We’ve been monitoring #99L, an area of disturbed weather near the Bahamas for quite some time. Earlier this week, the National Hurricane Center was fairly confident that a tropical or subtropical cyclone would form here. But that tropical trouble appears to be fading somewhat; the National Hurricane Center only gives this system a 50-50 shot of becoming a cyclone.
A broad area of low pressure located a couple of hundred miles northeast of the Central Bahamas is moving slowly and erratically, but is expected to begin moving northward by tonight. Although visible satellite imagery and surface observations suggest that the low level circulation has become a little better defined since yesterday, preliminary reports from a NOAA reconnaissance aircraft indicate that the system does not have a well-defined center. In addition, the associated shower and thunderstorm activity is limited and not well organized.
This system could still become a subtropical or tropical cyclone before it merges with a cold front over the western Atlantic, well offshore of the United States east coast Friday night. Regardless of development, locally heavy rainfall along with life-threatening flash floods and mud slides are likely over portions of Hispaniola for the next day or so.
While there is that threat of flooding rains over Hispaniola, the threat of direct impacts on the US East Coast are nearly nonexistant.