James P. Kossin

Feb 7, 2024 | pnas.org | Michael Wehner |James P. Kossin |Parsa Vahidi |Omid G Sani

For a number of years, I have argued that we are now, thanks to the effects of human-caused warming, experiencing a new class of monster storms—”category 6” hurricanes. That is to say, we are witnessing hurricanes that—by any logical extension of the existing Saffir-Simpson scale—deserve to be placed in a whole separate, more destructive category from the traditionally defined (category 5) “strongest” storms. Up until now, that was really just a matter of opinion (1).

Feb 5, 2024 | pnas.org | Michael Wehner |James P. Kossin |Michael Mann |Parsa Vahidi

SignificanceGlobal warming leads to more intense tropical cyclones (TCs). Three separate lines of evidence from both observations and models suggest that the open endedness of the 5th category of the Saffir–Simpson hurricane wind scale becomes increasingly problematic for conveying wind risk in a warming world.