 mm) of rain from June 26 to July 1.
Rainfall from the storm extended eastward into the Mid-Atlantic States
Mid-Atlantic States
The Mid-Atlantic states, also called middle Atlantic states or simply the mid Atlantic, form a region of the United States generally located between New England and the South...
, producing flooding. In Delaware
Delaware
Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania...
, the rainfall led to record breaking discharge rates at three gauging stations, while one-third of the state's gauging stations reported significant discharges.
13.9 in (353.1 mm) of rain fell at a site in Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
, the highest rainfall total from a tropical cyclone in the state.
Eleven people were reported killed from the storm. Three deaths occurred in Texas, five in Mississippi and three in Louisiana. Two teenage boys were killed when their raft got sucked into a drainage pipe from the runoff of Allison in Beaumont, Texas
Beaumont, Texas
Beaumont is a city in and county seat of Jefferson County, Texas, United States, within the Beaumont–Port Arthur Metropolitan Statistical Area. The city's population was 118,296 at the 2010 census. With Port Arthur and Orange, it forms the Golden Triangle, a major industrial area on the...
. An eighteen-year-old was killed in Harris County, Texas from drowning during a swim. The eight final deaths in Louisiana and Mississippi were by drowning. The extreme flooding in turn led to heavy damage, amounting to around $560 million (1989 USD, $ USD).
See also
- Other storms of the same nameTropical Storm Allison (disambiguation)The name Allison has been used for three tropical cyclones in the Atlantic Ocean and the alternative spelling Alison has been used for one tropical cyclone in the Southwest Pacific Ocean and three in the southern Indian Ocean.Atlantic...
- List of wettest tropical cyclones in the United States
- List of North Carolina hurricanes (1980–present)