A tropical disturbance approaching the Lesser Antilles was designated Invest 96L by the National Hurricane Center (NHC). The disturbance appears to consist of a tropical wave, a broad surface low centered east of Guadaloupe and a small cyclonic meso-vortex rotating around the northeastern portion of the broader low pressure system. The overall system is moving toward the west-northwest at 21 m.p.h. There appears to be a broad area of light winds within the surface low and stronger winds on the north side of the small meso-vortex. A reconnaissance aircraft did find winds to tropical storm force on the north side of the system, but it also reported that the overall circulation was poorly defined.
This disturbance has a complicated origin which is linked to its slow development. The disturbance originally consisted of two tropical waves moving north of a broad but weak low pressure system located within the Intertropical Convergence Zone/monsoon trough. The complex structure inhibited the development of a dominant center of circulation and several clusters of thunderstorms have produced small meso-vortices like the one mentioned previously. It appears that there has been a slight increase in organization today as the broad area of low pressures appears to have a more symmetrical shape. It is unclear if an upper low to the northwest of the system is creating wind shear over the top of it.
NHC is giving a 70% chance that a tropical cyclone will form out of this system within the next five days. As broad low pressure system moves west-northwest it will affect the weather over the northeastern Caribbean Sea during the next several days. Another reconnaissance aircraft is scheduled to investigate the disturbance tomorrow afternoon, if necessary.