MIAMI (AP) — A hurricane warning was issued Tuesday for a portion of southern Mexico as Tropical Storm Erick gained strength in the Pacific Ocean, forecasters said.

Tropical Storm Erick is forecast to intensify into a hurricane as it approaches the Mexican coastline this week.

Erick was a tropical storm in the North Pacific Ocean Tuesday morning Mexico Central Time, the National Hurricane Center said in its latest advisory. The tropical storm had sustained wind speeds of 45 miles per hour.