Tropical Depression Fifteen formed southeast of the Cabo Verde Islands on Monday. At 5:00 p.m. EDT on Monday the center of Tropical Depression Fifteen was located at latitude 13.2°N and longitude 20.2°W which put it about 320 miles (515 km) southeast of the Cabo Verde Islands. The depression was moving toward the northwest at 8 m.p.h. (13 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 1006 mb.
A large, well developed low pressure system embedded in the northern end of a tropical wave moved over the Atlantic Ocean west of North Africa on Monday. Bands of showers and thunderstorms began to strengthen when the low moved over water and the National Hurricane Center designated the system as Tropical Depression Fifteen. Bands of showers and thunderstorms were revolving around the center of the depression. Storms closer to the center were generating upper level divergence which was pumping mass away from Tropical Depression Fifteen. The circulation around the depression was quite large. The diameter of the low level circulation was about 500 miles (800 km).
Tropical Depression Fifteen will move through an environment favorable for intensification during the next 24 to 48 hours. The depression will move over water where the Sea Surface Temperature is near 28°C. It will move under the western end of an upper level ridge centered over North Africa. The upper level winds will be weak and there will be little vertical wind shear during the next day or two. Tropical Depression Fifteen is likely to strengthen into Tropical Storm Nestor.
The ridge over North Africa will steer Tropical Depression Fifteen toward the northwest during the next several days. On its anticipated track the center of the depression could reach the Cabo Verde Islands within 24 hours. Since the depression is forecast to strengthen into a tropical storm watches and/or warnings could be issued.
Elsewhere over the Atlantic Ocean, Tropical Storm Melissa completed a transition to an extratropical cyclone on Monday. At 11:00 a.m. EDT on Monday the center of Tropical Storm Melissa was located at latitude 41.0°N and longitude 51.4°W which put it about 405 miles (650 km) south-southeast of Cape Race, Newfoundland. Melissa was moving toward the east 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 1004 mb.