It continues to push toward the northern Leeward Islands, where tropical storm watches are now in effect as of the 8 p.m. update from the National Hurricane Center. Intensification is expected as Erin moves toward warmer ocean temperatures over the next several days.

The hatched areas on the National Hurricane Center's tropical outlook map indicate "areas where a tropical cyclone — which could be a tropical depression, tropical storm or hurricane — could develop," said National Hurricane Center Deputy Director Jamie Rhome.