Jimena developed into a dangerous Category 4 storm off Mexico's Pacific coast Sunday, threatening to hit the Baja California peninsula as a major hurricane in coming days.
Jimena swirled far enough away from land Sunday to spare Mexico's southwestern coastline, only sprinkling the port of Manzanillo with light drizzle.
If it stays on its northwestern track, however, it could carry hurricane-force winds to the tip of resort-dotted Baja California by late Monday and slam into the peninsula by Wednesday morning, said Richard Pasch, a senior specialist with the National Hurricane Center in Miami, Florida.
Pasch noted that Jimena's path "is subject to some uncertainty" and that it is difficult to predict how strong the storm will be when it nears Baja, although he said it is likely to be dangerous.
"I think it's going to be a substantial hurricane by the time it approaches them," he said.
A public advisory issued by the hurricane center advised residents in western Mexico and the southern part of the Baja peninsula to keep tabs on Jimena.
Economists from around the world were scheduled to attend a conference sponsored by the Paris-based Organization of Economic Cooperation and Development on Tuesday and Wednesday on the peninsula. It was not clear if the conference will still take place; the organization's public relations office was closed Sunday.
Jimena had maximum sustained winds near 135 mph (215 kmh) Sunday and was moving northwest near 9 mph (15 kph.) It was centered about 285 miles (460 kms) south of Cabo Corrientes, Mexico.
Farther out in the Pacific, Tropical Storm Kevin had top winds of 50 mph (85 kph) and was centered about 960 miles (1,540 kms) southwest of the Baja peninsula's southern tip.