With the June start of the hurricane season in North America, this month’s “This is not Cool” video surveys projections by expert scientists on the outlook for tropical cyclones.
MIT hurricane expert Kerry Emanuel calls the 2015 hurricane season in the North Pacific “exceptional,” and atmospheric scientist Kevin Trenberth of the National Center for Atmospheric Research points out that 2015 was a record year for major storms, those rated Category 3 and above in strength.
“When you put that together with [2013’s Typhoon] Haiyan,” one of the most intense storms ever observed, Emanuel continues, “it begins to beg the questions ‘Why? Why now?'”
Weather Underground’s Bob Henson places current conditions into context, with a huge, but fading, El Niño event fading away, and possibly leading into La Niña conditions, more conducive to Atlantic hurricanes.
“NOAA is giving us a 75 percent chance that we’ll be in La Niña by the end of the year,” Henson says. “The odds of Florida being hit by a hurricane are about twice as much during a La Niña as during an El Niño.”
Trenberth adds that with so much action occurring in the Pacific during the El Niño, corresponding clear skies over the Atlantic and Indian Oceans allow those waters to warm up, stocking the fuel that can drive extreme storms.
Emanuel notes that in a warming atmosphere, “the thermodynamic limit for hurricane wind speed must go up. So you expect to see more storms at the very high end.”
According to Penn State University climatologist Michael Mann, “We expect the strongest storms to become even stronger, … and that’s what we’re seeing play out.”
This trend may be ominous, according to Emanuel, as it is the more unusual but more powerful strong storms that have been responsible for the greatest part of all damages.
“More than half the damage that’s been done in the United States dating back to the middle of the 19th century has been done, essentially, by just eight events,” he says.