MEXICO CITY -- The first hurricane of the eastern Pacific season brushed past the coastal shoulder of southwestern Mexico, keeping just off shore while sweeping the coast with heavy rains and winds that raised the threat of flash floods and mudslides.

Hurricane Enrique was expected to move past the Cabo Corrientes bulge during the night, and begin losing strength Monday as it headed toward a possible run at the southern end of Mexico's Baja California peninsula as a tropical storm by midweek.

Enrique's maximum sustained winds were holding around 90 mph (150 km/h) late Sunday, the U.S. National Hurricane Center said.

The center said "little change in strength" was expected during Sunday night. `'Enrique is then expected to begin weakening on Monday and continue to weaken through early this week" as it keeps farther from the coast, it said.

Late Sunday, the storm's core was about 60 miles (95 kilometres) south-southwest of Cabo Corrientes -- the bulge on the coast south of Puerto Vallarta -- and moving north at 8 mph (13 km/h).

The hurricane center said Enrique could drop 6 to 12 inches (15 to 30 centimetres) of rain, with isolated maximums of 18 inches (45 centimetres), over Colima state and coastal sections of the states of Jalisco, Michoacan and northern Guerrero.

A hurricane warning was in effect from Playa Perula to Cabo Corrientes. A tropical storm warning was posted from Punta San Telmo to Playa Perula and from Cabo Corrientes to Punta Mita.

Mexico's Defense Department has said troops were being deployed to aid civilians in advance of the storm.