There have already been a record nine named storms this season. In an average year, there might be two named storms by early August, with the ninth not forming until sometime in early October.
“This season could be one of the more active in the historical record,” said Gerry Bell, lead hurricane season forecaster at the National Oceanic and Atmospheric Administration, which put out an updated outlook Thursday.
The agency is now predicting as many as 25 named storms—the most it has ever forecast for a hurricane season, which runs from June 1 to Nov. 30. Forecasters predicted a maximum of 21 hurricanes in 2005.
Since 2010, the number of named storms and hurricanes in a season has fallen within NOAA’s forecasted range six times.
Forecasters initially predicted as many as 19 storms this season, but revised that outlook upward amid atmospheric conditions that forecasters say have become even more favorable to storm formation and intensification. Those conditions include warmer than average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, weaker Atlantic trade winds, and wind patterns off Africa that more easily spin off storms.
“These conditions are all typical evidence of an above normal and extremely active season,” Dr. Bell said.
Forecasters are now expecting as many as 11 named storms to become hurricanes this season, and three to six to become major hurricanes rated Category 3 or higher.
An average hurricane season typically has about a dozen named storms, roughly half of which become hurricanes. Three typically have winds strong enough to be rated a major hurricane.