Tropical Storm Tammy formed over the Atlantic Ocean east of the Lesser Antilles on Wednesday afternoon. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Tammy was located at latitude 13.0°N and longitude 51.7°W which put it about 625 miles (1005 km) east of the Lesser Antilles. Tammy was moving toward the west at 23 m.p.h. (37 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1007 mb.

Tropical Storm Watches were issued for Barbados, Dominica, Martinique and Guadeloupe.

A low pressure system over the Atlantic Ocean east of the Lesser Antilles strengthened on Wednesday afternoon and the U.S. National Hurricane Center designated the system as Tropical Storm Tammy. The circulation around Tropical Storm Tammy was not well organized. Many of the thunderstorms were occurring in bands in the eastern part of Tammy’s circulation. Bands in the western part of Tropical Storm Tammy consisted primarily of showers and lower clouds. Storms near the center of Tammy’s circulation were beginning to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) in the northeastern quadrant of Tropical Storm Tammy. The winds in the other parts of Tammy were blowing at less than tropical storm force.

Tropical Storm Tammy will move through an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 30°C. It will move under the far eastern part of an upper level low over the Eastern Caribbean Sea. The upper level low will produce southwesterly winds that will blow toward the top of Tammy’s circulation. The winds in the lower levels of the atmosphere are blowing from the east. The difference in wind direction between the upper and lower levels of the atmosphere will cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Tammy could intensify a little during the next 24 hours, if the winds in the lower levels weaken. However, if the winds in the lower levels get stronger, then Tammy could weaken to a tropical depression.

Tropical Storm Tammy will move south of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Storm Tammy could be near Barbados in 36 hours.

Tropical Storm Tammy is likely to bring gusty winds and locally heavy rain to Barbados, Dominica, Martinique and Guadeloupe. Heavy rain is likely to cause flash in some locations.