Hurricane Simon strengthened into a Category 2 storm Friday as authorities prepared for possible landfall in Jalisco or Colima — potentially bringing catastrophic winds, dangerous storm surge and flooding to Mexico on the heels of Hurricane Polo last week.

Forecasters expected the Pacific storm to become a major hurricane Friday evening and reach Category 4 strength Saturday, with sustained winds of 230 km/h (145 mph), according to a Friday morning advisory from the U.S. National Hurricane Center (NHC).

At 3 p.m. Mexico City time, the storm had maximum sustained winds of 165 km/h (105 mph) and was about 315 kilometers south of Manzanillo, Colima, moving northwest at 4 km/h (2 mph).

The eye of the storm is forecast to turn north and pass very near or over Mexico’s west-central coast late Saturday or Sunday. Tropical storm conditions are expected to carry through Saturday morning, followed by hurricane conditions Saturday evening or Sunday.

Simon could become the second hurricane to make landfall in Mexico this Pacific season, following Polo, which struck Baja California Sur on Sept. 28 and Sonora on Sept. 29.

Simon’s precise track remains uncertain. The NHC said the storm could weaken rapidly or dissipate if its center moves inland. If its core stays offshore, it could continue north as a hurricane.

A hurricane warning issued by Mexico’s National Water Commission (Conagua) remains in effect from Punta San Telmo, Michoacán, to Punta Mita, Nayarit — points roughly 475 kilometers (295 miles) apart by road. A hurricane watch extends north to San Blas, Nayarit, while a tropical storm watch extends south to Lázaro Cárdenas, Michoacán.

Dangerous storm surge could strike the coast and nearby inland areas, accompanied by large, destructive waves. Rainfall could trigger life-threatening flooding and mudslides, particularly on steep terrain.

Simon could bring 20 to 38 centimeters (8 to 15 inches) of rain across parts of southwestern Mexico through Sunday, with isolated totals of 64 centimeters (25 inches) in Michoacán, Colima, Jalisco and Nayarit, according to the hurricane center.

Laura Velázquez, Mexico’s national civil protection coordinator, said authorities Friday would establish command centers in Puerto Vallarta, Cihuatlán and Manzanillo.

Authorities began evacuations in El Rebalse, a community in Jalisco that is vulnerable to flooding from the Marabasco River. Seventy residents left on their own and 10 were moved to a shelter, Reuters reported.

Schools in 22 Jalisco municipalities suspended classes Friday and Monday.

Meanwhile, Hurricane Isaias, a Category 3 storm, was churning through the Gulf of Mexico, with landfall in the U.S. expected Friday evening, according to the hurricane center. No landfall in Mexico is forecast.

With reports from El Sol de México, Reuters and La Silla Rota