The storm was 595 miles (960 kilometers) southwest of the southern tip of the Baja California peninsula of Mexico, and was moving west at 20 mph (31 kph). It had maximum sustained winds of 100 mph (155 kph), according to the Miami-based National Hurricane Center.
Kristy became a tropical storm Monday off of Mexico's southern Pacific coast before strengthening Tuesday into a Category 1 hurricane. It was expected to rapidly intensify into a Category 3 storm Wednesday, forecasters said.
The storm was expected to continue moving over open waters without threatening land. There were no coastal watches or warnings in effect.
"This one is moving due westward at a quick forward speed well out to sea, so no concerns for land," said Brad Reinhart, a senior hurricane specialist at the center.
In the Atlantic Ocean, Oscar disintegrated into tropical remnants Tuesday after making landfall in Cuba as a Category 1 hurricane on Sunday. The island is recovering from flooding and power outages.