The residents of Moore, Oklahoma are still cleaning up from the EF5 tornado that tore through their town on May 20. 24 people died in the twisters, and thousands of homes and buildings were damaged or destroyed. The total bill may come in at over $2 billion, which would make the Moore tornado the most expensive in American history.
So this may not be the best time, but the Moore tornado almost surely won’t be the last billion-dollar weather the U.S. faces in 2013. On Thursday the National Oceanic and Atmospheric Administration (NOAA) released its annual outlook on the summer Atlantic hurricane season—and it is not good. Technically it will be “active or extremely active,” which is fine if you’re talking about a workout session, and less good if you’re projecting how many potentially devastating tropical storms will hit the U.S. mainland.
Altogether NOAA predicts a 70% likelihood that 13 to 20 named storms—which have winds that sustain at 39 mph or higher—will occur, of which 7 to 11 could become hurricanes (winds higher than 74 mph). Of those three to six may become major hurricanes, which means Category 3 to 5, with winds above 11 mph. That’s all well above the average for an Atlantic hurricane season, which lasts from June 1 to the end of November.
Why will this summer potentially be so stormy? For one, an atmospheric climate pattern, including a strong African monsoon, that’s been ongoing since 1995 will help supercharge the atmosphere for tropical storms. Warmer-than-average water temperatures in the tropical Atlantic and the Caribbean Sea will lead to more of the wet, hot air that provides the fuel for hurricanes. And there is no El Nino—the alternating climate pattern that means unusually warm sea temperatures—which would usually suppress the formation of hurricanes.
It’s important to remember that NOAA is only predicting whether or not hurricanes and tropical storms will develop—not whether they will make landfall like Superstorm Sandy did last fall. Only three of the 19 named storms that formed in the Atlantic last year made enough of an impact on the U.S. to cause any real damage. Most storms form in the Atlantic and never leave. It’s not just the strength of a storm that makes it dangerous—it’s location.
Superstorm Sandy made that clear. By the time storm made landfall on the East Coast, it had actually weakened to the point that it was barely a hurricane at all, though it was an unusually massive and wet storm. Had it spun back out to sea, we never would have remembered its name. Instead, though, Sandy tore through the most populated and expensive property in the U.S., flooding parts of New York City and causing some $65 billion in damage. We can only imagine what kind of destruction it would have caused had Sandy been an even stronger storm.
There’s no way of knowing how many of the storms to come this summer will indeed make landfall, but it stands to reason that the more storms that form, the greater the chance one will eventually end up in our backyard. According to NOAA, billion-dollar disasters are increasing in the U.S. at a rate of about 4.8% a year—there were 11 just last year. That’s mostly a result of economic growth—as the country gets richer, even with inflation, any weather disaster that disrupt the economy will cost more. But climate change is likely playing a role as well—in the case of hurricanes, warming temperatures seem to make storms stronger, and rising sea levels increase the threat of coastal flooding.
In any case, the growing danger from extreme weather just underlines the need to invest in forecasting, preparation and adaptation, as acting NOAA Administrator Kathryn Sullivan said:
With the devastation of Sandy fresh in our minds, and another active season predicted, everyone at NOAA is committed to providing life-saving forecasts in the face of these storms and ensuring that Americans are prepared and ready ahead of time.” said Kathryn Sullivan, Ph.D., NOAA acting administrator. “As we saw first-hand with Sandy, it’s important to remember that tropical storm and hurricane impacts are not limited to the coastline. Strong winds, torrential rain, flooding, and tornadoes often threaten inland areas far from where the storm first makes landfall.
Of course, if you really want to worry, remember that last year NOAA predict that the Atlantic hurricane season would be just a little above normal. It ended up being considerably more active. But there’s one thing we can be sure of—there won’t be another Hurricane Sandy. That name has been retired.