The Tampa Bay area took a collective deep breath Friday as forecast models showed Tropical Storm Isaac veering west into the Gulf of Mexico.
But experts said any track showing what Isaac might do after it emerges from Cuba and spills into the Florida Straits remains little more than an educated guess. Forecasters on Friday night issued a Tropical Storm watch for a large part of South Florida, but Tampa Bay was not included — at least not yet.
If the storm stays on its projected path, experts said, it will miss directly hitting Tampa, where more than 50,000 visitors are gathering for the GOP convention.
"If," said National Hurricane Center meteorologist Rick Danielson. "That's still a big if."
Some localities chose to err on the side of caution: Pasco officials declared a state of emergency, St. Petersburg opened its Emergency Operations Center and Madeira Beach stocked up on sandbags and filled extra fire stations.
Hillsborough, Pinellas, Hernando and Manatee counties will wait and see.
"We're expecting some minor rain," said Preston Cook, director of Hillsborough County Emergency Management. "We're postured for that."
Forecasters at the National Hurricane Center cautioned that even a glancing blow from the storm could result in a whole lot more. The storm is big, with tropical storm-like conditions extending more than 185 miles from its center. And it's liable to grow, Danielson said.
"The full range of impact is possible," he said. "Absolutely no one should discount the possibility that some sort of severe weather will occur."
Even if Isaac passes west of Tampa Bay, it could strafe the region with rags of vicious storm bands carrying heavy rain, high winds and tornadoes.
Isaac is an unusual storm. It's disorganized, it's sloppy and it's hard to predict.
The cone of uncertainty used in forecast models provides the wiggle room forecasters believe the storm might take. Anywhere inside that area is still fair game, Danielson said.
That includes Tampa.
The Republican National Convention has contingency plans for bad weather but is not discussing them or saying when it would have to decide whether to put them into effect.
"We continue to talk with Gov. (Rick) Scott's office and local authorities and the National Weather Service and monitor the situation," convention spokesman James Davis said Friday. "We're looking forward and planning on having a great event next week."
Pinellas County spokesman Tom Iovino said Friday that given Isaac's current trajectory, he is "cautiously optimistic" that the area will be spared from severe flooding.
Isaac was traveling about 15 miles an hour Friday night as it approached Haiti. If it stays at that speed, it would be out of Tampa Bay's hair far faster than Tropical Storm Debby, which trudged along much more slowly earlier this summer.
"If you've got a big, sloppy system like Debby that's not moving for two days you could get 15 inches of rain," he said. "With a fast-moving storm you're bound to see far less rain. Unless something strange were to happen."
Fed by dry air, Isaac has shown multiple centers and has been unable to develop — unusual for a tropical storm.
Late Friday, Isaac was just off the coast of Hispaniola. It looked likely to skirt the island, missing its tallest mountain peaks, before moving toward Cuba. Isaac was expected to travel up the spine of Cuba —a journey that could change the nature of the storm.
Land travel usually slows storms down. If Isaac slows too much before re-entering the gulf, it could crawl up Florida's shoreline slowly, growing bigger and stronger over warm water, increasing the danger of storm surge and flooding rains.
Forecasters urged vigilance.
But fishing guides and boat captains at O'Neill's Marina in St. Petersburg shrugged the storm off Friday afternoon.
None had tied down their boats. Few believe they'll have to.
Mike Gore, 41, said more than the storm itself, fishermen feared how its presence might scare away customers.
"Mother Nature is going to do what Mother Nature is going to do," said Capt. Lee Blick, 51. "Sure, watch what the forecast is, but take it with a grain of salt."
Times staff writer Richard Danielson contributed to this report. Marissa Lang can be reached at firstname.lastname@example.org or (727) 893-8804 or on Twitter @Marissa_Jae.