With the latest advisory, NHC has maintained Ernesto's wind speed at 60 mph. The official forecast calls for Ernesto to enter the Gulf of Mexico early next week, where it could become a very powerful hurricane. Tropical storm watches and warnings are now active for Jamaica and parts of Hispanola. Hurricane watches are now up for Jamaica and the Cayman Islands. Ernesto may reach hurricane strength some time in the next 12-36 hours.
Ernesto's limited strength thus far has been due to moderate wind shear displacing the convection from the center of circulation. While the center of circulation used to be on the very edge of the convection, it is now within the convection but displaced towards the west. This wind shear should lessen today and tomorrow, and allow for strengthening to continue. The current convective pattern is very healthy and Ernesto seems to mean business.
The models are in clear consensus on a track over Cuba by Tuesday at the latest. By early to mid next week, Ernesto could be roaming the Gulf of Mexico as a hurricane. However, there has been a recent shift to the north and east.
Most of my trusted models are also calling for Ernesto to strengthen into a hurricane. The GFDL, SHIPS, LGEM are all calling for steady intensification of Ernesto into a hurricane, but not as strong as before.