It's been days since Hurricane Sandy began to effect the East Coast of North America. Yet some of the images and stories we continue to hear come out of the most hard hit regions, like New York City and New Jersey, still shock us to the core. Most of us, including myself, have yet to fully comprehend just how such devastation could have occurred in areas that typically don't have this type of catastrophe.
Some of the statistics and effects attributed to Sandy are hard to believe as well. 180 killed across 8 countries, including 98 in the United States. Upwards of some 50 billion dollars in estimated damage done along the East Coast. A two day shutdown of the NYSE, the first time a weather related issue has forced the closer of the Exchange since an 1888 blizzard. NYC transit service coming to a halt, half of Manhattan without power. The list goes on and on.
From a meteorlogical standpoint, Sandy set some records as well. Sandy had a record low pressure for a hurricane north of Cape Hatteras, NC. At her peak size, she had tropical force winds extending out for a total of 580 miles from her center! And several high water mark records, the most notable being the 13.88 ft record height reached at Battery Park in Manhattan. With such a record breaking storm, its easy to assume that Sandy was the first of her kind. But if we look a little closer at hurricane track history, we find that Sandy wasn't that unique at all.
Umass Lowell graduate meteorology student Lance Frank compiled a record of tropical systems, dating all the way back to 1851, that all had a storm track that traveled to the west well north of Cape Hatteras, NC and occured late in the hurricane season between the months of September and October. These are very specific guidelines, especially considering how obscure this type of behavior is for a tropical system.
What he found was quite interesting. A total of 16 storms fit the criteria, with 7 of those storms making landfall somewhere along the Eastern coast of North America. Three of those storms actually made landfall in Massachusetts in 1869, 1896 and 1923.
Whats more, Sandy was not even the strongest of the this group of storms. You will notice that both the hurricane of 1938 as well as the previously mentioned 1869 storm were both stronger in terms of maximum wind speed. Lance actually went further into the historical weather data and was able to connect large scale weather patterns for each storm. I am sure most of you have heard the term "blocking" as one of the main causes for Sandy's odd track. It turns out that with just about all of these storms, a similar sort of "blocking" pattern was present, helping to push all of these systems back to the West, when they should go out to sea.
So what does this information tell us? Well, for one, it tells us the a Sandy type of storm has clearly happened before. Not all of these storms hit land and Sandy was certainly unique in both her sheer size as well as her landfall in the most heavily populated part of the country. It should also put the breaks on any premature talk of climate change influencing Sandy. It is incorrect and scientifically immoral to suggest that Sandy's destruction was driven by climate change. The fact is, we just don't know. There is not enough reliable information to connect the two.
With large scale events such as Sandy, we must deal with what we know to be true and not try to infer otherwise. Having analogous historical data like this helps immensely in understanding why Sandy did what she did and more importantly, it helps us to be able to recognize similar situations in the future which will lead to more accurate forecasting.
Regardless of any similarities to the past, Sandy's swath of destruction and devastation will be felt for many years to come, meaning we certainly won't be forgetting this Hurricane anytime soon.
