The tropics have been churning up trouble all season long from the Gulf coast to the Caribbean and even the eastern seaboard. Here is the tropical season by the numbers... so far.
The Atlantic basin has spun up 15 named storms and more than fifty percent of those storms have been hurricanes. Five of those hurricanes have been considered a major hurricane, which means a category three storm with winds in excess of 111 mph. With all this activity to the south, curiosity begs the question: Has it influenced our weather at all recently? The simple answer is yes.
This hurricane season has been unlike any other this year, but it still only ranks as the third most active season on record. There are a lot of ingredients that go into an active season in the Atlantic. For the specifics on what it takes for a hurricane to spin up, we talked to Todd Shea, the Warning Coordination Meteorologist at the National Weather Service in La Crosse. "You need the warm ocean temperatures. You need the right air flow in the atmosphere, which is just of perfect in the tropics. And for some reason this year, we've had these thunderstorm complexes that come off the coast of Africa and they've been coming across maybe warmer than normal ocean temperatures as they move west toward the United States.
The accumulated cyclone energy, which measures the combined strength and duration of tropical storms and hurricanes ranks this September as the most active on record. Shea speaks to that point by saying, "...five major hurricanes so far this season. The first one with Harvey just came right up out of the Gulf and was a big rain producer. The others: storm surge, rain, and wind. So it's been a combination of threats between the different storms as well."
The big question is whether or not it has any impacts on our weather patterns. The local weather scene has been a little off kilter compared to the 30 year climatology. Cynthia Berlin, the Department Chair for Geography and Earth Sciences was able to talk about the extremes we have experienced this summer. "One of the things we're finding is that the extremes have increased. And it's not that drought is unusual, it's just that it's more frequent or the rain events may be a little more frequent or extreme."
The abundance of activity in the Atlantic basin might be partially to blame for our local extremes. The weather pattern becomes stagnant resulting in the same weather feature staying overhead for a longer period of time. Shea said, "The only real contribution we've seen is a little bit of what we call the blocking. So weather patterns weren't able to migrate or change quite as much as they could."
There are still seven weeks left in the tropical season, so the third most active season on record has the potential to still jump a spot or two. It was just yesterday a new tropical storm, Ophelia, formed in the Atlantic. This makes for the 15th named storm this year. Ophelia is expected to be a weak hurricane by Friday morning, but it will stay a "fish storm" and steer clear of the United States coastline.
This year the Atlantic has produced three category five hurricanes this year including Harvey, Irma, and Maria. Hurricane Irma was the strongest hurricane ever recorded in the Atlantic with winds reaching more than 185 mph for nearly forty consecutive hours.