More than 3,500 officers from 59 law enforcement agencies from around the state are scheduled to come to Tampa to patrol the streets as the convention opens Monday. About half would come from outside Hillsborough County and the city of Tampa.
About 1,700 National Guard troops were already expected to help with patrols. Hillsborough County Sheriff David Gee said the number could increase if other law enforcement agencies don't end up sending officers.
The storm is forecast to start affecting South Florida on Monday and could reach the Tampa area by Tuesday.
"We're in a situation right now where we don't know what's going to happen," Gee said. "My primary concern right now is that we will lose resources."
Gee said some agencies, especially in South Florida, might decide not to send officers to Tampa if the storm threatens their areas. "As things change, they might have to prioritize," he said.
Gee's agency is in charge of the county where the convention will take place. The Hillsborough Sheriff's Office is providing the bulk of the staffing for the event because it is the largest agency in the area and also oversees the county jail. The Tampa Police is the other main agency handling security outside of the convention hall. The Secret Service is in charge of everything inside the convention hall.
The sheriff joined Tampa Police Chief Jane Castor and representatives from the FBI and Secret Service at a media event Thursday. As they spoke to reporters, a large TV screen tuned to a cable news channel showed colorful radar images of Isaac swirling in the Caribbean.
Convention officials said they were working closely with state and federal authorities on monitoring the storm.
"We continue to move forward with our planning and look forward to a successful convention," convention CEO William Harris said in a statement.
Florida Gov. Rick Scott said RNC officials were on a call Thursday with state, local and federal authorities and there were no plans to cancel the convention.
Scott pointed out that the storm is still trending westward, and he hoped it would not have a major impact on Florida.
"It's a forecast and all the forecasts are prone to error, but fortunately it has gone a little bit west," Scott said. "Hopefully it will dissipate by the time it gets over Cuba."
Scott also said Florida "is more prepared than any state in the country for hurricanes."
"The National Guard will be ready for any contingency," he said. "So if that happened then the logical backup would be the National Guard."
Jeff Masters, director of meteorology for Weather Underground, said the storm's current forecast indicates Tampa is unlikely to take a direct hit from a potential hurricane. When the storm passes the Bay area, it's likely to have an east-west motion, meaning it could sideswipe Tampa, causing rain and flooding, but not directly strike the city.
Chief Castor said she wasn't worried about redeployment of officers; when she initially asked other agencies to help, she told them they should only send people that they could spare.
She said the security team factored in the possibility of another event, such as a storm, happening during the RNC.
"We'll adjust our plans," she said. "We're used to that in law enforcement."
Steven Ibison, the special agent in charge of the Tampa division of the FBI, said he wasn't concerned about the number of officers on the ground.
"The FBI isn't involved in weathercasting," he said. "But we have plans in place. We always do here in Tampa."
Castor and Gee stressed it was too early for any agency to dramatically change plans. Castor said that no one would really know where Isaac was headed until late this weekend.
"The only predictable element about a tropical storm or hurricane is its unpredictability," she said.
Associated Press Writers Gary Fineout in Tallahassee and Christine Armario in Miami contributed to this report.