Hurricane Danny (2003)

Hurricane Danny was the fourth named storm and second hurricane of the well-above average 2003 Atlantic hurricane season. Developing from a tropical wave at a high latitude on July 16, Danny was not expected to strengthen past minimal tropical storm intensity initially. However, as the storm followed a large loop-like path over the northern Atlantic Ocean, Danny reached hurricane intensity on July 19 at an unusually high latitude and in an area of higher than normal atmospheric pressures. After maintaining its strength for nearly 24 hours, the convection associated with the system quickly diminished as the storm moved over cooler water temperatures, and Danny degenerated to a remnant area of low pressure. The system turned to the southwest and west, and dissipated on July 27, about 630 miles (1,015 km) east of where the storm originally formed. Danny did not affect land and resulted in no injuries or fatalities.

Meteorological history
A large and well-organized tropical wave moved off the coast of Africa on July 9. However, due to cooler waters, the wave weakened as it tracked northwestward, and by the next day it was devoid of deep convection. On July 13, deep convection developed near a mid-level circulation along the wave axis, and the convection slowly organized and markedly increased over the following days. Dvorak classifications were initiated by the National Hurricane Center (NHC) late on July 15, and based on satellite imagery and ship reports of a closed surface circulation, the disturbance was designated as a tropical depression on July 16, while centered roughly 630 miles (1,015 km) east of Bermuda.

The tropical depression that became Danny was not originally anticipated to strengthen into a tropical storm. However, it quickly developed outer banding features as the convection organized, and the system strengthened into Tropical Storm Danny early on July 17. The storm moved around the western periphery of the subtropical ridge, through a narrow region of unusually high sea-surface temperatures (27 °C – 27.5 °C, 80.6 °F – 81.5 °F). This allowed for significant intensification despite Danny being located at an unusually high latitude. Based on the formation of a 17 mile (27 km) wide eye, it is estimated the storm attained hurricane status late on July 18, while located approximately 525 miles (850 km) south of St. John's, Newfoundland and Labrador. Because the system formed at such a high latitude, Danny was embedded within a higher than average surrounding pressure field, and as a result the minimum central pressure was an unusually high 1000 mbar.

Despite moving over cooler waters and into an area of higher vertical wind shear, Danny maintained minimal hurricane status for nearly 24 hours until late on July 19, when it weakened to a tropical storm. Continuing around the northern periphery of the subtropical ridge, Danny turned to the east and east-southeast into an area of even cooler waters, resulting in rapid weakening. The storm weakened into a tropical depression on July 20, and the following day, Danny degenerated into a remnant area of low pressure. Late in the forecast period as Danny was weakening, the NHC also discussed the possibility of Danny reintensifying as it moved south into a region of warmer sea-surface temperatures and less vertical wind shear. However, such a possibility was not considered likely due to the expectation that Danny would be too weak to regenerate by that point in time. The low ultimately turned southward and southwestward into an area of warmer water temperatures, and after executing a small loop on July 24, Danny developed deep convection over the center. However, a large area of dry air prevented re-development of the storm. On July 27, the remnant low dissipated about 1,240 miles (2,000 km) east of Bermuda, or about 630 miles (1,015 km) east of where tropical cyclogenesis originally took place.

Impact
Hurricane Danny did not affect any land areas and there were no reports of damage or fatalities. Early in its life, Danny moved in a direction towards Bermuda. However, a high pressure system forced the system to turn northward well to the east of the island. The hurricane entered the Canadian Hurricane Centre's response zone, although tropical storm winds were not reported in Canadian waters. The Canadian Hurricane Centre issued a gale warning for the southern half of the southeastern Grand Banks, though it was cancelled after gale force winds were no longer expected. Only one ship reported tropical storm force winds in association with Hurricane Danny; a ship on July 20 recorded a west wind of 45 mph (72 km/h) while located 105 miles (170 km) south of the center. Because Danny stayed well out to sea, no warnings or watches were issued.