Tropical Storm Dorian strengthened on Wednesday morning and it was on the verge of becoming a hurricane. Hurricane Warnings were issued for Vieques, Culebra, the U.S. Virgin Islands and the British Virgin Islands. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Dorian was located at latitude 17.5°N and longitude 64.5°W which put it about 25 miles (40 km) south of St. Croix. The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 999 mb.
Hurricane Warnings were in effect for Vieques, Culebra, the U.S. Virgin Islands, and the British Virgin Islands. A Tropical Storm Warning and a Hurricane Watch was in effect for Puerto Rico. A Tropical Storm Watch was in effect for the portion of the coast of the Dominican Republic from Isla Saona to Samana.
The circulation around Tropical Storm Dorian exhibited much greater organization on Wednesday morning. A ring of strong thunderstorms wrapped almost completely around the center of circulation. The strongest winds were occurring in the northeastern part of that ring of storms. Bands of showers and thunderstorms were revolving around the core of Dorian. Storms near near the core were generating upper level divergence which was pumping mass away to the north and northeast of the tropical storm. The circulation also increased in size on Wednesday morning. Winds to tropical storm force extended out about 70 miles (110 km) from the center of circulation.
Tropical Storm Dorian will move through an environment favorable for intensification during the next few days. Dorian will move over water where the Sea Surface Temperature is near 29°C. It will move northeast of an upper level low during the next 24 hours. The low will produce some southerly winds which will blow toward the top of the circulation, but the winds will not be strong enough to prevent intensification. The wind shear will decrease on Friday and Dorian could strengthen into a major hurricane near the Bahamas.
The upper level low will help to steer Tropical Storm Dorian toward the northwest during the next 24 to 36 hours. A ridge of high pressure will build north of Dorian on Friday. The ridge will block Dorian from moving north and it will steer Dorian toward the west-northwest. On its anticipated track Tropical Storm Dorian will pass over the Virgin Islands near the eastern end of Puerto Rico today. Dorian will be near the northern Bahamas on Saturday and it could approach the east coast of Florida by Sunday night. Dorian could be a major hurricane when it approaches the east coast of the U.S.
Elsewhere over the Atlantic Ocean, former Tropical Storm Erin weakened to a tropical depression. At 11:00 a.m. EDT on Wednesday the center of Tropical Depression Erin was located at latitude 33.6°N and longitude 72.8°W which put it about 190 miles (305 km) southeast of Cape Hatteras, North Carolina. Erin was moving toward the northwest at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1006 mb.