TAMPA — It's a nightmare scenario: a hurricane swirling off Florida as delegates start to arrive here for the Republican National Convention.How strong would it have to be to change the convention schedule or force a cancellation? What if it's just a tropical storm? How about a major storm that makes landfall in another part of the state, redirecting personnel and resources? And who makes the final call on what to do?The odds of a hurricane hitting the Tampa Bay area between Aug. 27-30, when the convention takes place, are mercifully slim — less than 1 percent, according to the National Weather Service. But officials are preparing for the worst, just in case.This week, state leaders will game-plan a convention hurricane, one that could ruin months of planning and waste millions in spending — not to mention deal a harsh blow to Mitt Romney's presidential campaign, which will use the event to kick-start its stretch run. Those high stakes are the reason emergency officials picked the RNC as the subject of their annual disaster drill."If it's in the realm of possibility, it's something we need to at least plan for," said Bryan Koon, director of the Florida emergency management division.Officials from around Florida will be given this scenario: Hurricane Gispert (named for retired Hillsborough County emergency manager Larry Gispert) is about to make landfall on Tampa in the middle of the convention, with 50,000 visitors, 5,600 delegates and up to 15,000 journalists in the storm's path.What to do?"Decisions are going to have to be made during the event," said Daniel Noah of the National Weather Service office in Ruskin.Bob Buckhorn knows he'll be sitting squarely on the hot seat.While the decision about whether to continue the convention, postpone it or cancel entirely would be up to the Republican Party and convention organizers, the decision about evacuating people would be a local one.Buckhorn, a Democrat, says he'll be ready to "err on the side of safety."And if the storm never hits?"If I get criticized for evacuating people for a storm that veers off at the last minute, I'm fine with that," he said.• • •When it comes to weather, convention officials aren't talking much about specifics.Organizers are "working with our partners at the federal, state and local levels to address and plan for every potential contingency — including those related to weather — and to ensure the health and safety of convention delegates, guests and visitors," a spokesman said in a statement.State emergency officials aren't taking any chances. Beginning Monday in Tallahassee, they'll act out their response to the fictitious storm from pre-landfall to recovery.It's more than a tabletop exercise, Koon said. Once officials learn the details of the storm planners have cooked up, they will stage a nearly full-scale response. Officials everywhere from Tallahassee to Miami will coordinate via phone and Skype and do just about everything short of dispatching rescue trucks.That includes preparing a meal, like the ones that would be served at emergency shelters. Participating officials eat it for lunch.In other years, they have squared off with a made-up Category 5 Hurricane Ono. Other times, they have dealt with two storms hitting at once.The make-believe storms are often modeled after real ones. In 2009, officials dealt with a storm like the Great Miami Hurricane of 1926.This year's practice won't just be about preparing for the weather.Think of all the people who will have to evacuate: tens of thousands of visitors who have only seen hurricanes on television. Thousands of people who have never put plywood on their windows, never left their belongings and headed for higher ground, never wondered what they'd do with pets or whether they had enough bottled water.All those people, crammed into downtown Tampa, which happens to be in evacuation zones A and B — the first places people will have to flee if a big enough storm blows through."It would require unique security and transportation … a whole host of dynamic pieces," Koon said. "This (exercise) gives us the opportunity to consider those."• • •If you think about it, a storm on the scarier side would make the decision easier on convention planners, said Noah, the National Weather Service forecaster. In that case, they'd probably just cancel the whole thing.It's the marginal ones, the tropical storms or Category 1 hurricanes, that pose a trickier call.Even a storm that misses Tampa could pose a threat, with resources and law enforcement steered away from the convention and toward the area that's hit."There are so many variables," Noah said.Because of that, the National Weather Service's office in Ruskin will operate 24 hours a day during the convention week — that's a first, as far as Noah can remember.Forecasters will consult with RNC officials multiple times a day, he said. In addition to the five-day hurricane forecast the office normally puts out, officials will also develop forecasts behind the scenes for six and seven days out.They'll track storms based on the probability of a number of factors, a departure from the old "cone" method used in the path. Rather than just following the storm's path or speed, forecasters will determine the danger to the Tampa Bay area based on the likelihood of high winds, storm surge, flooding and rain.There is no such thing as a perfect forecast, Noah says, but they'll do the best they can, constantly updating officials on short-term and long-term dangers."We always have to be prepared," he said. "We don't need a direct hit to have an impact."Consider Elena.In 1985, that Category 3 hurricane stalled off Cedar Key in early September. It was 100 miles northwest of Tampa, but the area still got significant storm surge flooding that damaged thousands of homes in Pinellas County, Noah said.And there was Gladys. The October 1968 hurricane made landfall near Homosassa, and Clearwater Beach felt wind gusts of up to 90 mph.The oddly named Hurricane Easy in 1950, which skidded along the edge of Florida before making a loop between Tampa and Cedar Key, brought 120 mph winds to the area."This is why I have flood insurance, even though I live in Valrico at 55 feet above sea level," Noah said.The last time a major hurricane hit Tampa Bay was 1921.The likelihood of that happening again, during that week in August, Noah said, is slim.But remember Charley?The storm, which was headed for Pinellas County before turning abruptly and hammering Punta Gorda, arrived the second week in August 2004. Charley's 145 mph winds killed 15 people and caused about $15 billion in damage.That storm's last-minute turn is something officials must keep in mind, too. Even storms not pointed at the bay area pose a threat."However unlikely, it is possible," Koon said. "Even as we hope it's nice and sunny."• • •Nice and sunny? That's probably unlikely, too.Augusts in Florida are more likely to be hot and steamy, with thunderstorms just about every day.Even the most routine weather patterns will pose problems for the thousands of people packed into downtown, said Bay News 9 meteorologist Josh Linker.Oppressive heat during the day will give way to afternoon downpours, complete with lightning strikes and the potential for flooding throughout South Tampa.And there's this extra challenge: Along with firearms, explosives and knives, a list of items that are prohibited inside the convention includes most umbrellas.Times staff writer Richard Danielson contributed to this report. Kim Wilmath can be reached at [email protected] or 813-226-3337.