Tropical Storm Alpha (2005)

Tropical Storm Alpha

Tropical storm (SSHWS/NWS)
Tropical Storm Alpha a few hours after landfall in Dominican Republic on October 24
Formed	October 22, 2005
Dissipated	October 24, 2005
Highest winds	1-minute sustained: 50 mph (85 km/h)
Lowest pressure	998 mbar (hPa); 29.47 inHg
Fatalities	26 total
Damage	Unknown
Areas affected	Hispaniola
Part of the 2005 Atlantic hurricane season

Tropical Storm Alpha was the twenty-third named storm of the record-breaking 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.

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 Barbados 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.