Otis’s peak winds leaped 90 mph in 12 hours Tuesday, the fastest intensification observed in the northeast Pacific since satellite-monitoring of hurricanes began in 1966, according to Phil Klotzbach, a hurricane researcher at Colorado State University. Tuesday morning, Otis was a tropical storm with top winds of 70 mph. By the time it made landfall shortly after midnight Wednesday local time, it was a Category 5 hurricane with 165 mph winds.
“This is an extremely serious situation for the Acapulco metropolitan area with the core of the destructive hurricane likely to come near or over that large city early on Wednesday,” the Hurricane Center wrote.
When it barrels ashore, the Hurricane Center warned it will produce “catastrophic damage” near its center, both from a “life-threatening” storm surge or sudden rise in sea level and devastating winds that could produce tornado-like damage.
During Category 5 winds, “a high percentage of framed homes will be destroyed, with total roof failure and wall collapse,” the Hurricane Center writes. “Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.”
The storm’s torrential rain is forecast to produce widespread totals of 8 to 16 inches, and localized amounts up to 20 inches through Friday. “This rainfall will produce flash and urban flooding, along with mudslides in areas of higher terrain,” the Hurricane Center wrote.
Scientists say extreme intensification of storms like Otis, fueled by abnormally warm ocean waters, is made much more probable because of human-caused climate change. Just this week, a study described increases in rapid intensification in Atlantic storms in the past several decades.
“The increased likelihood for hurricanes to transition from weak storms into major hurricanes in 24 hours or less was particularly striking,” Andra Garner, the study’s author, told The Washington Post.
Hurricane warnings stretch from Punta Maldonado northward to Zihuantanejo along the southern portion of Mexico’s west coast in the state of Guerrero; this warning zone includes Acapulco. The area has no experience with a hurricane as strong as Otis and has only been affected by substantially weaker storms since records have been kept.
“There are no hurricanes on record even close to this intensity for this part of Mexico,” the Hurricane Center wrote.
This is uncharted territory for #Acapulco with a Major Hurricane approaching. The last hurricane to approach from the south like #Otis was an unnamed Category 1 in 1951. No Major Hurricane has threatened this region in recorded history. Pauline ’97 the winds were blowing offshore pic.twitter.com/EK6q3QveHw
— Bill Karins 💧 (@BillKarins) October 24, 2023
Storms that intensify as rapidly as Otis are most difficult to prepare for as they leave little time for governments to warn residents and for emergency management to mobilize resources.
Mexican President Andrés Manuel López Obrador said on social media that disaster planning was underway, and encouraged people to move to shelters and to stay away from rivers, streams and ravines.
The state of Guerrero is working closely with the armed forces and the Acapulco government to “redouble efforts” to strengthen “surveillance, prevention and assistance to the population,” state governor Evelyn Salgado Pineda said in a post on Facebook.
Abelina López Rodríguez, mayor of Acapulco, said on Facebook that 25 temporary shelters have opened across the city for those whose homes are at risk.
Meteorologists often describe poorly predicted, rapidly intensifying storms like Otis as a worst-case scenario, especially when immediately leading up to landfall.
On X, formerly Twitter, meteorologists said they were shocked by Otis’s sudden strengthening, which computer models failed to predict.
“Just a catastrophic failure of modeling with this one. Leads to a poor forecast outcome in the worst possible way for the Acapulco area,” posted Matt Lanza, who operates the Eyewall, a website for hurricane commentary.
This is wild. Models didn’t have #Otis a hurricane 24 hours ago, now it’s expected to be a Category 5 near landfall tomorrow. That’s Mother Nature for you. https://t.co/UFrpio0e5Y
— Matt Devitt (@MattDevittWX) October 25, 2023
Although forecasts of hurricane strength have improved markedly in recent years, the prediction of rapid intensification remains a major challenge — especially for compact storms like Otis, which are more prone to sudden changes in their environment.
Otis has drawn comparison to Patricia in 2015, which also underwent extreme rapid intensification off Mexico’s west coast and became the most intense hurricane on record in the northeast Pacific. However, that storm weakened some before landfall.
Otis is set to become the fourth tropical storm or hurricane to strike Mexico’s west coast this month, following Lidia, Max and Norma.