Believe it or not, it's been nine whole years since North America was struck by what meteorological experts consider a "major" hurricane. Experts at NASA determined that such a long dry-spell is likely to occur only once every 177 years. So what has caused it? It could just be luck.
We should first point out that the space agency's experts and their colleagues with the National Hurricane Center are by no means saying that recent hurricanes like Sandy were not "major" in their own right. Superstorm Sandy tragically took the lives of at least 233 people across eight countries, left countless homeless, and cost the world nearly 70 billion in estimated damages. And that's all from a Category 2 storm, with sustained winds of 96 to 110 mph, when it made landfall along the North American coast.
"Major storms," however, are considered Category 3 or higher. While Sandy was accompanied by immense rainfall and flooding, making it a devastating force along shorelines, Category 3 storms can be destructive just by their winds alone. The force of these major storms can maintain wind speeds approaching 130 mph, even while crossing over dry land - something that normally takes the kick out of a wandering hurricane.
The result is, assuredly, that "devastating damage will occur," according to the NOAA. There is no stopping these storms. Instead, residential areas bunker down or evacuate, and prepare to rebuild.
"Power outages will last weeks to possibly months," the agency added. If a major storm approaches Category 4 (winds 130mph+), "most of the area will be uninhabitable for weeks or months."
In that light, it is a very-very good thing that North America hasn't seen one of these storms in nearly a decade. But what gives? Have we just been lucky so far? (Scroll to read on...)
[Credit: NASA's Goddard Space Flight Center ]
Timothy Hall, a research scientist who studies hurricanes at NASA's Goddard Institute for Space Studies, recently teamed up with Kelly Hereid, of CE Tempest Re, a reinsurance firm based in Connecticut, to design and run a statistical hurricane model based on a record of Atlantic tropical cyclones from 1950 to 2012.
The researchers ran 1,000 computer simulations in all, looking at known storms and hurricane conditions (sea surface temperature data, etc.) in order to best see 63,000 separate Atlantic hurricane seasons. They found that a nine-year period without a major landfall is likely to occur once every 177 years on average.
"The last nine hurricane seasons were not weak - storms just didn't hit the US," Hall added in a statement. "It seems to be an accident of geography, random good luck."
Still, many experts are uncomfortable simply attributing this drought of hurricane landfalls to just dumb luck. After all, these nine years immediately followed the hurricane Katrina season - the most active Atlantic hurricane season on record - when the Category 5 that devastated New Orleans was also preceded by hurricane Dennis (C4) and followed by hurricanes Rita (C5), and Wilma (C5).
In many ways, this make those nine years the calms after the storms. But what does this mean for things to come? With other research pointing to the idea that climate change is fundamentally shifting how and when extreme weather occurs around the globe, some have argued that warming waters in the north may be directly leading to more, or even fewer hurricane storms. Hall explained that it all remains a very inexact science.
"Hurricanes respond in complicated ways to their environment," he said. "It's one of the areas of climate change research where reasonable people can still disagree."
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