Transcript for Isaac Rolls in to Florida; RNC Ready?
As we come on the air, tropical storm isaac threatening to deliver a body blow to the east coast. It now has 45-mile-per-hour winds, and is growing stronger. It is expected to reach hurricane strength this time tomorrow. And at this hour, this is the most likely projected path. By friday, isaac will hit the dominican republic, then cuba and then onto south florida, hitting there late sunday, early monday morning. In fact, just as the republican national convention is getting under way. And, take a look at its size. Isaac, already as big as texas. It has been seven years since the last big hurricane hit florida, raising new concern tonight about readiness on shore. And abc's matt gutman is there. Reporter: Tropical storm isaac churning more than is 1,000 miles away from the florida coast. But at this florida emergency operations center, the storm is all too close. We're making a lot of phone calls, working with a lot of agencies. Reporter: Already, there has been evacuations of 200 visitors at the u.S. Base at guantanamo bay. Emergency manager chiefs called to assist at the rnc, like kurt sommerhoff, are saying put to ride out the storm. What is your biggest concern overall? All year lock, it's been complacency. Reporter: Will ma did billions in damage. We don't want to get caught up in the numbers. Yes, a 5 is much stronger than a 1. But even a 1 can do damage. A hurricane is a hurricane is a hurricane. Prefair for all of them. Reporter: Eric has his team at florida international university bretted the wall of wind, which can similar late a monstrous cat 5 storm. So, when we talk a category 1, the concern is not really the power of the wind but debris flying off. It's a multi-pronged attack. The wind can do destruction. But it's what you put in the wind. Flying debris, anything coming into that structure can certainly damage it. Reporter: We lashed a camera to the roof of one of the huts. You see the rain pounding, before it is send airborne. And not much of a sense of urgency here, diane. A lot of the folks we spoke to tonight say they're going to wait and see what this storm brings. But emergency management officials said even a category 1 storm is essentially take the atlantic ocean and dump it right into the first floor of those condos. Diane? Matt, thank you. I want to bring in abc's weather editor sam champion. Talking about sunday night, monday morning. How sure can the weather center be about the trajectory of this storm? Reporter: Five days out, diane, this is the official path. But you notice we're not looking at one rain, right through the middle of that path. A red cone. And that gives them some wiggle room, even more at the very end of the foreman cast period. They know there's a lot that can happen. A lot that is pushing it, pulling it. A lot of land it can interact with. We are looking at many forecast models. Dozens of them. And we condense them maybe down to the five more reasonable, and that givens us the idea right now, of where this storm is going. But a lot of them seem to go through or near florida. So, what about the strength as we just heard, category 1, 2, what's the worst it can do? Reporter: Well, right now, we hold it at a 1, maybe bopping it around a little bit. But we are more concerned about how it hits. Heavy wind and rain. Flood from rain and strong winds. Isle re irene, one of the costliest and most damaging in u.S. History was just a tropical storm when it made landful in the new york city area. I had forgotten that. Okay, sam, thank you so much. And, now, we turn to an abc news exclusive.
This transcript has been automatically generated and may not be 100% accurate.