Mexico braced Tuesday for the impact of Hurricane Willa as the Category 3 storm barreled toward its Pacific Coast with what forecasters warned would be potentially deadly force.
Willa was a maximum Category 5 hurricane on Monday, but lost strength as it moved toward landfall -- expected on Tuesday afternoon or evening, the US National Hurricane Center said in its 1500 GMT update.
Nevertheless, the NHC warned, "Willa is expected to be a dangerous hurricane when it reaches the coast of Mexico."
It was on course to slam into Mexico between the states of Sinaloa and Nayarit, somewhere around the resort town of Mazatlan.
The NHC said aircraft data showed the core of the storm was currently sweeping over the Marias islands, where Mexico has a federal prison.
The interior ministry did not immediately respond to questions on whether it had evacuated the 1,000 inmates housed there or what other emergency measures were in place for the penal colony.
In Mazatlan, a tranquil beach town with turquoise waters, the hotels that line the coast were largely empty as workers nailed plywood over the windows.
Residents were stocking up on food and water, but there were no signs of shortages so far.
"We bought supplies for the whole family -- bottled water, unperishable food, things we can eat quickly," said Roberto Carlos, 45, as a light rain set in and wind started to sway the town's palm trees.
Willa has maximum sustained winds of 205 kilometers (125 miles) per hour, the NHC said.
It is expected to dump 15 to 30 centimeters (six to 12 inches) of rain on parts of Sinaloa, Nayarit and Jalisco states, with some areas getting up to 45 centimeters.
"This rainfall will cause life-threatening flash flooding and landslides," the NHC warned.
The Hurricane Center said that large storm swells off the coast are also "likely to cause life-threatening surf and rip current conditions."
Willa was located about 205 kilometers south-southwest of Mazatlan, churning north-northeast at nine kilometers per hour.
State of alert
The states of Sinaloa, Nayarit and Jalisco declared a state of alert and cancelled school state-wide.
In the resort town of Puerto Vallarta, Jalisco Governor Aristoteles Sandoval on Monday ordered the evacuation of hotels and coastal areas, warning the storm could have "very destructive consequences."
Shelters were opened on higher ground to accommodate evacuees.
In Michoacan state, also on the Pacific coast, heavy rain caused a freight train to derail Monday in the town of La Goleta, injuring at least two workers for the Kansas City Southern rail line, authorities said.
Adding to the weather chaos, the remnants of Tropical Storm Vicente were moving over Michoacan on Tuesday, bringing more heavy rainfall.
Mexico's Pacific coast has already been hit by deadly storms and rains this hurricane season.
In September, at least 15 people were killed when flash floods hit the states of Sinaloa and Michoacan. Last week, 11 more people died in Oaxaca, including seven children.