We're hitting the limits of hurricane preparedness

The strongest storms, in fact, might only come about through rapid intensification. As Brian McNoldy, a senior research associate at the University of Miami, has noted, all four recorded Category 5 storms to make landfall in the continental United States had been tropical storms just 72 hours earlier. In the past few years, several prominent hurricanes have seemed to undergo this rapid intensification. Hurricane Michael, which carved a devastating path through the Florida Panhandle as a Category 5 storm in 2018, had been a relatively weak hurricane only two days prior to landfall. Hurricane Harvey, which deluged Houston in 2017, also intensified up to the moment that it came ashore.

Kerry Emanuel, a meteorology professor at MIT who is one of the most prominent scholars of hurricanes and climate change, has warned that rapid intensification poses a significant risk to accurate hurricane forecasting. “There’s a lot more cases of rapid intensification [in a warmed climate], and that includes the accident of it rapidly intensifying just before it makes landfall,” Emanuel told me in 2017.

If rapid intensification becomes more common, as Emanuel fears, then officials will find it harder to make good judgments about hurricanes. Over the past few decades, meteorologists have gotten significantly better at predicting where a storm might go, but they still don’t always know how strong it will be when it gets there. That’s a problem, because decision makers need to know both track and intensity to make good calls: Knowing a storm will pass overhead in three days is meaningless if you don’t know whether it will be Category 1 or Category 5 when it arrives.