WASHINGTON, D.C. (WUSA) - The number and frequency of hurricanes falls off dramatically after the September peak of the season. While the hurricane season runs through November 30th in the Atlantic Ocean Basin (including the Gulf of Mexico and Caribbean Sea) September is the busiest month because conditions are ideal for hurricanes to form. That's not to say that significant storms don't form in late October and November, they are just less common. Over the last 13 years, there have been three memorable late October storms.
On October 26, 1998, Hurricane Mitch became the Atlantic Ocean's first Category 5 hurricane since Andrew in 1992, with sustained winds up to 180 mph. Conditions were ideal with exceptionally warm ocean water, well above the 80 degree Fahrenheit threshold for hurricane development. Since the prevailing wind pattern was weak and didn't steer the storm away, Hurricane Mitch was left to slowly meander around the southwest Caribbean Sea. That led to severe flooding in Central America that unfortunately caused widespread devastation and a tragic loss of over 11,000 lives.
During the record setting 2005 season, the strongest hurricane ever recorded in the Atlantic Ocean formed in almost the same spot as Hurricane Mitch. Once again, atmospheric conditions were ideal for rapid intensification of the hurricane with extremely warm ocean water. Hurricane Wilma became a Category 5 hurricane on October 19, 2005 with sustained winds of 185 mph. Winds gusted over 200 mph around the center of both Mitch and Wilma. Wilma's lowest observed air pressure was 882 millibars. By comparison, Hurricane Mitch's lowest air pressure was 905 millibars. The lower the air pressure, the stronger the storm is.
Category 5 hurricanes are truly rare storms and even those that do form don't usually stay at that intensity for very long. According to the National Hurricane Center, the Atlantic Ocean Basin has not seen a Category 5 hurricane since Hurricane Felix in 2007. On the Saffir-Simpson hurricane intensity scale, a Category 1 hurricane has sustained winds of 74 mph - 95 mph around the center of the storm, while a Category 5 storm has sustained winds of at least 156 mph.
Just this past week, Hurricane Rina formed in the western Caribbean Sea. It became only a Category 2 hurricane, with maximum sustained winds reaching 110 mph, before it weakened as it interacted with Central America. Part of the reason why the western Caribbean is such a favorable area for tropical storms and hurricanes to form is because the water remains very warm for much of the year. Unlike the Gulf of Mexico farther north, cold air rarely makes it far enough south to reach the Caribbean. So it's important to note that, while a multitude of factors play a role in the development of a hurricane, there is one particular area in the Atlantic Ocean Basin where conditions are more favorable for longer than any other region. And that's in the western Caribbean Sea.
The 9 News Now team of meteorologists will continue to track any tropical storms or hurricanes that develop and bring you the latest weather information and forecasts, both on-air and online.