A study by scientists at the National Center for Atmospheric Research looked at how 20 Atlantic hurricanes would be different if they took place at the end of this century, if the average projection for global warming came true. The study found they would generate an average of 24% more rain.
Daniel Brown, senior hurricane specialist and warning coordination meteorologist, at the National Hurricane Center, said that while the future may well bring rainier hurricanes, it would be premature to conclude from a few recent storms that such a future has arrived.
"We've seen slow-moving storms in the past that have dumped copious amounts of rain, and we'll see that in the future," he said. "It takes more than a few storms to see a long-term trend."
Whether or not climate change is responsible for the heavier rains, scientists say there's evidence hurricanes have slowed their forward motion and will continue to do so. That would mean other parts of the country could experience the misery of Texas under Hurricane Harvey, which stalled over the state, pounding it with rain for four days.
A study in the journal Nature found that tropical cyclones have decreased their forward speed by 10% since 1949, and many scientists expect this trend to continue.
"Studies have suggested hurricanes could be slower," said Brown, of the National Hurricane Center. "That is a recipe for very heavy rain-producing hurricanes."
The familiar system for classifying hurricanes, where Category 1 represents a relatively weak storm and Category 5 represents a monster, relies solely on wind speed. Experts say this emphasis on wind carries over to the public, where there continues to be a lack of appreciation for the risks posed by rain.
"People are very wind-centric," said Bill Johnson, emergency management director for Palm Beach County. "We see the damage the wind does, and we pay a lot of attention to that, but unfortunately we don't pay attention to the real killer, and that is water."
Drivers underestimate the power and depth of floodwater. Just 6 inches of fast-moving water can knock down an adult, according to the National Weather Service. A foot of water can carry away a small car. And it's usually impossible to gauge the depth of floodwater.
"After a storm, the water doesn't look deep," Johnson said. "When the road signs are down, it's even harder to determine where the road ends and where the canal begins."
(This story was produced by the Florida Climate Reporting Network, a multi-newsroom initiative that includes the South Florida Sun Sentinel, the Orlando Sentinel, The Palm Beach Post, the Miami Herald, WLRN Public Media and the Tampa Bay Times.)
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