Because the eye will be west of Miami, that puts the entire Miami metro area and areas south of it that was devastated by Andrew in 1992 under very serious threat, because the east side of a hurricane is usually the most intense and dangerous in terms of high winds and rainfall.
When hurricane Fran approached NC, it unexpectedly stalled over the gulf stream for 24 hours as a category 3. Conventional wisdom said it would intensify to cat 4. Instead, it remained cat 3, but doubled in size.
These storms can be a bugger to predict sometimes.