Double Hurricane Strikes Stem From Mix of Geography, Bad Luck

(Bloomberg) -- Cameron, Louisiana, is facing an unusual hurricane double strike, with Delta bearing down on a town that’s still recovering from Laura, which devastated the region just six weeks ago.

It might seem like that part of western Louisiana is just the victim of bad luck, considering that government weather data shows that it shouldn’t see another hurricane for 14 years. In fact, it’s happened before.

Hurricanes Frances and Jeanne in 2004 both blew through Sebastian, a small town on Florida’s east coast. The next year, southwest Florida was pummeled by Katrina and Wilma. And back in 1964, the southeast part of the state faced Cleo and Isbell within seven weeks.

Part of the reason is geography. Hurricanes don’t move under their own power -- they require larger weather patterns to shove them along. In the Atlantic, an atmospheric phenomenon known as the Bermuda high drags storms across the ocean and then can give them a northward push, so they smack into Florida or the Carolinas, which jut out into the ocean.

Weather data going back more than a century for so-called return periods shows that the Outer Banks should see a hurricane every five years, more frequently than any other part of the country, according to Phil Klotzbach, lead author of Colorado State University’s seasonal hurricane forecast.

And in the Gulf of Mexico, storms are often pulled due north toward the central Gulf Coast by weather patterns over the U.S. In fact, eastern Louisiana, right below New Orleans, is the most frequently hit part of the region, with a seven-year return period.

But western Louisiana is more sheltered and seeing two storms so quickly is unusual. Statistically, it’s unlikely to endure another one anytime soon. “The return period for Cameron Parish is going to go up a bit after this year,” said Klotzbach.

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