Tag Archives: Greater Antilles

Invest 94L Likely to Develop East of Lesser Antilles

A tropical disturbance currently designated as Invest 94L is likely to develop into a tropical cyclone east of the Lesser Antilles.  The National Hurricane Center’s probability of formation of a tropical cyclone from this system during the next five days is 70%.  At 2:00 p.m. EDT on Monday the center of Invest 94L was located at latitude 8.7°N and longitude 32.7°W which put it about 1830 miles (2950 km) east of the Lesser Antilles.  It was moving toward the west at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1011 mb.

Invest 94L consists of a broad area of low pressure, but it has not developed a well organized inner core.  The initial area of low pressure consisted of a counterclockwise rotation associated with a tropical wave that moved over the eastern Atlantic Ocean.  The initial low slowed down as it was moving westward and a second tropical wave caught up to it.  The thunderstorms from the two waves appear to be merging into a single system.  An area of showers and thunderstorms on the northern and western sides of the surface low was part of the first tropical wave.  Other bands of showers and thunderstorms south and east of the low are associated with the second tropical wave.  If the broad low pressure system can collect the rotation from the two tropical waves, it could strengthen the surface low.

Invest 94L will move through an environment that will be favorable for the development of a tropical cyclone.  It will move over water where the Sea Surface Temperature (SST) is near 28°C.  There are easterly winds blowing at multiple levels in the atmosphere and there is little vertical winds shear.  The existence of a surface low pressure system, warm SSTs and little vertical wind shear are the primary ingredients for the development of a tropical cyclone.  That is the reason why there is strong probability that Invest 94L will develop into a tropical depression or a tropical storm.

Invest 94L will be steered by the subtropical high pressure system over the Atlantic Ocean.  A general westerly or west-northwesterly track is forecast during the next few days.  There is still significant uncertainty about the ultimate track and intensity of this system beyond that time frame.  It will need to be monitored closely as it moves west.