The tropical storm may also cause damage in Tampa, Fla., where the GOP convention will take place. Weather Channel meteorologist Jim Cantore reports.
By Weather.com and wire reports
Tropical Storm Isaac headed toward the Dominican Republic and Haiti on Friday, continuing its march across the Caribbean after unleashing heavy rain on parts of Puerto Rico and prompting Florida officials to urge residents to prepare now.
The storm had top sustained winds of 45 miles per hour, but forecasters said it could become a hurricane by Monday, when it could pass near Florida's Gulf Coast just as the Republican National Convention is scheduled to start in Tampa.
It's been years since a significant storm impacted the Florida coastline, and officials are concerned that residents have become complacent and will not be ready.
"I think it's a challenge of getting people to understand their risk and make sure they’ve got a plan," said Craig Fugate, administrator of the Federal Emergency Management Agency.
With more than 19 million people living across the Sunshine State, Fugate wants every Florida resident to have enough supplies to last 72 hours and to know when to evacuate.
"I think the most dangerous thing is when people keep waiting to see what the next forecast is even if they’re in an evacuation zone. They say, 'Oh, it’s just a Category 1 storm or a minimum hurricane.' We’ve seen significant impacts from tropical storm force winds and rain," Fugate added.
Follow Isaac's path with our storm tracker
In the Florida Keys, where there are few routes available for evacuation -- U.S. 1, Key West International Airport, and the Florida Keys Marathon Airport -- Mayor Craig Cates said his biggest concern was the storm's timing. With the size and strength of Isaac late Thursday evening, Cates said he would need at least 36 hours to begin evacuations of tourists and residents.
"If it (Isaac) comes straight on to Key West, we’re worried about the damage that could happen in Key West. If it goes further up the Keys, it could damage power lines and we could get affected," Cates said. "Even if it hits further up the state, we have got to be prepared with our generators and our supplies. Being on an island, we understand that."
Forecasters with The Weather Channel think the evacuation decisions could come quickly. It is anticipated that watches will be issued for South Florida and the Keys by Friday night. In the event of an evacuation, Cates told The Weather Channel that tourists would leave first, followed by special needs citizens. Cates stated that residents wouldn't need to leave just yet, given the strength of the storm at this point.
Live updates and analysis from weather.com
The Florida State Emergency Operations Center was activated to a Level 2 on Thursday. The EOC's website defines Level 2 as a limited agency activation. All primary, or lead, Emergency Support Functions are notified.
On average, 87 million people visit Florida's beaches, theme parks and other attractions each year, Gov. Rick Scott said, but in the coming week more will be arriving for the National Republican Convention in Tampa.
Despite Tropical Storm Isaac's threatening winds and rains ahead of the GOP convention in Florida, Mitt Romney and running mate Paul Ryan are taking aim at President Obama and his handling of the economy. NBC's Peter Alexander reports.
Scott said state officials are working with convention organizers, who will ultimately make the call on a delay or cancellation of the event.
"These officials have been working together on the convention for the past 18 months. The possibility of a hurricane has been part of that planning process," Scott said. "All that’s required for those plans to be activated would be for there to be a hurricane and hopefully that will not happen."
State officials announced Thursday afternoon that they will wait to make decisions about moving supplies until after Isaac passes Cuba. FEMA has already placed food and generators in Jacksonville.
Eric Blake, a forecaster with U.S. National Hurricane Center in Miami, told The Associated Press later Thursday that "we think it could become a hurricane on Monday. It would be somewhere over the Gulf of Mexico."
The latest five-day forecast showed the storm's path shifting to the west, possibly making landfall near the Alabama-Mississippi border, Blake said. But he said it was "too early to know" the exact course and stressed that Florida's Gulf Coast, including Tampa, the site of next week's Republican National Convention, was still in the forecast cone.
Andrea De Silva / Reuters
Rosemary Beharry surveys damage caused by a mudslide in the kitchen of her home in Carenage, Trinidad, in the wake of Isaac on Thursday.
The U.S. National Hurricane Center warned it was "important not to focus on the exact track because of forecast uncertainties and the fact that Isaac has a large area of tropical storm force winds."
It said Isaac was centered about 115 miles south-southeast of the Dominican Republic's capital, Santo Domingo, as of early Friday morning.
With nearly 400,000 people still living in evacuation tents, a hurricane or even a tropical storm could lead to deaths and more damage to the already fragile country. NBC's Mark Potter reports.
Isaac was expected to dump between 8 and 12 inches of rain over parts of Hispaniola, with total accumulations up to 20 inches in some areas, the NHC said, posing a significant threat to Haiti, which is highly prone to flooding and mudslides because of its near-total deforestation.
"These rains could cause life-threatening flash floods and mud slides," the center said in its Friday advisory.
Haiti, the poorest country in the Americas, still has about 350,000 people living in tents or makeshift shelters more than 2-1/2 years after a devastating earthquake that took more than a quarter of a million lives.
Red Cross workers toured crowded tent camps of Haitians left homeless by the 2010 quake to warn about Isaac. Text messages were sent out to tens of thousands of people urging them to stay away from rivers and evacuate tent camps in case the storm hits.
Authorities in the Dominican Republic began evacuating people living on the banks of rivers, streams and areas vulnerable to landslides in preparation for the approach of Isaac, whose effects were beginning to be felt with showers in the south of the country.
Weather.com, Reuters and The Asscoiated Press contributed to this report.
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