Stronger Tropical Storm Dorian Causes Warnings for Lesser Antilles

Tropical Storm Dorian strengthened on Sunday and the threat it posed caused warnings and watches to be issued for some of the Lesser Antilles.  Tropical Storm Warnings were in effect for Barbados, St. Lucia, and St. Vincent and the Grenadines.  Tropical Storm Watches were issued for Grenada and Martinique.

At 5:00 p.m. EDT on Sunday the center of Tropical Storm Dorian was located at latitude 11.5°N and longitude 54.2°W which put it about 375 miles (605 km) east-southeast of Barbados.  Dorian was moving a little to the north of due west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1003 mb.

The circulation around Tropical Storm Dorian exhibited greater organization on Sunday afternoon.  The inner end of a band of showers and thunderstorms wrapped tightly around the northern and western sides of the center of circulation.  The strongest winds were occurring in that band.  Several other bands of showers and storms were revolving around the small core of Dorian.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the north of the tropical storm.  The circulation around Tropical Storm Dorian was small.  Winds to tropical storm force extended out about 35 miles (55 km) from the center of circulation.

Tropical Storm Dorian will move through an environment mostly favorable for intensification.  Dorian will move over water where the Sea Surface Temperature is near 28.5°C.  It will move through a region where the upper level winds are relatively weak and there will be little vertical wind shear.  A large area of drier air is north of Tropical Storm Dorian.  If the circulation draws drier air into the tropical storm, it would interrupt intensification.  Tropical Storm Dorian is likely to strengthen during the next 24 to 48 hours.  Since Dorian has a small circulation, it could intensify or weaken quickly if the environmental conditions change.

Tropical Storm Dorian will move south of the subtropical high pressure system over the North Atlantic Ocean.  The high will steer Dorian toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Dorian could approach Barbados late on Monday.  It could be a hurricane by that time.  Dorian could reach the southern and central Lesser Antilles on Tuesday.  Tropical Storm Dorian could bring strong winds and heavy rain to those islands.