EASTERN NC -

The series of forecast models that make up Tropical Storm Isaac's official track have become more focused and indicate a path directly toward the southern tip of Florida.

The National Hurricane Center's official forecast track has Isaac over Key West, Fla., Monday morning and then continuing toward the Florida panhandle on Tuesday.

StormTrack 12 Meteorologist Skip Waters has been keeping a vigilant eye on a high-pressure system in the Atlantic that has been pushing Isaac's projected path westward with each release of new information. He is closely monitoring that system because if the recently picked-up storm activity in the Atlantic weakens that system, there's a chance Isaac could turn northward sooner than expected and have an East Coast landfall.

"I am not arguing with that official track, especially since this afternoon the computer forecast models have come into even better agreement on that path," Waters said. "I am concerned that the combination of Tropical Storm Isaac and Tropical Storm Joyce ... could weaken the high pressure ridge that is steering Isaac to the west. If that happens there is a very real chance that Isaac could turn more to the north once moving off Cuba. I'm not ready to say it is going to happen, but I feel comfortable saying that it could happen."

Either way, Waters said the storm will still have an effect on Eastern North Carolina weather next week.

"Whether there is a shift to the east or a shift to the west, all of the forecast models take the remnants of Isaac northward across Georgia and South Carolina and through central and eastern NC on Wednesday, bringing heavy rainfall to parts of our state which are already pretty wet," Waters said. "So I am alerting you to the threat for flooding rainfall and possibly enough wind to take down some of these trees that are standing in wet soil."

That would be next Tuesday night and Wednesday, Waters said.

The official forecasted landfall had moved westward Thursday because the storm broke up and then re-formed overnight, and during that action the storm shifted its track.

"The single center that emerged last night was a little further to the south than the original center," Waters said. "That has triggered the models to project a path that is a little to the south and west of what we were looking at yesterday."

Isaac was charted about 165 miles south of Puerto Rico Thursday afternoon, and had sustained winds of 40 mph. It was tracking west at about 15 mph.

Tropical Storm Joyce formed Thursday over the open water of the Atlantic Ocean, but doesn't pose an immediate threat to land. Forecasters reported that Joyce is on a projected five-day track that would keep the storm out at sea east of the U.S. coast.