Hurricane Polo formed off Mexico's southwestern coast late Wednesday, threatening to spark floods and mudslides days after another storm wreaked havoc in popular resorts further north.

Polo was cruising parallel to the coast but was expected to bring tropical storm conditions over some Pacific states, according to the US National Hurricane Center.

Its maximum sustained winds reached 120 kilometers (75 miles) per hour, while Mexican forecasters warned that it would produce heavy rains in the states of Jalisco, Colima, Michoacan and Guerrero.

The new hurricane, which was 290 kilometers (180 miles) south of the port of Manzanillo, came almost exactly one year after twin tropical storms battered Mexico on both coasts, killing 157 people, the majority in Guerrero.

Authorities planned to evacuate scores of people in Guerrero's Playa Azul while 153 shelters were opened in Michoacan.

In its current track, Polo would just miss the Baja California peninsula, whose Los Cabos resorts were devastated by Hurricane Odile on Monday.

Odile thrashed the Mexican coast as a powerful category three hurricane on the five-level Saffir-Simpson scale, flooding hotels, flattening homes and sparking acts of looting, though no deaths were reported.

The government airlifted 5,000 tourists who were marooned in towns deprived of electricity and running water, while residents desperately sought aid and basic goods in supermarkets.

A tourism ministry spokesman said it would take another 48 hours to move all the 25,000 tourists who were still stranded after their hotels were wrecked by the hurricane.

The interior ministry said trucks were working to clear roads covered by landslides and that a bridge had collapsed.

The local airports suffered considerable damage, with operations limited to humanitarian flights and airlifts.

Telephone services were also severely disrupted due to a failure in an underwater cable.

After churning over the narrow Gulf of California as a tropical storm on Wednesday, Odile dissipated over the state of Sonora and crossed the US border.

The US storm center said the remnants of Odile were dumping heavy rain over the southwestern states of Arizona and New Mexico that could unleash life-threatening flash floods and mudslides.

The city of Phoenix, Arizona, opened an emergency operations center and offered sandbags to residents to protect homes from flooding. People in New Mexico also sandbagged their properties.