A satellite image from September 2017 shows Hurricane Irma, left, and Hurricane Jose, right, in the Atlantic Ocean. NOAA says the average annual number of tropical storms in the Atlantic has slightly increased.

FILE – This Thursday, Sept. 7, 2017 GOES-16 satellite image shows the eye of Hurricane Irma, left, just north of the island of Hispaniola, with Hurricane Jose, right, in the Atlantic Ocean. In a four-week span, hurricanes Harvey, Irma and Maria ravaged Texas, Florida, Puerto Rico and other Caribbean islands. (NOAA via AP)