The dead finback whale that has been drifting through ­Boston Harbor washed ashore at Georges Island over the weekend before floating back out to sea, officials said.

On Monday morning, the 50-foot whale “appears to have washed out of channel out to sea,” said S.J. Port, spokeswoman for the Department of Conservation and Recreation. She said high tides and westward winds helped moved the animal’s remains out of the harbor area. They currently cannot be located.