Tropical Storm Emily tracking toward Florida, possibly Southeast coast

The Lowcountry's first real worry of the hurricane season is spinning in the Atlantic Ocean.

Rain from the outer bands of Tropical Storm Emily began falling Tuesday in Puerto Rico as the system moved on a track that would take it to the island of Hispaniola within 48 hours and possibly to Florida by the end of the week, possibly putting it on path to move north along the Southeast coast.

Here in the Lowcountry, today's forecast calls for a high of 94 degrees with temperatures tomorrow set to soar to 99 degrees with heat index values as high as 110 degrees.

It is the fifth tropical storm to form in the Atlantic Basin so far this year, and it signals that the bedeviling Cape Verde period is here.

With the "Bermuda High" bobbing back and forth onshore and offshore of the United States, it could be a matter of timing on whether Cape Verde cyclones get pushed out to sea, into the Caribbean or up the East Coast, said Mark Malsick, S.C. Climate Office severe weather liaison.

The high-pressure system's wheel-like wind circulation tends to act like a "gate keeper" steering storms. Last year the system stayed onshore, and none of the 19 named storms that formed -- including 12 hurricanes, five of them major -- made landfall on the East Coast. Forecasters expect nearly that many storms this year.

Cape Verde storms are roiling West Africa disturbances that move into the Atlantic, spin into cyclones and curl toward the Southeast. The period tends to run from August through September. A wave typically rolls off the coast every three or four days -- an average of 60 to 70 per season, according to National Hurricane Center specialists. On average, one in 10 become tropical cyclones.

"The waves rolling off Africa have been looking more robust the last few days. The Bermuda High ... will either shove any storm west into the Caribbean or Gulf of Mexico, or allow the storm to re-curve (toward the East Coast)," Malsick said in an email. "This is a forecast problem of timing that we should see for the month of August at least."

With Emily stalling south of Puerto Rico, most government offices closed and people cleared water and other emergency supplies from store shelves. The showers and wind gusts were sporadic and there were no reports of major flooding or injuries.

The storm was expected to bring up to 6 inches (15 centimeters) of rain in Puerto Rico, enough to trigger floods and mudslides to an island that is already saturated from months of heavy rain.

The storm was moving on a northwestern track that forecasters said would reach Hispaniola, the island shared by Haiti and the Dominican Republic, by Wednesday. Both countries, but especially Haiti, are prone to devastating floods.

Civil defense officials and the military in the Dominican Republic have already begun moving people out of high-risk zones ahead of the storm.

Forecasters at the National Hurricane Center said the storm was about 270 miles (435 kilometers) southeast of San Juan, Puerto Rico at 11 a.m. EDT (0900 GMT). It had been meandering, but the forecasters said they expected it to resume its westward path at about 12 mph (19 kph) later in the day.

A wind gust of 49 mph (80 kmh) was reported on St. Thomas in the U.S. Virgin Islands, the U.S. National Hurricane Center said.

A tropical storm warning was in effect for Puerto Rico, Vieques, Culebra, the Dominican Republic and Haiti. A tropical storm watch was in effect for the U.S. Virgin Islands.

Reach Bo Petersen at 937-5744 or follow him on Twitter at www.twitter.com/bopete.