In New Scotland, N.Y., a woman was evacuating her home along the Onesquethaw Creek when she was swept away. In the Catskills, an 82-year-old Romanian-born Holocaust survivor died when her cabin was inundated by floodwater.
If there’s a single storm that Irene most resembled, in trajectory and impact, it may be Hurricane Floyd, from 1999. Floyd also tracked up the East Coast and, like Irene, proved less lethal than expected at the point of the spear. But its gravest impacts came days later, as floodwaters rose in North Carolina and adjacent states.
The underemphasis on precipitation doesn’t necessarily mean storm surge or wind are overhyped when hurricanes approach, said Hugh Willoughby, a Florida International University meteorologist. The most lethal hurricanes, such as Katrina in 2005 and Camille in 1969, tend to kill with storm surge, he said.
“If you kill hundreds of people, it’s almost always storm surge,” Willoughby said. But he said that most hurricanes don’t kill hundreds or even dozens of people.
“In the generic hurricane season, people drown in freshwater,” Willoughby said. “Season after season, it’s people drowning in freshwater flooding from torrential rains.”
A tragic example of hurricane-related freshwater drownings occurred when Hurricane Mitch struck Central America in 1998. Although Mitch had been a Category 5 storm, at landfall its winds were more modest. But the rainfall created flash floods that killed nearly 20,000 people, said Emanuel, the MIT professor.
Roughly half of those killed in U.S. hurricanes in the past 40 years have died in storm surges, and almost all of those fatalities were caused by Katrina, according to a recent study by Ed Rappaport, deputy director of the National Hurricane Center. Roughly one-quarter of the fatalities came from rainfall-induced flooding, he said. The rest were attributed to drowning in the surf and to wind-related incidents and tornadoes.
The key point is that every hurricane is different, and those differences are magnified by local conditions. How a hurricane will play out is something that no one can predict.
Vermont’s governor, Peter Shumlin (D), said Monday on the “Democracy Now!” radio program that climate change from the burning of fossil fuels is a factor in his state’s disaster. “We didn’t used to get weather patterns like this in Vermont,” he said.
Vermont and the rest of New England have, in fact, been pelted with many tropical storms over the decades. But Emanuel thinks Irene provides an illustration of what can be expected of such storms in a warming climate.
“Everything else being equal, hurricanes will rain more, just because they’re ingesting more water vapor,” Emanuel said.
Tom Peterson, chief scientist at the National Oceanic and Atmospheric Administration’s national climatic data center, said the damage caused by Irene should provide a warning: “Events like this routinely show us that we’re not adapted to the current climate, let alone to the future climate that we’re going to be having.”
Staff writer Jason Samenow and staff researcher Lucy Shackelford contributed to this report.