MIAMI (AP) — Heavy rain was pouring across much of Florida early Thursday as the first tropical storm of the Atlantic hurricane season headed toward the state's western coast and a new tropical storm warning was issued for a swath of the U.S. East Coast.

Tropical storm warnings were in effect for a large section of Florida's west coast from Boca Grande to Indian Pass and for the East Coast from Flagler Beach, Fla., all the way to Cape Charles Light in Virginia.

Tropical Storm Andrea's maximum sustained winds increased to near 60 mph (95 kph) and the storm was expected to make landfall in Florida's Big Bend area Thursday afternoon before moving across southeastern Georgia and the Carolinas. It was not expected to strengthen into a hurricane.

"The rain covers a good portion of the Florida peninsula even though the center is a couple of hundred miles off shore," said Eric Blake, a hurricane specialist at the U.S. National Hurricane Center in Miami.

Even before its center hit Florida, the storm disrupted graduation ceremonies at Clearwater's Countryside High School, where the Class of 2013 was supposed to graduate Thursday morning at Brighthouse Field, the spring training home of the Philadelphia Phillies. Principal Gerald Schlereth decided to move the ceremony to the high school's gymnasium. But the gym wouldn't accommodate the nearly 500 graduates, friends, families and school officials. So it was decided that the seniors would graduate in two sessions.

"You have to have a Plan B when weather is involved," said Ocy Ertzberger, head bookkeeper at the school of 2,400 students. "Students with last names A through L will graduate at 9:30 and students with last names M through Z will graduate at 11:30 a.m."

The split sessions would likely mean double-duty for the valedictorian, salutatorian and other graduation speakers.

Meanwhile, south Georgia residents were bracing for heavy rains that could lead to flooding.

Forecasters at the National Weather Service said heavy rains and flooding would be the main threats in Georgia, but isolated tornadoes also were possible.

"It looks like it's picking up speed and that's a good thing because it won't sit and rain us so long," said Jan Chamberlain, whose family runs the Blue Heron Inn Bed & Breakfast near the Sapelo Island Ferry station on Georgia's coast Thursday morning.

In Florida, storm surge was expected to be the biggest threat as the storm comes onshore, Blake said. The Hurricane Center expects a storm surge of 2 to 4 feet "near and to the south" of where the center makes landfall.

He added that flash flooding was a concern, with 3 to 6 inches of rain expected. Isolated areas in Florida and southeastern Georgia could get 8 inches of rain.

Already, the National Weather Service in Tampa confirmed two tornados touched down early Thursday — one in Myakka City and the other in Sun City Center. Meteorologist Rodney Wynn said there were reports of downed tree limbs and power lines and minor damage to the porch on at least one home. There were no reports of injuries.

Wynn said there have also been reports of minor flooding in the area, including along Tampa's Bayshore Drive.

Tornado warnings and watches could be issued throughout the day.

The storm was expected to hug the coastline, bringing rain as far as the southern New England area through the weekend.

As of about 8 a.m. EDT Thursday, the storm was centered about 160 miles (255 kilometers) west of Tampa and was moving north-northeast near 14 mph (22 kph).

In Florida, Gulf Islands National Seashore closed its campgrounds and the road that runs through the popular beach-front park Wednesday. The national seashore abuts Pensacola Beach and the park road frequently floods during heavy rains. On Pensacola Beach, condominium associations asked people to remove furniture on high balconies because of the expected high winds and beach lifeguards warned tourists of possible high surf.

In Alabama, authorities said that 13 people had to be rescued from rough surf kicked up by the storm Wednesday at beaches in two coastal towns. Most of those rescued did not require medical treatment.

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