Tropical Depression Eleven Forms East of the Windward Islands

Tropical Depression Eleven formed east of the Windward Islands on Friday night.  At 11:00 p.m. EDT on Friday the center of Tropical Depression Eleven was located at latitude 13.1°N and longitude 53.4°W which put it about 510 miles (825 km) east of the Windward Islands.  It was moving toward the west-northwest at 6 m.p.h. (10 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 1007 mb.

A small circular low pressure system within a tropical wave has been moving westward toward the Windward Islands.  An upper level trough near the eastern Caribbean Sea has been producing southwesterly winds which blowing across the top of the low.  Those winds were producing significant vertical wind shear and they were preventing taller thunderstorms from persisting near the center of circulation.  The National Hurricane Center decided that the low pressure system possessed sufficient convection to be classified as a Tropical Depression at 11:00 p.m.. EDT on Friday night.

The distribution of thunderstorms around Tropical Depression Eleven was still asymmetrical because of the wind shear caused by the upper level trough.  There was a well defined, but small, low level circulation with a distinct center.  Most of the bands around the center of circulation consisted of showers and lower clouds.  There were stronger thunderstorms in some of the bands east of the center of circulation.

Tropical Depression Eleven will move through an environment somewhat favorable for intensification.  It will move over water where the Sea Surface Temperature is near 29°C.  The upper level trough will continue to cause significant vertical wind shear.  The wind shear will limit the potential for intensification.  Tropical Depression Eleven could strengthen into a tropical storm, but rapid intensification is not likely.  However, small tropical cyclones can strengthen or weaken very rapidly if the environment around them changes.

Tropical Depression Eleven will move south of the subtropical high pressure system over the Atlantic Ocean.  The high will steer the depression in a west-northwesterly direction.  On its anticipated track the center of Tropical Depression Eleven could be east of the Lesser Antilles on Sunday night.