Floridians, tourists and thousands of visitors for the Republican National Convention are preparing for Tropical Storm Isaac, which is expected to strengthen to a hurricane by the time it reaches the Florida Keys.

While there were few signs of the approaching storm in Tampa, convention officials called off most events until the storm passes. They planned to convene briefly as planned on Monday, then postpone most of the schedule until Tuesday afternoon.

First day of RNC effectively canceled as Isaac looms

Streets were already shut down around the Tampa Bay Times Forum, where former Massachusetts Gov. Mitt Romney is expected to accept his party's presidential nomination Thursday night. Law enforcement milled about downtown, and some protests already were under way. One group protesting homelessness and the housing crisis "took over" a foreclosed home by cleaning the yard and planned to help a homeless couple move in.

Florida Gov. Rick Scott declared a state of emergency and canceled his plans to attend convention events on Sunday and Monday.

President Obama called Scott Sunday and pledged to provide any resources the state needed to deal with the storm, including help with the Republican National Convention.

A hurricane warning had been issued for the Florida Keys, and officials warned tourists to leave. Forecast models show Isaac likely won't hit Tampa head-on, but it could lash the city with rain and strong winds just as the convention ramps up. A tropical storm warning was extended up Florida's Gulf coast north of Tampa Bay.

"I told some of my Democratic friends, `We are the storm, baby, we are the thunder,'" said Steve Linder, whose business is planning all events for the Michigan delegation. Linder added, smiling, "and it ain't gonna stop until November."

Dianne Joachim of New Richmond, Wis., was in town for her first convention and vowed not to let Isaac ruin it.

"I just figure God's got this," she said as she arrived at her downtown hotel.

Scott said during a media briefing that delegates were being told how to stay safe during a storm, and officials were ready for storm surge, bridge closures and other problems that could arise during the convention. He also said he was in close communication with local, state and federal agencies, as well as convention officials.

"We are a hospitality state. We know how to take care of people and we want to ensure their safety," the governor said.

Information from the Associated Press was used in this story.