Despite projections to the contrary, the 2013 Atlantic hurricane season has largely been a dud — and there’s no sign that will change any time soon. Tropical Storm Karen briefly threatened the Gulf coast this weekend, but by Sunday it was clear that the storm was weakening, and the National Hurricane Center — understaffed because of the government shutdown — issued no coastal warnings or watches because of the storm. We’re also at eight years and counting without a major — Category 3 or above — hurricane making landfall in the U.S. (Sandy, for all the damage it caused, was never a major hurricane and wasn’t even a hurricane, officially, when it did make landfall.)
Why have there been so few storms so far this year? First of all, there have been storms — 11 named storms so far, which is about average for this time of year. But those storms have been weaker than average — only two, Humberto and Ingrid, were classified as hurricanes — and none of them have yet made landfall. A Texas A&M University researcher suggests the weakness of those storms might be because of unusually dry air.
Robert Korty, an associate professor of atmospheric science at Texas A&M University, notes that August and September, usually very active months for tropical storms, were especially quiet:
If you had to point to one reason, it would be dry air. The dry air coming across the Atlantic from Africa prevented a lot of storms from developing during August, and the ones that did develop were not very strong. So the result has been a hurricane season of about normal in number of storms, but these have been relatively weak ones so far.
What this means, really, is that we’ve been lucky. The historically active 2005 hurricane season — which featured 28 total storms and seven major hurricanes — was less than 10 years ago. The effect that climate change will have on hurricane intensity and frequency is less than clear. The recent report from the Intergovernmental Panel on Climate Change (IPCC) found low confidence that there will be climate-change-caused increases in tropical storms, though other studies — completed too late to be included in the IPCC report — differ. But we do know that sea levels will keep rising, which increases the danger from storm surges, and the growing density of people and property along the coasts will amp up the potential damage a storm can cause. Over the long term, the odds aren’t in our favor.