The anticipated intensity of Hurricane Milton has led many experts to question the adequacy of the current storm categorization system.
With Hurricane Helene having recently impacted Florida’s Big Bend, Hurricane Milton is now on a similar trajectory. The US National Hurricane Center (NHC) has issued critical warnings as Milton has reached the maximum level on the Saffir-Simpson Hurricane Wind Scale.
The category five designation indicates winds at ‘157 mph or higher (252 km/h or higher)’ and predicts ‘catastrophic damage’.
This includes: “A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. 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.”
By yesterday evening, Hurricane Milton’s winds reached 180 mph, surpassing category five limits. Although it has since weakened to a category four, there is concern it could intensify back beyond category five.
This situation is sparking debate about whether the Saffir-Simpson Hurricane Wind Scale is sufficient for modern-day hurricanes.
Jim Kossin, a retired federal scientist and science advisor at the First Street Foundation, told USA Today that the existing system leaves category five open to ‘infinity’, making it increasingly inadequate as climate change fuels unprecedented hurricane intensities.
Earlier this year, Kossin collaborated with climate scientist Michael Wehner from Lawrence Berkeley National Laboratory in a paper proposing a ‘hypothetical category six’ with a minimum threshold of 192 mph.
Analysing storms since 1980, they determined that ‘a number of recent storms have already achieved this hypothetical category six intensity, and based on multiple independent lines of evidence examining the highest simulated and potential peak wind speeds, more such storms are projected as the climate continues to warm’.
While they do not advocate for the immediate revision of the scale to include a category six, they hope their study will inspire ‘discussions about how to better communicate risk in a warming world’.
Additionally, the current scale focuses mainly on wind, overlooking the severe risks posed by storm surges and flooding from rain, which can be even deadlier.
Professor Michael E. Mann shared on Twitter: “A compelling argument has been made that a hurricane with sustained wind speeds of 192mph or greater should be considered ‘category 6’.” He added, “There is some speculation that #Milton might have actually breached the 192 mph ‘cat 6’ cutoff. Stay tuned…”
Despite these discussions, meteorologist Mike Rawlins from Fox Weather considers a category six ‘unnecessary’. He told the Post he’s not ‘aware’ of any new scale being developed ‘at this time’.