Early surprise Ana muscled up to a tropical storm early Saturday as it plodded ever closer to the Carolinas, threatening to push dangerous surf and drenching rains against the Southeast coast weeks ahead of the official start of the Atlantic hurricane season, according to AP. Ana was centered at 5 a.m. EDT about 115 miles (190 kilometers) southeast of Myrtle Beach, South Carolina, and had top sustained winds of 60 mph (95 kph), said Senior Hurricane Specialist Stacy Stewart at the U.S. National Hurricane Center in Miami. The storm was moving north-northwest at 3 miles per hour on a forecast track expected to bring it near the coasts of South and North Carolina sometime Sunday morning. A forecast advisory said it also was about 105 miles south-southeast of Cape Fear, North Carolina. Stewart said dangerous surf and rip tides appear to be the biggest threat posed by the Atlantic season's first tropical storm though isolated flooding in some coastal areas is also a concern. Ana marked the earliest subtropical or tropical storm to form in the Atlantic since another storm named Ana emerged in 2003, the Hurricane Center said in an earlier tweet. The Atlantic season officially runs from June 1 to Nov. 30, a period experts consider the most likely for tropical activity in the ocean basin. Stewart said Ana emerged from a subtropical system, meaning it initially had characteristics of both a tropical storm â€" which draws energy from warm ocean waters â€" and a traditional storm system driven by temperature changes typical of cooler weather before the season start. The center said a tropical storm warning extends from south Santee River in South Carolina to Cape Lookout, North Carolina, with 1 to 3 inches of rain expected over a wide area and up to 5 inches in some isolated spots. He also said the storm could push water 1 to 2 feet above normal height levels, causing some localized flooding.