Tropical Storm Arlene (1999)

Tropical Storm Arlene was the first tropical cyclone of the 1999 Atlantic hurricane season. Arlene formed on June 11 from the interaction between a mid/upper level low that previously detached itself from a frontal system. It was classified as a tropical depression despite a cold-core, which would normally indicate subtropical characteristics. By the next day, the tropical depression had been upgraded to Tropical Storm Arlene, the first of the season. Tropical Storm Arlene remained nearly stationary for much of its duration. The storm attained its peak intensity as a 60 mph tropical storm on June 13. Fluctuating slightly in intensity and still nearly stationary, Arlene also executed a small cyclonic loop on June 15. Thereafter, Tropical Storm Arlene started to weaken as it began to encounter unfavorable conditions, mainly increasing wind shear and lower water temperatures. On the day of June 17, Tropical Storm Arlene was downgraded back to a tropical depression. That same day, Tropical Depression Arlene would also pass about 100 miles (160 km) to the east of Bermuda. Thought it was initially feared that Tropical Storm Arlene would approach the island much closer. Wind shear continued to affect Tropical Depression Arlene, and by June 18, it had dissipated. The remnants of Tropical Depression Arlene would turn northeast and remain out at sea.

Arlene briefly posed a threat to Bermuda, thought it veered away and weakened. This tropical storm was the first named Atlantic storm to form in the month of June since Tropical Storm Arthur in 1996, it would remain so until Tropical Storm Allison formed in 2001. Arlene was also forecast to briefly attain hurricane status. Tropical Storm Arlene did not affect any landmass, despite coming within 100 mi of Bermuda.

Meteorological History
A mid/upper level low emerged from a diffused front on June 8. This low was located several hundred miles north of Puerto Rico. Around this time, a tropical wave passed near the low. Over the next two days, the low level cloud swirl did not significantly develop, as wind shear was present. Convection began to gather near the center as wind shear was decreasing because of an upper level low moving away. It was estimated that by June 11 the low had strengthened into a tropical depression, therefore becoming Tropical Depression One, while it was centered about 345 mi from Bermuda. The newly formed depression drifted to the west for nearly 24 hours. On June 12 the National Hurricane Center upgraded the depression to a tropical storm, it was assigned to the name Arlene.

Tropical Storm Arlene reached peak intensity on June 13, wind were at 60 mph and a barometric pressure of 1006 mbar (hPa; 29.71 inHg). In the following days, Tropical Storm Arlene's intensity fluctuated, slightly. The tropical storm executed a small cyclonic loop on June 15. After this, wind shear began to increase, while water temperatures decreased, causing Arlene to weaken. On June 17, Tropical Storm Arlene was downgraded back to a tropical depression. Shortly after weakening to a depression, Arlene passed about 100 mi east of Bermuda. Wind shear persisted, and finally, on June 18, Arlene dissipated. The system was absorbed by a frontal zone about 280 mi north-north east of Bermuda.

Impact
Arlene was a brief threat to Bermuda, however, it passed 100 mi away from Bermuda, while it was forecast to come within 60 mi. Because of the operational prediction, a tropical storm watch was issued for the entire island of Bermuda on June 14. This watch was replaced by a tropical storm warning on June 16, as Arlene approached. The warning was discontinued on June 17 as Arlene weakened and veered away. Tropical Storm Arlene did not approach Bermuda close enough to bring tropical storm force winds to the island.