Hurricane Sandy is bearing down on the Atlantic coast, with forecasts projecting it will build enough strength to cause power outages and up to 6 inches of rain in the District by Monday.

The storm continued to plow forward Saturday about 335 miles off the coast of Charleston, S.C., sustaining about 75 mile-per -hour winds. Gusts of wind up to 50 miles an hour are expected to hit a large portion of the mid-Atlantic coast by Sunday night, according to a 2 p.m. advisory by the National Hurricane Center.

Conditions will likely be worst Monday into Tuesday. Some nearby colleges, including the College of William & Mary in Virginia, have already cancelled Monday classes.

University spokeswoman Candace Smith did not immediately return a request for comment when asked if GW would cancel classes.

Meteorologists and public officials have warned D.C. residents to prepare for the worst, which would mean a direct hit that would cause coastal flooding and strong rain and wind that lasts through Tuesday.

Mayor Vincent Gray declared a state of emergency in the District Friday afternoon.