However, it’s not uncommon for storms to increase later in the summer, after ocean waters have warmed more and can fuel large, churning storms. The Atlantic hurricane season officially runs from June 1 to November 30, although it peaks between mid-August and October, when 90 percent of tropical storm activity usually occurs.
Thursday’s forecast was based in part on a climate pattern called La Niña, which has been in effect intermittently since 2020 and affects several aspects of the weather, including extending drought in the western United States. La Niña conditions could “improve Atlantic hurricane activity,” Mr. Rosencrans said, in part because of changes in wind direction and speed.
Scientists have documented a number of ways that climate change alters cyclonic storms, making them more powerful and destructive. Hurricanes bring greater amounts of rain, which can exacerbate flooding. And because warmer waters feed hurricanes, the zone in which these storms can form also expands from the tropics and into subtropics and the mid-latitudes.