The National Hurricane Center is forecasting Tropical Storm Ernesto to move to the northwest and clip the Yucatan Peninsula before moving towards the Gulf Coast. Let's take a look at Ernesto now.
A center of circulation is definitely evident on satellite imagery, with the strongest convection shown in red. At this time, banding of showers and storms is evident on all sides of the storm, and this banding appears to center in the western part of the storm, where the circulation appears the strongest. According to this imagery, the southeastern and general eastern sides of the storm system appear strongest, with the most intense convection.
A loop of water vapor imagery indicates that there is a wide expanse of dry air ahead of Ernesto, and moving west as Ernesto is. This does concern me for possible development, as the western part of the system may never get too organized it the dry air keeps itself in the path of Ernesto. That lack of development in the western flank may hurt overall development for the system.
Lower level winds also pose a challenge for development, with at least 20 knots of lower level winds present. While not tremendous, this does still introduce another obstacle that will need to be dealt with by Ernesto in order to ensure proper development. Additionally, winds to the west of Ernesto are also strong, and this will only continue to hurt chances for significant development over the next 5 days in the Caribbean.
Shear tendencies near Ernesto are fairly strong, with at least 50 knots of shearing on the northeast side of the storm system. While that is to the northeast, there is another 30 knots or so of shearing to the west of Ernesto, with tendencies on the rise in the area. This, combined with significant lower level winds, will likely pose an interesting situation for Ernesto's development chances.
Short range model guidance suggests that Ernesto is to skirt the Yucatan Peninsula before moving into the Gulf of Mexico. When the system does move into the Gulf of Mexico, it can be expected that rapid strengthening may occur for the system. If such rapid strengthening is to happen, I could see a moderate strength hurricane setting its sights on the Gulf Coast.