Tropical Storm Sebastien sped eastward across the Atlantic Ocean on Friday. At. 4:00 p.m. EST on Friday the center of Tropical Storm Sebastien was located at latitude 26.2°N and longitude 53.7°W which put it about 815 miles (1315 km) northeast of the Leeward Islands. Sebastien was moving toward the east-northeast at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 999 mb.
An upper level trough over the western Atlantic Ocean was producing strong southwesterly winds which were blowing toward the top of Tropical Storm Sebastien. Those winds were producing moderate vertical wind shear. The shear was contributing to an asymmetrical distribution of thunderstorms around Sebastien. Stronger thunderstorms were occurring in bands north and east of the center of circulation. Bands south and west of the center consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (325 km) from the center of circulation.
Tropical Storm Sebastien will move through an environment that could permit it to maintain its intensity for another day or so. Sebastien will move over water where the Sea Surface Temperature is near 25.5°C. The upper level trough over the western Atlantic will continue to cause moderate vertical wind shear, which will inhibit intensification. Sebastien will move over cooler water during the weekend and it should start to weaken at that time.
The upper level trough will steer Tropical Storm Sebastien toward the northeast during the weekend. On its anticipated track Sebastien will move toward the Azores. Sebastien is forecast to merge with a cold front before it reaches the Azores.