The risk posed by Tropical Storm Melissa prompted the issuance of a Hurricane Watch for Jamaica on Thursday morning.  A Tropical Storm Warning was also issued for Jamaica.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Melissa was located at latitude 15.4°N and longitude 74.9°W which put the center about 220 miles (355 km) southeast of Kingston, Jamaica.  Melissa was moving toward the north-northwest at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1003 mb.

A Hurricane Watch is in effect for Jamaica.

A Hurricane Watch is also in effect for the southern coast of Haiti from the border with the Dominican Republic to Port Au Prince.

A Tropical Storm Warning is in effect for Jamaica.

Tropical Storm Melissa was showing indications of becoming more organized on Thursday morning.  The inner end of a rainband wrapped around the western side of the center of Melissa’s circulation.  More thunderstorms developed in bands in the eastern side of Tropical Storm Melissa.  Bands in the western side of Melissa’s circulation still consisted primarily of showers and lower clouds.  Storms near the center of Melissa generated upper level divergence that pumped mass away to the east of the tropical storm.

Vertical wind shear caused the distribution of wind speeds in Tropical Storm Melissa to continue to be asymmetrical.  Winds to tropical storm force extended out 115 miles (185 km) in the eastern half of Melissa’s circulation.  Winds to tropical storm force extended out 70 miles (110 km) in the northwestern quadrant of Tropical Storm Melissa.  The winds in the southwestern quadrant of Melissa’s circulation were blowing at less than tropical storm force.

Tropical Storm Melissa will move through an environment that will become more favorable for intensification during the next 24 hours.  Melissa will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southeastern part of an upper level trough that is over Cuba.  The upper level trough will produce southwesterly winds that will blow toward the top of Melissa’s circulation.  Those winds will produce moderate vertical wind shear, but the winds will get weaker during the next 24 hours.  The moderate vertical wind shear will inhibit intensification, but the wind shear will decrease on Friday.  Tropical Storm Melissa could start to intensify during the next 24 hours.

Tropical Storm Melissa will move around the western end of a high pressure system that is over the Atlantic Ocean.  The high pressure system will steer Melissa slowly toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Melissa will continue to move slowly toward Jamaica.