The Air Force Hurricane Hunter mission investigating the tropical wave near Puerto Rico did not find a closed circulation indicating a tropical depression had formed this afternoon, which is not surprising given the sparse cloud cover associated with this system. Still, the cloud pattern does show a good degree of organization and upper-level winds are still favorable, so a tropical depression could form tomorrow morning. The timing of formation will be critical. If the storm just gets its act together as it hits Hispanolia, will it be able to survive crossing the island and reform on the other side? I've never seen a tropical depression try to form basically on top of Hispanolia, which appears as if what this storm wants to try to do. I'm not sure if a developing tropical depression can survive crossing the island, and I bet in most cases it will not. However, this is the Hurricane Season of 2005, so consider it likely.
The long range radar loop
out of San Juan, PR, should be interesting to watch tonight. About 10-11pm convection should start to pick up, as we head into the usual midnight - 4am maximum in thunderstorm activity over the tropics. This may be enough to trigger the extra low-level convergence needed to get this storm spinning up into a tropical depression.
I figured out how to plot the early model runs (well, at least the BAMM and GFDL), I will try to keep this image updated.