Polo, a tropical storm in the Pacific Ocean, is expected to become a major hurricane this week

Tropical Weather - (NOAA via AP)

Tropical Storm Polo will rapidly intensify in the Pacific Ocean and become a major hurricane later this week, forecasters said Monday.

Polo could bring heavy rain, rough surf and tropical-storm-force wind to parts of Mexico late Tuesday into early Wednesday, according to an advisory from the Miami-based National Hurricane Center.