Though still not officially a Depression, the easterly wave we've been watching closely is now passing north of Barbuda and toward the Virgin Islands. You can view a radar loop of the forming storm from the Guadeloupe radar at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/fay08/Fay_14Aug08.gif
It has entered the phase where it can intensify rather quickly, a phase visually triggered by the development of a persistent CDO, or cold dense overcast. On an infrared satellite loop, this looks like a shield over the center, with very cold cloud-top temperatures, roughly -75C in this case.
Under this dense cloud shield aloft, a core of intense thunderstorms is organizing, perhaps even into an early eyewall (see radar loop above).
Current intensity is estimated at 30kts and 1009mb, and tracking WNW at 12kts. The forecast is looking more and more ominous for the US, and first, the Bahamas. Computer models indicate a track directly over the Bahamas, maybe as a CAT1 hurricane this weekend. By early-mid next week, the southeast US coast should be on alert... from FL to NC. There is a smaller possibility that it could slip south of Florida and cross into the Gulf. The forecast track will of course be closely scrutinized in the coming days.
The next number/name on deck is 6/Fay.
Elsewhere, an impressive easterly wave has just exited the African coast and is just south of the Cape Verdes now. Several long-range models develop this into a hurricane within a week.
Please visit my tropical Atlantic headquarters.