Polo strengthens to Category 4 in eastern Pacific, heavy rain forecast for Mexico

Hurricane Polo intensified into a Category 4 storm in the eastern Pacific late on Monday, with forecasters warning of heavy rainfall along southwestern Mexico even as the system was expected to stay offshore.

Maximum sustained winds reached 130 mph (215 kph), and the storm could strengthen further to Category 5 by Tuesday or Wednesday, the U.S. National Hurricane Center said. Category 4 storms carry winds of 130-156 mph (210-250 kph) on the Saffir-Simpson scale, while Category 5 hurricanes exceed 157 mph (250 kph).

At the time, Polo was moving east-southeast at 5 mph (7 kph). It was forecast to make a sharp turn toward the northwest and then west-northwest, a track that would keep it near the Mexican coast for several days without coming ashore.

A tropical storm watch was in effect for a stretch of coastline from south of Manzanillo in Colima state to Tecpan de Galeana in Guerrero state, indicating that tropical storm conditions were possible within two days. The hurricane was centered roughly 330 miles (530 kilometers) south-southeast of Manzanillo late on Monday.

Forecasters warned of heavy rain, with the potential for flooding and landslides, across Guerrero and Michoacán through Thursday. Lesser amounts of rain were possible in coastal parts of Oaxaca, Colima and Jalisco.