2018 hurricane season wraps up with above-average activity

Scientists at the National Oceanic and Atmospheric Administration published their end-of-season summary on Wednesday, marking an unofficial end to an active Atlantic season that spun two devastating storms toward the shores of the continental U.S.

The above-average season, which officially ends Friday, will conclude with 15 named storms, eight hurricanes, of which two were major, which means Category 3 storms or higher with a wind speed of at least 111 mph. An average season has 12 storms, six hurricanes, two of which are major. No tropical cyclone activity is expected in the last two days of the season, according to the National Hurricane Center.

The most notable storms of the season were hurricanes Florence and Michael. Florence, once a major hurricane, weakened before stalling above the Carolina coast in September, dumping a massive amount of rain that caused devastating river flooding. Michael, which came weeks later, intensified rapidly to near Category 5 strength before slamming into Mexico Beach on Oct. 10, reducing most of it to rubble. It was the strongest storm on record ever to hit the Panhandle and had the third lowest central pressure and fourth highest wind speed of any storm ever recorded to hit the continental U.S.

More than 50 people died as a result of Florence, according to news reports. At least 40 deaths have been attributed to Michael.

Among the reasons the season turned out to be more active than normal are the lack of El Nino and warmer-than-average ocean temperatures in the Atlantic, the NOAA report said. El Nino, which is a phenomenon of warmer-than-normal water temperatures in the tropical Pacific Ocean, causes high-level winds to sweep across the tropical Atlantic, making it harder to storms to coalesce into dangerous cyclones. But that didn't materialize, the scientists wrote. And warmer Atlantic temperatures just fuel storms, which feed off warm water.

This year was the fourth in a row that hurricane activity developed before June 1, the official start to hurricane season. Tropical Storm Alberto threatened Florida's Memorial Day weekend before making landfall near Laguna Beach in the Panhandle.

Contact Josh Solomon at jsolomon@tampabay.com or (813) 909-4613. Follow @ByJoshSolomon.