MEXICO CITY -- Lidia became an "extremely dangerous" Category 4 hurricane Tuesday with winds of 225 km/h (140 mph) as it took aim at Mexico's Pacific coast resort of Puerto Vallarta.

The U.S. National Hurricane Center said Tuesday that Lidia could continue to strengthen just hours before making landfall.

The hurricane was expected to make landfall near Cabo Corrientes and then move inland just to the south of Puerto Vallarta, which could cushion the blow on the resort.

Local authorities canceled classes in communities around the coast. The expected impact comes one day after Tropical Storm Max hit the southern Pacific coast, hundred of miles away, and then dissipated. Rains from Max washed out part of a coastal highway in the southern state of Guerrero.

Lidia was centered Tuesday about 175 kilometres (110 miles) southwest of Puerto Vallarta, and was moving east-north-east at about 26 km/h (16 mph).

The hurricane center warned of possible flash flooding and storm surge from the hurricane.