October 30, 2012

Storm surge flooding has slowed Manhattan and other parts of New York City to a halt following last night's landfall of Hurricane Sandy. The lowest-lying areas of the five boroughs — the so-called "Zone A" — were uniformly and completely inundated. Some Zone B areas also experienced devastating water events, including the Lower East Side.

Dr. Tom Jeffery, chief hazard scientist for CoreLogic, an company that analyzes potential storm surge impacts, says that the 13-foot storm surge is just about the most possible from a storm of Sandy's magnitude — a Category 1 hurricane.

"This is one of those cases where you have the worst possible combination of events occurring," he explains. "There's been a recent push to not talk about categories, but the amount of surge that was generated was right in the area that you would expect for a Category 1."

Sandy was unique because it didn't weaken upon reaching landfall, Jeffery adds. The combination of the tropical cyclone with a northeaster created an environment that kept winds churning up water for much longer than the average Category 1.

"Usually with tropical storms they tend to ramp down very quickly, but when the storm merged with the northeaster it didn't lose any of its strength," he says. "Even the winds that were trailing maintained more than 70 miles per hour."

A silver lining is that modelers now have more data about the potential effects of this type of storm on the eastern seaboard going forward, Jeffery concludes.

ABOUT THE AUTHOR
Nathan Golia is senior editor of Insurance & Technology. He joined the publication in 2010 as associate editor and covers all aspects of the nexus between insurance and information technology, including mobility, ...