Hurricane Irma is still way out in the Atlantic Ocean, but with the hurricane hunters making regular trips to Irma's eye to collect weather data, many of the weather models are starting to come together. Right now, it is likely that this storm will make landfall as a major hurricane (category 3 or higher) somewhere in the northeastern Caribbean, including South Florida.
I still do not have to much confidence on exactly where it will make landfall. However, it's impacts on Florida or other parts of the Southeast will be dependent on whether this storm makes landfall in one of the larger Caribbean Islands, stays over water, or goes through the Bahamas.
I am generalizing these three scenarios for ease of understanding. There are outliers still forecasting a near miss for the U.S. east coast, but the Northeastern Caribbean will almost certainly not escape the devastating effects of Irma.
If Irma takes a more southern track, it could make landfall in Puerto Rico, The Dominican Republic, or Cuba. These islands are very mountainous and could weaken the hurricane significantly, perhaps below major hurricane status before nearing Florida.
The worst case scenario is if Irma takes the middle track. In this case, it could possibly strengthen to Category 5 since it will mostly would remain over open water. However, some models still keep this at a Category 4 or strong Cat. 3 on this path.
Either way, there would be large devastating impacts for South Florida. A landfall in the southern Bahamas and Turks and Caicos would be possible with this scenario as well.
The northern track of this storm would take Irma over the Bahamas. Since these Islands are isolated and not very mountainous, Irma would not weaken much and likely maintain major hurricane status. The east coast of Florida would still see a lot of rain and perhaps even a close call with the eye of Irma, but the storm surge would not be as a bad, since it would only be a glancing blow. This situation would still be bad for Florida.
However, Irma would turn further up the east coast and could make landfall somewhere between Georgia and North Carolina. We are still too far out to give anymore details on what the impacts would be to these areas in this scenario. There is still the slight possibility of it curving out to sea, but it is really unlikely.
The time frame if we were to have a U.S. landfall would be late Saturday night (if South Florida) to late Monday night (if North Carolina). At this point in time, a South Florida landfall looks like the most likely situation, but things can still change this far out.
I will post the link to my Facebook live video below: