With two months left to go in the Atlantic hurricane season, we’ve already had a hurricane season we’d like to forget. August and September featured eight hurricanes, five of which reached major hurricane criteria (Category 3 or stronger). Two directly impacted the mainland U.S (Harvey brought devastating flooding to Texas and Louisiana, Irma left widespread power outages and flooding in Florida and Georgia), while Maria was the most destructive hurricane to strike Puerto Rico in 90 years. But still, as active as this season has been, it’s not over yet. And people along the Gulf Coast should take particular note of October, and where storms typically form this month.
Hurricane predictions at the beginning of the summer are largely based on climatology, or what has happened over the last 30 years or so. They can give us a look at whether a particular hurricane season will be near, above or below average. It can’t, however, predict when and where storms will make landfall. We can look to monthly climatological normals to best predict where tropical cyclones (tropical storms and hurricanes) could form and where they might go. A handy resource for this info is, of course, the National Hurricane Center. They have compiled data that goes back to the 1850s to show where hurricanes started and where they ended up. Now, most of the data collected before the satellite era of meteorology (1960s) is based on reports from mariners and island residents on the open waters of the Atlantic, Gulf of Mexico and Caribbean Sea.
You’ll see from the charts below that the Gulf of Mexico and northern Caribbean Sea, during the month of October, are fertile breeding grounds for tropical cyclone formation. One reason this is the case is the increased number of cold fronts that make it down into the Gulf and Caribbean. The tail end of these fronts can create localized areas of low pressure, that can then turn into larger areas of low pressure and take on tropical characteristics. This is why people along the Gulf Coast, including Alabama, should keep a heads up to what’s happening in the tropics and be prepared if a tropical storm or hurricane moves this way. Of course, the Storm Track Weather Team will keep you up to date if and when that happens.