Tropical Storm Alpha
|Tropical Storm ( SSHWS )|
|Barahona , Dominican Republic|
|Emergence||October 22, 2005|
|resolution||October 24, 2005|
|Lowest air pressure||998 mbar ( hPa ; 29.5 inHg )|
|Haiti , Dominican Republic|
Atlantic hurricane season 2005
The tropical cyclone named Alpha originated on October 22, 2005 in the Caribbean . Since in 2005 all 21 names of the list of names had already been used for naming tropical storms and hurricanes , the Greek alphabet had to be used for the first time in the history of Atlantic cyclones.
Alpha did little damage in Hispaniola and the Bahamas , but the storm killed seventeen in Haiti and nine in the Dominican Republic . By flash floods and mudslides at least four hundred houses were damaged or destroyed in Haiti.
Alpha's origins lie in a tropical wave that formed near the Windward Islands on October 20 (Tropical Depression Twenty-five ). Satellite imagery indicated that a wave-associated low pressure center with increased convective activity was forming near Barbados . In an area of low wind shear , convection increased and data from Puerto Rico Doppler radar revealed a well-defined center of circulation. On October 22nd, the depression developed tropical characteristics and was classified as Tropical Depression 25 south of Hispaniola . Shortly afterwards, satellite images suggested that a closed circulation had developed and the associated convection had begun with the formation of rainbands.
On the evening of October 22nd, the system intensified into a tropical storm and was therefore given the name Alpha . Alpha was moving west-northwest on the southwestern edge of a subtropical ridge. Doppler radar data from Puerto Rico suggested that an eyewall-like feature had formed. Due to the proximity of Hurricane Wilma's large circulation, Alpha experienced abundant southward discharge. Alpha with its small circulation then got over the mountainous terrain of Hispaniola, which is why the meteorologists assumed that the storm would soon disperse. On October 23, the system reached its greatest strength with wind speeds of up to around 85 km / h and gust peaks of around 100 km / h, and shortly afterwards the wind speeds decreased again. Due to the influence of the island, the convective band structures were retained, but the circulation center near the ground was quite disturbed, so that it was difficult to locate.
Late on October 23, Alpha landed near the city of Barahona in the Dominican Republic with sustained one-minute winds of 80 km / h. After that, the storm quickly lost its intensity and because of the existing outflow from Hurricane Wilma, it was difficult to decide whether a closed circulation was still available. However, satellite images showed that a new center of circulation had formed over water north of Hispaniola. Early the next day the storm was downgraded to a tropical depression that was now completely over open water. The system soon formed an elongated center of circulation, which was a sign of the weakening. On October 24th, the near-surface circulation had completely dissolved and only a small part of the convective activity remained, so the National Hurricane Center issued the final warning about the residual low alpha. This residual low was absorbed by Wilma's circulation on October 25th.
Name and records
Since all predetermined names were used up after Hurricane Wilma , a Greek letter was used for the first time to designate a tropical storm. However, Alpha had already been used for a subtropical storm in the 1972 Atlantic hurricane season .
During operations, it was assumed that Alpha was the 22nd storm of the season and thus the storm that broke the previous record for most storms in an Atlantic hurricane season. This was set up in the 1933 hurricane season . The follow-up analysis revealed that a previously neglected subtropical storm had formed on October 4, 2005 , making Alpha the 23rd storm of the season.
- National Hurricane Center Archives on Tropical Storm Alpha
- Tropical Cyclone Report from the National Hurricane Center on Tropical Storm Alpha
- Storm Alpha , in Thomas Sävert: Forces of Nature
- Lixion Avila: Tropical Storm Alpha Tropical Cyclone Report ( English , PDF) National Hurricane Center. January 4, 2006. Retrieved February 22, 2014.
- Roberts / Knabb: Tropical Depression 25 Public Advisory # 1 ( English ) National Hurricane Center. October 22, 2005. Retrieved April 22, 2014.
- Roberts / Knabb: language = English Tropical Depression 25 Discussion # 1 . National Hurricane Center. October 22, 2005. Retrieved January 25, 2008.
- Mainelli / Knabb: Tropical Storm Alpha Public Advisory # 2 ( English ) National Hurricane Center. October 22, 2005. Retrieved April 22, 2014.
- Franklin: Tropical Storm Alpha Discussion # 3 ( English ) National Hurricane Center. October 22, 2005. Retrieved April 22, 2014.
- Franklin: Tropical Storm Alpha Discussion # 4 ( English ) National Hurricane Center. October 23, 2005. Retrieved April 22, 2014.
- Avila: Tropical Storm Alpha Discussion # 5 ( English ) National Hurricane Center. October 23, 2005. Retrieved January 25, 2008.
- Avila: Tropical Storm Alpha Discussion # 6 ( English ) National Hurricane Center. October 23, 2005. Retrieved April 23, 2014.
- Rhome / Stewart: Tropical Depression Alpha Discussion # 7 ( English ) National Hurricane Center. October 23, 2005. Retrieved January 25, 2008.
- Stewart: Tropical Storm Alpha Discussion # 8 ( English ) National Hurricane Center. October 24, 2005. Retrieved January 25, 2008.
- Beven: Tropical Depression Alpha Discussion # 9 ( English ) National Hurricane Center. October 24, 2005. Retrieved April 22, 2014.
- Jeff Hecht: Wilma hits Florida, Alpha breaks record ( English ) NewScientist.com news service. October 24, 2005. Retrieved April 22, 2014.
- National Hurricane Center: Tropical Cyclone Report: Unnamed Subtropical Storm ( English , PDF) NOAA. April 10, 2006. Retrieved April 22, 2014.