POSTED: Wednesday, August 22, 2012 - 8:30am
UPDATED: Wednesday, August 22, 2012 - 8:44am
(CNN) — Tropical Storm Isaac churned away in the Atlantic Ocean early Wednesday, forecast to strengthen into a hurricane and posing a potential threat to the GOP convention in Florida next week.
It's too early to tell what effects the storm will have on the U.S. mainland. But several computer models bring the storm into the Gulf of Mexico, while others move it farther east over Florida.
With roughly 50,000 people headed to Tampa for the Republican National Convention starting Monday, there is heightened interest in the future path of the storm.
At 8 a.m. ET, Isaac was about 210 miles east of Guadeloupe in the Leeward Islands with maximum sustained winds of 45 mph -- a slight increase from earlier in the morning -- and was moving west at 19 mph, the National Hurricane Center in Miami said.
Tropical storm warnings cover much of the Leeward Islands as well as Puerto Rico and the Virgin Islands.
A hurricane watch is in effect for Puerto Rico, the U.S. Virgin Islands and the Dominican Republic, which means hurricane conditions are possible within 48 hours.
"Strengthening is forecast during the next 48 hours ... and Isaac could become a hurricane by Thursday," the hurricane center said.
Puerto Rico Gov. Luis Fortuno said the U.S. commonwealth has as many as 433 shelters ready to be activated by local mayors as the storm approaches. He said he expects rain from the system to reach Puerto Rico Wednesday afternoon.
Forecasters caution that the forecast track is uncertain and the storm could be anywhere from the Bahamas to the north and the Cayman Islands to the south on Sunday.
CNN's Jason Hanna, Brad Lendon, Dave Hennen and Sean Morris contributed to this report.
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