Tropical Depression Ten was the tenth
tropical cycloneA tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones feed on heat released when moist air rises, resulting in condensation of water vapor contained in the moist air...
of the record-breaking
2005 Atlantic hurricane seasonThe 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, repeatedly shattering previous records. The impact of the season was widespread and ruinous with at least 2,280 deaths and record damages of over $128 billion USD...
. It formed on August 13 from a
tropical waveTropical waves, or easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of cloudiness and thunderstorms...
that emerged from the west coast of
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
on August 8. As a result of strong
wind shearWind 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...
, the depression remained weak and did not strengthen beyond tropical depression status. The cyclone degenerated on August 14, although its remnants partially contributed to the formation of Tropical Depression Twelve, which eventually intensified into
Hurricane KatrinaHurricane Katrina of the 2005 Atlantic hurricane season was the costliest hurricane, as well as one of the five deadliest, in the history of the United States...
.
Tropical Depression Ten was the tenth
tropical cycloneA tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones feed on heat released when moist air rises, resulting in condensation of water vapor contained in the moist air...
of the record-breaking
2005 Atlantic hurricane seasonThe 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, repeatedly shattering previous records. The impact of the season was widespread and ruinous with at least 2,280 deaths and record damages of over $128 billion USD...
. It formed on August 13 from a
tropical waveTropical waves, or easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of cloudiness and thunderstorms...
that emerged from the west coast of
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
on August 8. As a result of strong
wind shearWind 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...
, the depression remained weak and did not strengthen beyond tropical depression status. The cyclone degenerated on August 14, although its remnants partially contributed to the formation of Tropical Depression Twelve, which eventually intensified into
Hurricane KatrinaHurricane Katrina of the 2005 Atlantic hurricane season was the costliest hurricane, as well as one of the five deadliest, in the history of the United States...
. The cyclone had no effect on land, and did not directly result in any fatalities or damages.
Meteorological history
On August 8, a
tropical waveTropical waves, or easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of cloudiness and thunderstorms...
emerged from the west coast of
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
and entered the
Atlantic OceanThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about 106.4 million square kilometres , it covers approximately one-fifth of the Earth's surface and about one-quarter of its water surface area. The first part of its name refers to the Atlas of Greek...
. Tracking towards the west, the depression began to exhibit signs of convective organization on August 11. The system continued to develop, and it is estimated that Tropical Depression Ten formed at 1200 UTC on August 13. At the time, it was located about east of
BarbadosBarbados , situated just east of the Caribbean Sea, is an independent West Indian Continental Island-nation in the western Atlantic Ocean. For over three centuries Barbados was a colony and protectorate of the United Kingdom; and still currently maintains Queen Elizabeth II as head of state...
. Upon its designation, the depression consisted of a large area of thunderstorm activity, with curved banding features and expanding
outflowOutflow, in meteorology, is air that flows outwards from a thunderstorm. Outflow tends to indicate the "health" of a system. Large quantities of outflow at the upper levels of a thunderstorm indicate it is in good health...
. However, the environmental conditions were predicted to quickly become unfavorable. The depression moved erratically and slowly towards the west, and
wind shearWind 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...
inhabited any significant intensification. Late on August 13, it was "beginning to look like
IreneHurricane Irene was a long-lived Cape Verde-type Atlantic hurricane during the 2005 Atlantic hurricane season. The storm formed near Cape Verde on August 4 and crossed the Atlantic, turning northward around Bermuda before becoming extratropical southeast of Newfoundland. Irene persisted for...
-junior as it undergoes southwesterly mid-level shear beneath the otherwise favorable upper-level outflow pattern". The wind shear was expected to relent within 48 hours, prompting some forecast models to suggestion the depression would eventually attain hurricane status.
By early August 14, the shear had substantially disrupted the storm, leaving the low-level center of circulation exposed from the area of convection, which was also deteriorating. After meandering, the storm began to move westward. Forecasters expected it to resume a northwestward track as
high pressureA high-pressure area is a region where the atmospheric pressure at the surface of the planet is greater than its surrounding environment. Winds within high-pressure areas flow outward due to the higher density air near their center and friction with land...
to the south of
BermudaBermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, it is situated around 1,770 kilometres northeast of Miami, Florida, and 1,350 kilometres south of Halifax, Nova Scotia, Canada...
was forecasted to weaken and another high was predicted to form southwest of the
AzoresThe Azores is a Portuguese archipelago in the Atlantic Ocean, about from Lisbon and about from the east coast of North America. The two westernmost Azorean islands actually lie on the North American plate...
. By 1800 UTC on August 14, the strong shear had further weakened the storm, and it no longer met the criteria for a tropical cyclone. It degenerated into a remnant low, and the National Hurricane Center issued their final advisory on the cyclone. Moving westward, it occasionally produced bursts of convective activity, before dissipating on August 18.
Tropical Depression Twelve formed over the southeastern Bahamas at 2100 UTC on August 23, partially from the remains of Tropical Depression Ten. While the normal standards for numbering tropical depressions in the
AtlanticThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about 106.4 million square kilometres , it covers approximately one-fifth of the Earth's surface and about one-quarter of its water surface area. The first part of its name refers to the Atlas of Greek...
stipulate that the initial designation be retained when a depression regenerates, satellite imagery indicated that a second
tropical waveTropical waves, or easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of cloudiness and thunderstorms...
had combined with Tropical Depression Ten north of
Puerto RicoPuerto Rico , officially the Commonwealth of Puerto Rico , is a self-governing unincorporated territory of the United States located in the northeastern Caribbean, east of the Dominican Republic and west of the Virgin Islands...
to form a new, more complex weather system, which was then designated as Tropical Depression Twelve. In a re-analysis, it was found that the low-level circulation of Tropical Depression Ten had completely detached and dissipated; only the remnant mid-level circulation moved on and merged with the second tropical wave. As a result, the criteria for keeping the same name and identity were not met. Tropical Depression Twelve later became
Hurricane KatrinaHurricane Katrina of the 2005 Atlantic hurricane season was the costliest hurricane, as well as one of the five deadliest, in the history of the United States...
.
Impact
Because Tropical Depression Ten never approached land as a
tropical cycloneA tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones feed on heat released when moist air rises, resulting in condensation of water vapor contained in the moist air...
, no tropical cyclone watches and warnings were issued for any land masses. No effects, damages, or fatalities were reported, and no ships reported tropical storm-force winds in association with the depression. The system did not attain tropical storm status; as such, it was not designated a name by the
National Hurricane CenterThe National Hurricane Center , located at Florida International University in Miami, Florida, is the division of National Weather Service's Tropical Prediction Center responsible for tracking and predicting the likely behavior of tropical depressions, tropical storms and hurricanes.When tropical...
. The storm partially contributed to the formation of Hurricane Katrina, which would later become a
Category 5 hurricane on the
Saffir-Simpson Hurricane ScaleThe Saffir–Simpson Hurricane Scale is a classification used for most Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms. The scale divides hurricanes into five categories distinguished by the intensities of their sustained winds...
and make landfall in
LouisianaThe State of 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 divided into parishes, which are local governments equivalent to counties...
, causing catastrophic damage. Katrina was the costliest
hurricaneNorth Atlantic tropical cyclones usually form in summer or fall. Tropical cyclones can be broken down by intensity. Tropical storms have one-minute maximum sustained winds of at least 39 mph , while hurricanes have one-minute maximum sustained exceeding 74 mph...
, as well as one of the five deadliest, in the history of the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
See also
- Meteorological history of Hurricane Katrina
The meteorological history of Hurricane Katrina, an extremely destructive Category 5 hurricane, began on August 23, 2005 when it originated as Tropical Depression Twelve near the Bahamas. The next day, the tropical depression strengthened to a tropical storm, and was named Katrina; it proceeded to...
- List of storms in the 2005 Atlantic hurricane season
- Timeline of the 2005 Atlantic hurricane season
The timeline of the 2005 Atlantic hurricane season documents the formations, strengthenings, weakenings, landfalls, extratropical transitions, and dissipations of the season's tropical and subtropical storms. The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in...
External links