Let me say this right off of the bat....Ernesto has been a tricky system to forecast for, and I have a lower degree of confidence about the forecast than I normally would in this type of situation. The upper air pattern next week over the U.S. is a rather complex one, and that in turn is making the eventual track of Ernesto even trickier than normal to figure out.
The shear that had been affecting Ernesto has essentially ended, and in response to that, Ernesto has rather rapidly organized into the first hurricane of this Atlantic hurricane season (remember the parachute reference below?). The outflow looks good in all directions around the hurricane, and I expect strengthening to continue today...maybe even become a Category 2 hurricane by tonight.
Due to the center reforming under the deep convection several times yesterday and last night, the system has stepped northward while the overall motion has continued to the WNW. Due to those northerly "steps," Ernesto will now make a close brush with Haiti and will cross Cuba in some form or fashion. A big key to the intensity forecast for Ernesto will be how long it stays over Cuba. If the system only spends about 12 hours or so over Cuba, then I still like the chances of Ernesto becoming a major hurricane over the Gulf. However, if it remains over Cuba for an extended period of time, or it crosses in an area where there are 5-6 thousand foot tall mountains, then it could be harder for Ernesto to get its act back together quickly enough to become a major hurricane. We shall see....
Almost every computer model has shifted its eventual U.S. landfall point eastward now (see below). Most models point to a Florida landfall, and based on the upper air data I am seeing, I am going to adjust my thinking as well. At this point in time with the data available to me, I think a Florida landfall is looking more and more likely. However, this track forecast depends on a weakness in the high pressure northeast of the system, and those are tough to get a handle on sometimes. So, obviously the forecast will have to continue to be adjusted with time.
Stay tuned...I will post a bit more later in the morning....
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