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 expected to rapidly intensify into a hurricane this week, with some meteorologists anticipating it will reach major hurricane status before making landfall in Mexico on Thursday morning.

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.