Tropical storm Ana barreled toward the US southeastern coast Saturday, threatening flooding, high winds and life-threatening tides in the region, forecasters warned.

Ana, which formed before the official June 1 start of the hurricane season, was expected to make landfall early Sunday.

The National Hurricane Center issued a tropical storm warning for South Santee River in South Carolina to Cape Lookout in North Carolina -- a 277-mile (446-kilometer) stretch of Atlantic coastline.

The forecasters also said communities in Virginia and eastern North Carolina should monitor Ana.

By late Saturday, Ana was 50 miles southeast of Myrtle Beach, South Carolina, and was moving north-northwest towards the coast at a speed of five miles per hour.

The storm could wreak havoc on coastal communities, with up to four inches (10 centimeters) of rain and winds up to 60 miles per hour expected.

"The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters," the Miami-based forecasters said.

"The water could reach one to two feet above ground at times of high tide in coastal areas from Cape Hatteras, North Carolina southward through South Carolina."

The NHC also warned of menacing rip tides off the coast.

"Swells generated by Ana are affecting portions of the southeastern US coast. These swells will likely cause life-threatening surf and rip currents," it said.

The storm's conditions will likely weaken once the storm moves inland, according to the NHC.

The harsh conditions are expected to continue through Monday, possibly putting a damper on Mother's Day plans for those celebrating the popular holiday on Sunday.