Subtropical Storm Beryl swirls toward southeast coast MIAMI (Reuters) - Subtropical Storm Beryl moved slowly toward the U.S. southeastern coast on Saturday, threatening heavy rains and dangerous surf for Memorial Day weekend beachgoers in northern Florida, Georgia and South Carolina. Beryl was centered about 220 miles east-southeast of Charleston, South Carolina, carrying maximum sustained winds of 45 mph. It was moving southwest, with tropical storm-force winds extending about 115 miles from the storm's center. The storm was not expected to develop into a hurricane, said Jack Beven, a senior hurricane specialist at the U.S. National Hurricane Center in Miami. Forecasts indicate the center of the storm will make landfall either late Sunday or early Monday, Beven said. Weather models show Beryl will eventually turn back toward the Atlantic, posing no threat to oil and gas production facilities in the U.S. Gulf of Mexico. Tropical storm warnings were in effect for Sunday from the Volusia/Brevard County line in northern Florida to Edisto Beach, South Carolina. Dangerous surf conditions, unusually high tides and flooding were possible along the coasts of northeastern Florida, Georgia and South Carolina over the holiday weekend, the hurricane center said. Total rainfall could reach between 3 and 6 inches in some areas, it said. Beryl is being called a subtropical storm, meaning it has a broader wind field than tropical storms, and shower and thunderstorm activity farther removed from the storm's center. A change in the storm's structure could see Beryl reclassified as a tropical storm but would not alter its potential impact, Beven said. Beryl formed off the South Carolina coast late on Friday and is the second named storm of the Atlantic hurricane season, which has had an early start. The season officially runs from June 1 to November 30. Reporting by Kevin Gray; Editing by Peter Cooney