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Tropical Storm Alpha (2005)
Encyclopedia
Tropical Storm Alpha was the twenty-third named storm of the 2005 Atlantic hurricane season
. The twenty-one names from the predetermined A–W list having been used, Alpha was the first tropical storm ever to be given a name from the Greek alphabet. On October 20, Tropical Depression Twenty-five formed from a tropical wave near the Windward Islands
. It became a tropical storm on October 23, and reached its peak intensity but weakened again before making landfall in the Dominican Republic
that afternoon. Crossing the island of Hispaniola
it weakened to a tropical depression, and persisted until October 24, when it dissipated. Its remnant low
was absorbed by Hurricane Wilma
's large circulation.
Alpha dumped torrential rain on the island of Hispaniola, making it the eighth wettest storm to impact poverty-stricken Haiti
. It caused 26 deaths, 17 of them in Haiti and all of them caused by floods and rain-related landslides. Roads were blocked for weeks and hundreds of houses were destroyed.
and moved west-northwest with increasing convective activity. In an area of light wind shear
, the convection increased and Doppler weather radar data from Puerto Rico detected a well-defined cyclonic circulation
. On October 22, the area of low pressure organized into Tropical Depression 25, southeast of Hispaniola
. Shortly thereafter, satellite imagery indicated that a closed circulation had developed, and the associated convection had started banding. Later that same day, the depression had organized enough to be upgraded to Tropical Storm Alpha; this was the first time the National Hurricane Center
had to use a Greek name for an Atlantic hurricane.
When Alpha came within the Doppler weather radar range of Puerto Rico
, the radar suggested that an eyewall-like feature had developed. Alpha was tracking along the southwest edge of a subtropical ridge. With nearby Hurricane Wilma's large circulation, Alpha was experiencing strong southerly flow from Wilma. Alpha, with its small circulation, was then faced with the mountainous terrain of Hispaniola, which led forecasters to believe Alpha was soon to dissipate. Shortly after Alpha reached its peak intensity on October 23 its wind decreased. While convection remained in bands, the low level circulation was disrupted by land. This left the center ill-defined and difficult to locate.
Late on October 23, Alpha made landfall in Hispaniola, quickly decreasing in intensity as it did so. After making landfall, the storm weakened, leaving it just between tropical storm and tropical depression status. Because of the weakening, and the strong southerly flow from nearby Hurricane Wilma, it was hard to determine whether a low-level circulation was present. However, satellite imagery suggested that a new center had developed over open waters to the north of Hispaniola. It was downgraded to a tropical depression early the next day, now re-emerging over open waters. The storm soon developed an elongated center of circulation which indicated that the system was weakening. On October 24 the low-level center had completely dissolved, and only a small area of convective activity
persisted. Thus the system had dissipated, and was a remnant low pressure system when the National Hurricane Center issued their last advisories of Alpha. Shortly thereafter, the remnant low was absorbed into the circulation of Hurricane Wilma on October 25.
for the island of Hispaniola and a tropical storm watch for Turks and Caicos Islands
and the southeastern Bahamas. The tropical storm watch was quickly upgraded to a tropical storm warning. In the Dominican Republic, authorities ordered the evacuation of at least 30,000 people living in areas where flooding was possible. On October 22 and 23, the Haitian government ordered level 1 and then level 2 alerts for the county in anticipation of Tropical Storm Alpha's rainfall. Haiti was already experiencing flooding from Hurricane Wilma's passage between October 8 and 19, so the threat of more rainfall was particularly dire. The country's Centre National de Meteorologie issued weather bulletins through existing media distribution channels with clear instructions on how residences should prepare for floods and landslides. The local government of the Sud-Est Department
ordered the evacuation of its capital city, Jacmel
. The national government mobilized personnel and resources of the Direction of Civil Protection, the Secrétariat Permanent de Gestion des Risques et des Désastres (SPGRD), and the National Police to pre-arranged Emergency Operation Centres.
in the Dominican Republic, the bulk of its impact occurred in the country's poorer neighbor, Haiti. When Alpha arrived on Hispaniola it brought between 4 inches (101 mm) and 7.9 in (201 mm) of rain which triggered floods and landslides. The road between Port-au-Prince
and the Haiti's Sud Department
was closed at Grand-Goâve in the Ouest Department
. In the coastal city of Léogâne
near Port-au-Prince, bridges were closed to cars but not to pedestrians. Surging rivers east of Marigot
and west of Jacmel closed roads in that region, and the main road between Jérémie
and Les Cayes
was also closed. Elsewhere in the country, landslides temporarily blocked several other major roads. Gonâve Island
, which had been suffering a brutal drought, was stricken by floods which overwhelmed and washed away pipes of the water draining system
in Nan Baré.
Damages in Haiti were mostly confined to the Ouest, Sud-Est, and Grand'Anse
departments. In Haiti, 17 people died. Two drowned when a river overflowed in Grande Anse and two more died after being electrocuted during flooding, one in the Port-au-Prince suburb of Carrefour and the other in the southern town of Jacmel. The rest of the deaths were the results of landslides and flooding in various areas in the country. Across the country, 243 houses were destroyed, and 191 more were damaged.
Nine people were killed in the Dominican Republic: two fishermen went missing at sea during the storm and the others were swept away by flood waters when rivers burst their banks in Guaricanos and Puerto Plata. Otherwise, the damage in the Dominican Republic was minimal.
The Haitian government did not request international assistance, although The United Nations Stabilization Mission in Haiti (MINUSTAH), the United Nations Development Programme (UNDP) and the Haitian Red-Cross, which were already working in Haiti, took on some supporting roles. In response to local flooding, the Jacmel Regional branch of the Red Cross distributed an additional 400 water purification tablets, 11 boxes of high-energy biscuits
, and 10 boxes of body soap.
once it reached tropical storm status. The name Alpha had been used before in the Atlantic for a subtropical storm, but 2005 was the first season to have a tropical storm Alpha.
At the time it was thought that Alpha was the twenty-second storm of the season, and so was the storm which broke the 1933 season
's record for most storms in a single season. However post-season analysis revealed that there was also a previously unnoticed subtropical storm
on October 4, which made Alpha the twenty-third storm of the season. Alpha was the first tropical storm to be assigned a Greek-alphabet name after the list of hurricane names was exhausted.
The NHC's archive on Tropical Storm Alpha.
The NHC's Tropical Cyclone Report
2005 Atlantic hurricane season
The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, repeatedly shattering numerous records. The impact of the season was widespread and ruinous with an estimated 3,913 deaths and record damage of about $159.2 billion...
. The twenty-one names from the predetermined A–W list having been used, Alpha was the first tropical storm ever to be given a name from the Greek alphabet. On October 20, Tropical Depression Twenty-five formed from a tropical wave near the Windward Islands
Windward Islands
The Windward Islands are the southern islands of the Lesser Antilles, within the West Indies.-Name and geography:The Windward Islands are called such because they were more windward to sailing ships arriving in the New World than the Leeward Islands, given that the prevailing trade winds in the...
. It became a tropical storm on October 23, and reached its peak intensity but weakened again before making landfall in the Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
that afternoon. Crossing the island of Hispaniola
Hispaniola
Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...
it weakened to a tropical depression, and persisted until October 24, when it dissipated. Its remnant low
Low pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...
was absorbed by Hurricane Wilma
Hurricane Wilma
Hurricane Wilma was the most intense tropical cyclone ever recorded in the Atlantic basin. Wilma was the twenty-second storm , thirteenth hurricane, sixth major hurricane, and fourth Category 5 hurricane of the record-breaking 2005 season...
's large circulation.
Alpha dumped torrential rain on the island of Hispaniola, making it the eighth wettest storm to impact poverty-stricken Haiti
Haiti
Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...
. It caused 26 deaths, 17 of them in Haiti and all of them caused by floods and rain-related landslides. Roads were blocked for weeks and hundreds of houses were destroyed.
Meteorological history
Alpha's origins were from a tropical wave that developed near the Windward Islands on October 20. Satellite images indicated that a low pressure center associated with the tropical wave formed near BarbadosBarbados
Barbados is an island country in the Lesser Antilles. It is in length and as much as in width, amounting to . It is situated in the western area of the North Atlantic and 100 kilometres east of the Windward Islands and the Caribbean Sea; therein, it is about east of the islands of Saint...
and moved west-northwest with increasing convective activity. In an area of light 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...
, the convection increased and Doppler weather radar data from Puerto Rico detected a well-defined cyclonic circulation
Cyclone
In meteorology, a cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale...
. On October 22, the area of low pressure organized into Tropical Depression 25, southeast of Hispaniola
Hispaniola
Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...
. Shortly thereafter, satellite imagery indicated that a closed circulation had developed, and the associated convection had started banding. Later that same day, the depression had organized enough to be upgraded to Tropical Storm Alpha; this was the first time the National Hurricane Center
National Hurricane Center
The National Hurricane Center , located at Florida International University in Miami, Florida, is the division of the National Weather Service responsible for tracking and predicting weather systems within the tropics between the Prime Meridian and the 140th meridian west poleward to the 30th...
had to use a Greek name for an Atlantic hurricane.
When Alpha came within the Doppler weather radar range of Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
, the radar suggested that an eyewall-like feature had developed. Alpha was tracking along the southwest edge of a subtropical ridge. With nearby Hurricane Wilma's large circulation, Alpha was experiencing strong southerly flow from Wilma. Alpha, with its small circulation, was then faced with the mountainous terrain of Hispaniola, which led forecasters to believe Alpha was soon to dissipate. Shortly after Alpha reached its peak intensity on October 23 its wind decreased. While convection remained in bands, the low level circulation was disrupted by land. This left the center ill-defined and difficult to locate.
| Country | Total deaths | |||||
|---|---|---|---|---|---|---|
| Dominican Republic Dominican Republic The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries... |
9 | |||||
| Haïti Haiti Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island... |
17 | |||||
| Totals | 26 | |||||
| Source: The NHC's Tropical Cyclone Report | ||||||
Late on October 23, Alpha made landfall in Hispaniola, quickly decreasing in intensity as it did so. After making landfall, the storm weakened, leaving it just between tropical storm and tropical depression status. Because of the weakening, and the strong southerly flow from nearby Hurricane Wilma, it was hard to determine whether a low-level circulation was present. However, satellite imagery suggested that a new center had developed over open waters to the north of Hispaniola. It was downgraded to a tropical depression early the next day, now re-emerging over open waters. The storm soon developed an elongated center of circulation which indicated that the system was weakening. On October 24 the low-level center had completely dissolved, and only a small area of convective activity
Convection
Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....
persisted. Thus the system had dissipated, and was a remnant low pressure system when the National Hurricane Center issued their last advisories of Alpha. Shortly thereafter, the remnant low was absorbed into the circulation of Hurricane Wilma on October 25.
Preparations
On October 22, the National Hurricane Center issued a tropical storm warningTropical cyclone warnings and watches
Warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate...
for the island of Hispaniola and a tropical storm watch for Turks and Caicos Islands
Turks and Caicos Islands
The Turks and Caicos Islands are a British Overseas Territory and overseas territory of the European Union consisting of two groups of tropical islands in the Caribbean, the larger Caicos Islands and the smaller Turks Islands, known for tourism and as an offshore financial centre.The Turks and...
and the southeastern Bahamas. The tropical storm watch was quickly upgraded to a tropical storm warning. In the Dominican Republic, authorities ordered the evacuation of at least 30,000 people living in areas where flooding was possible. On October 22 and 23, the Haitian government ordered level 1 and then level 2 alerts for the county in anticipation of Tropical Storm Alpha's rainfall. Haiti was already experiencing flooding from Hurricane Wilma's passage between October 8 and 19, so the threat of more rainfall was particularly dire. The country's Centre National de Meteorologie issued weather bulletins through existing media distribution channels with clear instructions on how residences should prepare for floods and landslides. The local government of the Sud-Est Department
Sud-Est Department
Sud-Est is one of the ten departments of Haiti. It has an area of 2,023 km² and a population of 518,200 . Its capital is Jacmel...
ordered the evacuation of its capital city, Jacmel
Jacmel
Jacmel, also known by its indigenous Taíno name of Yaquimel, is a town in southern Haiti founded in 1698. It is the capital of the department of Sud-Est and has an estimated population of 40,000, while the municipality of Jacmel had a population of 137,966 at the 2003 Census.The buildings are...
. The national government mobilized personnel and resources of the Direction of Civil Protection, the Secrétariat Permanent de Gestion des Risques et des Désastres (SPGRD), and the National Police to pre-arranged Emergency Operation Centres.
Impact
Although the storm's circulation technically made landfall near BarahonaSanta Cruz de Barahona
Barahona, also known as Santa Cruz de Barahona, is the main city of the Barahona Province, in the south of the Dominican Republic. It is one of the most important cities on the island, with a very active port and many ecotourism attractions...
in the Dominican Republic, the bulk of its impact occurred in the country's poorer neighbor, Haiti. When Alpha arrived on Hispaniola it brought between 4 inches (101 mm) and 7.9 in (201 mm) of rain which triggered floods and landslides. The road between Port-au-Prince
Port-au-Prince
Port-au-Prince is the capital and largest city of the Caribbean nation of Haiti. The city's population was 704,776 as of the 2003 census, and was officially estimated to have reached 897,859 in 2009....
and the Haiti's Sud Department
Sud Department
Sud is one of the ten departments of Haiti. It has an area of and a population of 745,000 . Its capital is Les Cayes. A large part of the population of Haitians in this department is of mixed race, mulattoes along with other mixtures such as Arabs and East Indians...
was closed at Grand-Goâve in the Ouest Department
Ouest Department
Ouest is one of the ten departments of Haiti. It is the jurisdictional seat of the national capital, the city of Port-au-Prince. It has an area of and a population of 3,093,698 . It borders the Dominican Republic to the east.It is the second largest department in Haiti after the Artibonite...
. In the coastal city of Léogâne
Léogane
Léogâne is a seaside town in Ouest Department, Haïti. It is located in the eponymous arrondissement, the Léogâne Arrondissement. The port town is located about West of the Haitian capital, Port-au-Prince. The town was at the epicenter of the 12 January 2010 earthquake, and was catastrophically...
near Port-au-Prince, bridges were closed to cars but not to pedestrians. Surging rivers east of Marigot
Marigot, Sud-Est
Marigot is a municipality in the Jacmel Arrondissement, in the Sud-Est Department of Haiti.It has 50,734 inhabitants....
and west of Jacmel closed roads in that region, and the main road between Jérémie
Jérémie
Jérémie is the capital city of the department of Grand'Anse, in Haiti, with a population of about 31,000 . It is almost isolated from the rest of the country...
and Les Cayes
Les Cayes
Les Cayes , is a town and seaport in southwestern Haiti, with a population of approximately 45,904 people . Estimates from 2008 place the population at close to 70,000 people...
was also closed. Elsewhere in the country, landslides temporarily blocked several other major roads. Gonâve Island
Gonâve Island
Gonâve Island is an island of Haiti located to the west-northwest of Port-au-Prince in the Gulf of Gonâve. It is the largest of the Hispaniolan satellite islands, situated off the mainland...
, which had been suffering a brutal drought, was stricken by floods which overwhelmed and washed away pipes of the water draining system
in Nan Baré.
Damages in Haiti were mostly confined to the Ouest, Sud-Est, and Grand'Anse
Grand'Anse Department
Grand'Anse is one of the ten administrative departments of Haiti. Its capital is Jérémie.-History:...
departments. In Haiti, 17 people died. Two drowned when a river overflowed in Grande Anse and two more died after being electrocuted during flooding, one in the Port-au-Prince suburb of Carrefour and the other in the southern town of Jacmel. The rest of the deaths were the results of landslides and flooding in various areas in the country. Across the country, 243 houses were destroyed, and 191 more were damaged.
Nine people were killed in the Dominican Republic: two fishermen went missing at sea during the storm and the others were swept away by flood waters when rivers burst their banks in Guaricanos and Puerto Plata. Otherwise, the damage in the Dominican Republic was minimal.
The Haitian government did not request international assistance, although The United Nations Stabilization Mission in Haiti (MINUSTAH), the United Nations Development Programme (UNDP) and the Haitian Red-Cross, which were already working in Haiti, took on some supporting roles. In response to local flooding, the Jacmel Regional branch of the Red Cross distributed an additional 400 water purification tablets, 11 boxes of high-energy biscuits
High Energy Biscuits
High Energy Biscuits are wheat biscuits containing high-protein cereals and vegetable fat. Because of their high energy-to-weight ratio they are procured by the World Food Programme, the food aid branch of the United Nations, for feeding disaster victims worldwide.HEBs have been provided to a...
, and 10 boxes of body soap.
Naming and records
Since all the twenty one predetermined hurricane names were exhausted after Hurricane Wilma, the Greek alphabet was used and the storm was designated AlphaAlpha (letter)
Alpha is the first letter of the Greek alphabet. In the system of Greek numerals it has a value of 1. It was derived from the Phoenician letter Aleph...
once it reached tropical storm status. The name Alpha had been used before in the Atlantic for a subtropical storm, but 2005 was the first season to have a tropical storm Alpha.
At the time it was thought that Alpha was the twenty-second storm of the season, and so was the storm which broke the 1933 season
1933 Atlantic hurricane season
The 1933 Atlantic hurricane season was the second most active Atlantic hurricane season on record, with 21 storms forming during that year in the northwest Atlantic Ocean. The season ran through the summer and the first half of fall in 1933, and was surpassed in total number of tropical cyclones by...
's record for most storms in a single season. However post-season analysis revealed that there was also a previously unnoticed subtropical storm
2005 Azores subtropical storm
The 2005 Azores subtropical storm was the nineteenth nameable storm of the record-breaking 2005 Atlantic hurricane season. It was not officially named by the National Hurricane Center as it was operationally classified as a non-tropical low. The storm developed in the eastern Atlantic Ocean out of...
on October 4, which made Alpha the twenty-third storm of the season. Alpha was the first tropical storm to be assigned a Greek-alphabet name after the list of hurricane names was exhausted.
See also
- List of tropical cyclones
- List of Atlantic hurricanes
- List of 2005 Atlantic hurricane season storms
- Timeline of the 2005 Atlantic hurricane seasonTimeline of the 2005 Atlantic hurricane seasonThe 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...