The 2017 Atlantic hurricane season forecast from Colorado State University as updated in August 2017 called for the number of named storms and hurricanes to be above historical averages for the Atlantic Basin. A total of 16 named storms, eight hurricanes and three major hurricanes are expected this season. The 30-year average as calculated by Colorado State University is 12 named storms, six hurricanes and two major hurricanes. A major hurricane is one that is Category 3 or stronger on the Saffir-Simpson Hurricane Wind Scale.
Forecasters at the National Oceanic and Atmospheric Administration (NOAA) predicted in late May 2017 that the 2017 Atlantic hurricane season would likely be above normal, producing 11 to 17 named storms. NOAA’s Climate Prediction Center said that as many as nine of those storms could become hurricanes (with winds of 74 mph or higher) and up to four could become major hurricanes (with winds of 111 mph or higher). These numbers include Tropical Storm Arlene, a rare pre-season storm that formed over the eastern Atlantic in April. The outlook reflects NOAA's expectation of a weak or non-existent El Nino and the absence of other conditions that suppress hurricane activity. In an average season there are 12 named storms and three become major hurricanes. According to NOAA there is only a 20 percent chance of below-normal storm activity this year. The agency has new online tools to help people determine their risk from approaching storms, including more precise predictions of a storm's arrival time than have previously been available.
By September 20, 2017, 13 tropical storms had formed in the Atlantic Basin, seven of which, Franklin, Gert, Harvey, Irma, Jose, Katia and Maria, became hurricanes.
During the 2016 North Atlantic hurricane season 15 named storms formed in the Atlantic basin, seven of which were hurricanes, and four of which were major hurricanes. Hurricane Alex was just the second hurricane on record to form in the Atlantic Basin during the month of January according to NOAA.
Storms to have made landfall in the United States in 2016 are Tropical Storm Bonnie and Hurricane Matthew in South Carolina, and Tropical Storms Colin and Julia and Hurricane Hermine in Florida. Hermine was the first hurricane to make landfall in Florida since Wilma in 2005.
Hurricane Hermine made landfall in Florida on September 2 as a Category 1 storm. Hermine was the first hurricane to make landfall in Florida since Wilma in 2005.
Hurricane Matthew formed in late September and became a hurricane in the South Central Caribbean. Matthew dumped heavy rain on the Bahamas, Haiti and Cuba on October 4 and 5 as a Category 3 storm. On October 7 Matthew grazed the eastern coast of Florida, hitting the state with winds as high as 120 mph and torrential rain. The storm has carried extremely powerful winds for a longer period than any other Atlantic storm on record. Matthew made landfall in the United States on Oct. 8 near McClellanville, South Carolina, as a Category 1 hurricane. The storm caused storm surge flooding as it moved through Florida, Georgia, Virginia, and North and South Carolina. It was downgraded to a post-tropical cyclone on October 9th. The death toll from the storm is up to 46 in the United States. Estimates of insured losses for Hurricane Matthew range from $1.5 billion to $7 billion in the U.S.
Nicole became a hurricane on October 11 and struck Bermuda at category 3 strength on October 13th.
The following chart from the Property Claim Services (PCS®) unit of ISO, a Verisk Analytics® business, ranks historic hurricanes based on their insured losses, adjusted for inflation. The chart beneath it, from AIR Worldwide Corporation, estimates insured property losses from notable hurricanes from past years, if they were to hit the nation again today with the same meteorological parameters.