A tropical wave located about 400 miles east-southeast of Barbados…500 miles off St Vincent in the Lesser Antilles Islands late on Tuesday morning (Invest 97L) was headed west to west-northwest at 15 – 20 mph, and appears likely to develop into a tropical depression or tropical storm later on Tuesday.
Satellite loops late Tuesday morning showed 97L did not yet have a well-defined surface circulation, though it appeared close to establishing one. The amount of heavy thunderstorm activity was modest at best, but upper-level outflow was very well established to 97L’s north.
Lack of spin from being too close to the equator was less of a problem for 97L than before, as the system had worked its way northwards to a latitude of 12°N. This is far enough from the equator for the storm to be able to leverage the Earth’s spin and acquire more spin of its own. The outermost spiral rainband of 97L was bringing rain showers to Barbados late Tuesday morning.
Invest 97L will continue west to west-northwest at 15 – 20 mph through Thursday, then slow down to a forward speed of 5 – 10 mph for the remainder of the week. The outer spiral bands of 97L will begin spreading over the Lesser Antilles Tuesday night, bringing high winds and heavy rains. The core of the storm will pass through the islands on Wednesday afternoon. It is unlikely that 97L will have time to intensify into a hurricane by then, though a strong tropical storm with 55 – 65 mph winds is quite possible.
The strongest winds and heaviest rains of 4 – 8” can be expected over the islands just north of where the center of 97L is, including the islands of St. Lucia, Martinique, Dominica, and Guadaloupe.
Source National Hurricane Center.