Tropical Storm Alberto weakens off Carolina coast

Pinpoint Doppler Radar at 3 p.m. Saturday (WCIV)

COLUMBIA, S.C. (AP) -- The first storm of the 2012 Atlantic hurricane season has weakened slightly off South Carolina's coast.

The National Hurricane Center said as of 11 a.m. Eastern on Sunday, Tropical Storm Alberto was about 90 miles (145 km) south of Charleston. It has maximum sustained winds of 45 mph (72 kph).

It's currently moving west-southwest, but forecasters expect it to turn northeast sometime Monday. It's not expected to make landfall in the Carolinas.

A tropical storm watch is in effect for the South Carolina coast from the Savannah River to the South Santee River.