Tropical Storm Olaf strengthened into a hurricane in the Pacific on Thursday as it churned toward the beach resorts of Los Cabos on Mexico's Baja California peninsula, meteorologists said.
Olaf was packing maximum winds of 145 kilometers per hour (90 mph), making it a Category 1 hurricane, the lowest on the five-level Saffir-Simpson scale, the U.S. National Hurricane Center said.
At 7 p.m. local time (0000 GMT Friday) the storm was about 72 km (45 miles) southeast of the seaside resort of Cabo San Lucas and moving northwest at 16 kph (10 mph), it reported.
Mexico's National Meteorological Service warned that Olaf was likely to make landfall as a Category 2 storm.
A hurricane warning was in effect for a stretch of Baja California coastline from Los Barriles to Cabo San Lazaro.
The storm was expected to move near or over the southern part of the peninsula on Thursday night and into Friday, forecasters said.
"Preparations to protect life and property should be rushed to completion," the hurricane center said.
A dangerous storm surge was expected to be accompanied by large, damaging waves near the coast, it added, warning that heavy rainfall may trigger "significant and life-threatening flash flooding and mudslides."
Authorities set up storm shelters, and schoolchildren in the state of Baja California Sur were told to stay home on Friday.
Ports were closed for smaller boats, and 24 flights were canceled at the Los Cabos and La Paz airports.
The hurricane comes at a time when Mexico is still recovering from a 7.1 magnitude earthquake and major flooding in parts of the country.