Hurricane Polo intensified to Category 5 on Tuesday, September 22, off Mexico’s Pacific coast, becoming the strongest category on the Saffir-Simpson scale after an exceptionally rapid strengthening. The National Hurricane Center (NHC) and Mexico’s National Meteorological Service (SMN) were monitoring the storm as it moved offshore.

Polo strengthened from a Category 1 hurricane to Category 5 in less than 24 hours. By Tuesday, it had maximum sustained winds of around 260 kilometers per hour (160 mph), with stronger gusts.

The storm was located south of Zihuatanejo, Guerrero, and Manzanillo, Colima, while a tropical storm watch remained in effect along part of the southwestern Mexican coast.

Authorities warned of heavy rainfall, strong winds, high waves, flooding and landslides in parts of Guerrero, Michoacán, Colima, Oaxaca and Jalisco. The storm’s circulation was expected to produce dangerous conditions even as its center remained offshore.

Guerrero and Michoacán suspended classes on September 22 and 23 as a precaution. Mexico’s Federal Electricity Commission also deployed personnel, vehicles, generators and other emergency equipment to prepare for possible storm-related damage.