Fortunately, it appears that Ernesto’s circulation has been largely disrupted by the storm’s passage over Cuba. This may spare Florida a hurricane, although it’s too early to tell. From the 5 pm NHC discussion:

THE SYSTEM BECAME QUITE DISORGANIZED… WITH MOST OF THE DEEP CONVECTION LEFT BEHIND NEAR THE EASTERN TIP OF CUBA. SOME OF THIS DISORGANIZATION MAY BE DUE TO THE INFLUENCE OF A SMALL UPPER LOW JUST TO THE NORTH-NORTHWEST OF ERNESTO. RECENTLY…HOWEVER…SOME NEW CELLS OF DEEP CONVECTION ARE NOW DEVELOPING NEAR THE ESTIMATED CENTER. WE EXPECT SOME RE-STRENGTHENING TO OCCUR AFTER ERNESTO MOVES OVER THE ATLANTIC WATERS TO THE NORTH OF CUBA. HOWEVER SINCE THE INNER CORE HAS BEEN DISRUPTED BY THE CYCLONE’S PASSAGE OVER LAND…IT IS NOT ANTICIPATED THAT THIS STRENGTHENING WILL BE RAPID. IN FACT…THE SHIPS-BASED RAPID INTENSIFICATION INDEX SHOWS A LESS THAN 20 PERCENT CHANCE FOR RAPID STRENGTHENING. THE OFFICIAL FORECAST GOES WITH A BLEND OF THE SHIPS…GFDL…AND FSU SUPERENSEMBLE GUIDANCE AND KEEPS THE SYSTEM JUST BELOW HURRICANE STRENGTH BEFORE THE FORECAST LANDFALL IN SOUTHERN FLORIDA.

Dr. Jeff Masters says:

My best guess is for a very wet tropical storm with maximum winds of 60 mph hitting the Everglades.

The NHC’s wind speed probability table still shows a 45% chance of hurricane strength in 36 hours. A hurricane watch and tropical storm warning is in effect for the Florida Atlantic coast south of Vero Beach, the Florida Gulf coast south of Chokoloskee, and the Florida Keys. In addition, a tropical storm watch is in effect on the Gulf coast from Chokoloskee to Englewood, and a hurricane watch is in effect on the Atlantic coast from Vero Beach to New Smyrna Beach. Florida residents should continue monitoring this storm closely.