TD 27: Future Gamma Developing in Caribbean

Tropical Depression 27 has developed just west of St. Lucia Sunday night. The future Tropical Storm Gamma is moving west through the Caribbean, a track that based on model forecasting looks to hold going forward. The future 'Gamma' is in a low-and-mid-level steering flow which is forcing the system to move to the west.

Gamma is forecast by the National Hurricane Center to NOT reach hurricane status in the next five days. The GFDL wants to wind Gamma up into a Category FOUR hurricane with winds to 140 mph in four days (see below). The GFDL has played Rita, Wilma, and Katrina perfectly but has also tanked on a couple of other systems (Ophelia coming to mind) so it is one option that bears watching.

The one thing that I think will prevent Gamma from going psycho in the Caribbean is wind shear in the upper levels of the atmosphere. There is substantial wind shead throughout most of the Caribbean and while it has subsided SOME, further lessening of the winds aloft is needed for Gamma to develop into the monster that the GFDL is looking at.

This system will not impact the US and will likely make landfall in Central America late this week. The potential for a hurricane does exist but at this point I'm not confident in that -- the wind shear is very potent and that is the factor that needs to be watched. If it continues to subside over the next 24 hours then my thinking will have to be revisisted. However, if the wind shear maintains itself or even strengthens, then Gamma may not be able to survive the trip across the Caribbean.