Tropical Storm Isaac has become better organized and it continued today on a track that potentially could put it somewhere off the South Florida coast by early Monday.
The threat to Caribbean islands was clear and more immediate as Isaac closed in on the chain of Leeward Islands, according to a Miami Herald report. Warnings and watches also were posted for Puerto Rico to the Dominican Republic, which along with Haiti could see heavy rains, flooding and mudslides.
At 5 a.m. today, the National Hurricane Center said Isaac was moving west at 18 mph with maximum winds of 45 mph. Forecasters said conditions were favorable for continued strengthening.
Forecasters expect the storm to reach hurricane strength by Thursday as it approaches Puerto Rico and continue west until Saturday, when Isaac would be near or crossing Hispaniola.
From there, computer models predict that Isaac will begin turning more to the northwest, with the timing of that turn dictating whether it will make landfall in South Florida or brush it on either side — a direction determined by the strength of a high-pressure ridge to its north and a trough digging down from the southeastern United States.