As noted on the Main Page, Invest 99L was upgraded to Tropical Depression FIVE this afternoon.

TD5 is going to be another tricky one to forecast. On the one hand, FIVE has a healthy surface low pressure circulation riding atop warm waters. On the other hand, the tropical cyclone is already pushing up into a region of moderate to high southwesterly shear, limiting the convection to the southern semicircle. Additionally, subsident, dry air is still in some abundance in the western Atlantic.

Future track probably won't be as challenging to forecast as its intensity. The first official forecast overall leans towards the GFS solution, gradually strengthening TD5 into Hurricane Ernesto by the time it reaches the western Caribbean. On this forecast track, the Lesser Antilles will likely have a wet and blustery coming weekend.