Easterlies are when the wind blows from the east, all movements will normally take off and land into wind so therefore when easterlies blow the aircraft fly towards the east. Conversely the opposite applies on westerlies.
While 27L has been partially blocked the runway has been used for departures to the west but at reduced lenght. Any heavies requiring full lenght for departures have had to wait for gaps in arriving traffic on 27R.