The storm strengthened a little bit while moving right along the north coast of Puerto Rico , and after an increase in convection near the center , Olga made landfall near Punta Cana , Dominican Republic at 1800 UTC on December 11 . The storm strengthened slightly while paralleling the north coast of Puerto Rico , and after an increase in convection near the center , Olga made landfall near Punta Cana , Dominican Republic at 1800 UTC on December 11 .