How we measure hurricanes is inadequate—and potentially deadly
With severe storms like Harvey and Irma becoming more common, it’s time to leave the Saffir-Simpson scale in the 20th Century
HURRICANE HARVEY is bearing down on Texas, putting approximately 4.6m lives at risk. Currently a Category 4 storm (out of 5), Harvey is far more dangerous than even that classification might suggest. Perhaps it would be a good time to address a gaping hole in the world’s natural disaster-mitigation armor: the Saffir-Simpson Hurricane Wind Scale.
A scientific relic
Created almost a half-century ago, the Saffir-Simpson scale is used measure the severity of a hurricane. More specifically, the National Hurricane Center (NHC) defines it as a “1 to 5 categorization based on the hurricane’s intensity at the indicated time”. Only that’s not exactly accurate, as it only considers wind speed. The NHC definition, and the Saffir-Simpson scale itself, is antiquated, oversimplified — and ultimately, dangerously misleading.
Not just blowing hot air
Strong winds can correlate with overall strength—but not always. Other meteorological phenomena such as heavy precipitation and storm surge also play a major role—and are often more deadly. Spin-off elements, if you will, like water spouts, tornados and counterintuitively, fires, can also cause major devastation.
Consider Hurricane Katrina, which hit the Gulf Coast of America in 2005. Yes, the wind speeds were truly impressive (max. sustained of 175mph). Yet what led to an estimated 1,500 deaths was largely flooding from extensive rain and storm surge, along with the unfortunate physical geography of New Orleans. (Of course, unpreparedness of those who decided to stay behind and the catastrophic incompetence of government didn’t help.)
Hurricane Sandy, which hit New York and New Jersey in 2012, is perhaps even more relevant. It made landfall as a weak Category 1 by Saffir-Simpson standards, with sustained winds around 80mph—barely a breeze. Yet it took hundreds of lives and caused an estimated $50 billion in damage, due in no small part to storm surge and, indirectly, over 190 fires.
When hurricanes are initially reported as a threat to land, meteorologists always, first and foremost, highlight a storm’s Saffir-Simpson “Category”. A “Hurricane Watch” or “Warning” forecasts the areas which might or will see hurricane-force winds. This results in wind speed being a primary consideration when residents decide whether to evacuate or ride it out. Living in a hurricane-prone area myself, I’ve been guilty of buying a bottle of rum and battening down the hatches too.
Meteorologists aren’t totally at fault; media outlets are also guilty of bluster. Absurd wind speeds obviously inspire more tweets than rainfall totals, but they shouldn’t be blown out of proportion. After a particularly bad 2005 Atlantic Hurricane season, a number of journalists suggested adding a Category 6; a misguided and pointless proposition that detracts attention from potentially more important storm elements. It’s a shame that scientists are wasting time considering the hype.
All the gear, no idea
Since the creation of the Saffir-Simpson scale in 1971, science and technology has progressed more than during any other era in human history. We’ve sent rovers to Mars, accepted (most of us) that climate change is anthropogenic. Meteorologists have ever-more-precise satellite and forecasting equipment at their disposal. Heck, I just paid for my coffee with a digital credit card that is linked, via wireless data on my mobile phone, to my skint bank account—using a thing called the internet.
Yet when it comes to what is one of the most important measurements in weather—one which millions of lives and hundreds of billions of dollars rely on each year—all we can muster is adding a category and making some minor tweaks?
A more accurate barometer
As with the dating game, journalists need to do a better job of making tropical storms sexier without sacrificing their complexity. But everything must be backed up by science. That’s why it’s up to meteorologists to figure out a more comprehensive alternative to Saffir-Simpson.
A better scale could focus on air pressure. Generally speaking, the lower the pressure, the more powerful and well-defined a storm is. An ideal scale, however, would probably aggregate all the major elements of a storm: wind, rain, and storm surge, while also taking into consideration the affected area’s physical geography. If rainmakers like Sandy and Harvey were taken more seriously, fewer lives would be lost.