A child walks in a neighbourhood as tropical storm Rick approaches Cabo San Lucas, Mexico, on Tuesday. (Guillermo Arias/Associated Press)

Tropical storm Rick slammed Mexico's Pacific coast just north of Mazatlan on Wednesday after sparing Los Cabos on the Baja peninsula a direct blow.

The centre of the storm made landfall Wednesday morning with winds as high as 90 km/h. The wind kicked up massive waves that drew residents of Mazatlan to the city's seaside boulevard to watch.

Authorities had no immediate reports of significant damage, although it has been raining in the area since late Tuesday.

In nearby Sinaloa, authorities suspended classes for two days in cities along the state's southern coast and urged people to evacuate low-lying areas.

Gov. Jesus Aguilar asked residents in a radio message to pay close attention to civil protection advisories and said soldiers were ready to help with possible evacuations.

Over the weekend, Rick's winds were clocked at 290 km/h, but the storm spent its force far out at sea and weakened over cooler waters.

Rick's maximum sustained winds were down to 100 km/h Tuesday night, the U.S. National Hurricane Center said.

Hurricane Neki growing

Meanwhile, far out in the Pacific Ocean, Hurricane Neki was centred about 1,000 kilometres west-southwest of Honolulu.

A hurricane watch was issued for the Papahanaumokuakea National Monument, a marine conservation area northwest of Hawaii.

Forecasters predicted Neki would brush by tiny Johnston Island on Wednesday.

The uninhabited island, which is part of the isolated Johnston Atoll, is under the primary jurisdiction and control of the U.S. air force. The U.S. Fish and Wildlife Service has a national wildlife refuge there.