Lessons from Hurricane Sandy on Evacuation Communications

Hurricane Sandy was an extraordinary storm on an unprecedented track for a system originating in the tropics. But in spite of a track forecast from the National Hurricane Center on Thursday, October 25, 2012, based on a consensus of the model ensembles, which would produce a life-threatening storm surge at the coast, no evacuation order was issued for New York City until three days later, midday Sunday, which gave coastal residents little time to prepare to evacuate. This paper examines what was known about the threat from the storm on each day, and how that threat might have been better characterized to convey a better understanding of the possible and/or expected coastal effects and the resulting danger. The conclusion is an evacuation communications system that would force decision makers to focus on the worst plausible outcome, which could serve as a standard for future storms, no matter the certainty of the forecast. In addition, the confusion that results from the conflict between probabilistic forecasts and required deterministic actions like evacuations is examined.