Hurricane season in Atlantic to be ‘extraordinary’

To draw attention to the way that global warming is making the highest intensity storms more likely, a recent study, external explored the possibility of creating a new category six level.

This “would alert the public that the strongest tropical cyclones that we are now experiencing are unprecedented and the reason for that [is] the warming of the surface oceans because of climate change,” explains study lead author Michael Wehner, senior scientist at Berkeley Earth.

Hurricane categories only take into account wind speeds. But these storms pose other major hazards, such as rainfall and coastal flooding, which are generally worsening with climate change, NOAA warned.

Warmer air can hold more moisture, increasing the intensity of rainfall.

Meanwhile, storm surges – the short-term increases to sea level from hurricanes – are now happening on top of a higher base. That is because sea levels are now higher, principally due to melting glaciers and warmer seas.

“Sea-level rise increases the total flood depth, making today’s hurricanes more damaging than prior year’s storms,” says Andrew Dessler, a professor of atmospheric science at Texas A&M University.

Given the active forecast, researchers stress the need for the public to be aware of the hazards these storms can pose – in particular “rapid intensification events”, where hurricane wind speeds increase very quickly, and so can be especially dangerous.

“We are already seeing overall increases to the fastest rates at which Atlantic hurricanes intensify – which means that we are likely already seeing an increased risk of hazards for our coastal communities,” explains Andra Garner, an assistant professor at Rowan University in the US.

“It can still be difficult to forecast rapid intensification of storms, which in turn escalates the challenges that arise when trying to protect our coastal communities.”