State of the Climate
Hurricanes & Tropical Storms
December 2007

Tropical Storm Olga developed on the evening of December 10 from a low pressure system located near the Virgin Islands and Puerto Rico. The storm originally formed as a sub-tropical cyclone, as the cold-core, upper-level low pressure circulation intensified and a broad surface circulation became well-defined. Observations from a nearby NOAA buoy provided an initial intensity of approximately 65 km/hr (35 knots or 40 mph) on evening of the 10th. Sub-Tropical Storm Olga moved westward along the northern coast of Puerto Rico, generating heavy rainfall in the mountainous interior of the island on the 11th. Olga began to lose its sub-tropical characteristics during the morning of December 11, eventually developing a warm core and transitioning to a tropical cyclone by the evening of the 11th. Tropical Storm Olga reached its peak intensity of 93 km/hr (50 knots or 58 mph) immediately before it made landfall along the eastern coast of the Dominican Republic during the evening of December 11. The storm lost some of its organization and weakened as it slowly moved westward across the island of Hispaniola, but generated torrential rain and flooding as it interacted with the high terrain of the island. On December 12, Olga weakened considerably, and was categorized as a Tropical Depression during the afternoon. The system eventually dissipated early on the 13th. At least two dozen people lost their lives to Olga in the Caribbean. According to local officials, flash floods associated with Olga killed at least 19 people in the Dominican Republic, where 35,000 people were forced to flee their homes. The strongest winds associated with Tropical Storm Olga were 93 km/hr (50 knots or 58 mph), and its lowest pressure was 1004 mb. More information on Tropical Storm Olga is available from the NOAA National Hurricane Center.