MIAMI -- Hurricane Sandra has strengthened to a powerful Category 3 storm off Mexico's Pacific coast, but there is no current threat to land.

The U.S. National Hurricane Center says it's the strongest hurricane in the eastern Pacific for this late in the year.

The hurricane's maximum sustained winds increased Wednesday afternoon to near 115 mph (185 kph).

Sandra is centred about 555 miles (895 kilometres) southwest of Manzanillo, Mexico, and is moving northwest at 8 mph (13 kph).

It's expected to turn to the north-northwest Thursday, and to weaken sometime Thursday or Thursday night.