The Category 3 storm will quickly weaken over the next 24 hours as it makes its way across the Sierra Madre range and becomes a rainmaker for northern Mexico and Texas on Wednesday. But before that happens, Willa will bring life-threatening storm surges, rain and wind to residents on Mexico's Pacific shore, according to the US National Hurricane Center.Willa, once a Category 5 hurricane, had weakened before landfall, but still had maximum sustained winds of 120 mph (195 kilometers per hour)."Life-threatening storm surge, wind, and rainfall (are) spreading onshore," the US hurricane center said earlier.After landfall, Willa is expected to weaken quickly as it runs into the mountains, and it will be a rainmaker by the time it crosses the US-Mexico border Wednesday. Forming Saturday, Willa went from a tropical storm to a Category 5 hurricane in two days in what the hurricane center called"explosive" strengthening.In one 24-hour period, its winds spiked by 80 mph. Forecasters are concerned about storm surge and rainfall."Near the coast, the surge will be accompanied by large and destructive waves.," the hurricane center said. "Rainfall will cause life-threatening flash flooding and landslides."Rainfall totals could reach 18 inches in portions of the Mexican states of Durango, Jalisco, Nayarit and Sinaloa.Willa has been a danger for forecasters as well. An aircraft with the Air Force Reserve's Hurricane Hunters was forced to turn around Monday over concerns for its onboard equipment after a lightning bolt from one of Willa's outer rain bands blasted it, according to the National Hurricane Center.In a tweet Monday, Mexican President Enrique Peña Nieto said he has asked the National System of Civil Protection to take all steps necessary to protect those in the hurricane's path as well as those affected by Tropical Storm Vicente, a weaker system tracking south of Willa that's also primed to make landfall Tuesday. Vicente likely will be a tropical depression by the time it comes ashore, the hurricane center said.Airlines have started moving out of Willa's path. Southwest Airlines has canceled all flights at the international airport in Puerto Vallarta, a resort city in Jalisco state. American Airlines has canceled its flights in Mazatlán, about 275 miles to the north.Willa's landfall will come three years to the day after the strongest hurricane to hit the Pacific coast, Patricia, a Category 5 storm, made landfall in Jalisco.The back-to-back systems of Willa and Vicente have helped make the 2018 hurricane season in the northeast Pacific one for the record books.The season is now the most active hurricane season on record using a measurement called accumulated cyclone energy, which combines the number of storms and their intensity through their lifetimes to give an overall measurement of tropical activity in a given region.There have been 10 major hurricanes this year, including Willa, tying 1992 as the most major hurricanes in the northeast Pacific in one year.Increasing numbers of major hurricanes, along with a greater propensity of storms to undergo "rapid intensification" are expected consequences of warmer ocean waters resulting from climate change. The ocean waters off Mexico's western coast are running 1 to 2 degrees Fahrenheit above average for late October.
CNN's Michael Guy contributed to this report.