POLO HAS GROWN into one of the most powerful Pacific cyclones in decades and was expected to skirt Mexico’s south-western coast as a major hurricane.

The US National Hurricane Centre (NHC) in Miami called Polo an “extremely dangerous” storm and forecast the system would turn sharply to the north-west before moving west-northwest over the next several days.

Early on Wednesday, Polo was about 185 miles south of Zihuatanejo and 335 miles south-east of Manzanillo, moving north at 2mph with maximum sustained winds of 155mph, the centre reported.

That put it near the top of Category 4 strength, after earlier being a Category 5 storm.

“Fluctuations in intensity are expected, but Polo is expected to remain a very powerful major hurricane during the next few days,” the NHC said.

Meanwhile, Odalys has strengthened from a tropical storm to a Category 1 hurricane without threatening land.

Odalys was about 1,295 miles off the southern tip of Baja California moving east-northeast at 9mph with maximum sustained winds of 75mph, the hurricane centre said.

Mexican President Claudia Sheinbaum said experts indicated Polo was not likely to touch land.

Still, hurricane-force winds extend up to 40 miles from the storm’s centre and tropical storm-force winds up to 105 miles from the eye, the US centre said.

Hurricane Odalys in the Pacific Ocean (NOAA via AP) NOAA via AP NOAA via AP

Tropical storm conditions were expected along the Pacific coast in the states of Guerrero, Michoacan and Colima.

On Tuesday, Polo became the third Category 5 hurricane of the Pacific season, following Genevieve and Lowell earlier this year.

Category 5 is the highest level on the Saffir-Simpson scale, reflecting that a storm has maximum sustained winds exceeding 157mph.

The hurricane set residents along Mexico’s Pacific coast on edge once again after being walloped by a number of powerful cyclones in recent years.

Beaches emptied and dark clouds swirled above choppy seas, while Mexican authorities temporarily suspended classes on Tuesday in a number of areas.

Mexico’s navy shut down ports in the states of Guerrero and Michoacan and warned civilians and fishermen to take care.

US National Hurricane Centre data shows Polo’s winds reached speeds comparable to only a few hurricanes in the region in recent decades, primarily Hurricane Patricia, which had winds that reached 215mph in 2015.

“This is one of the strongest storms ever in the (Pacific) Basin,” said Kristen Corbosiero, professor at the University at Albany’s Department of Atmospheric and Environmental Sciences.

Heavy rain could produce flash flooding and mudslides.

The rapid intensification of the storm has stunned scientists and authorities alike, with the NHC writing in a report that it was “truly remarkable” how quickly Polo gained strength in 24 hours.

Philip Klotzbach, research scientist at the Department of Atmospheric Science at Colorado State University, attributed the intensification to the weather phenomenon known as El Niño, which has fuelled crippling droughts in Mexico and Central America and floods in other parts of the region.

In the Pacific, it has resulted in warmer waters and wind patterns that act as fodder for hurricanes, he said.

“There are all the ingredients that hurricanes need to get really strong, really fast,” Mr Klotzbach said.

No Atlantic hurricanes have formed yet this year, and this year has set a record for the longest start to a season without a hurricane. The effects of this year’s El Niño crush storms before they get going.