The first forecast for the Atlantic hurricane season for 2017 is now out.  Colorado State University issued their forecast today and it shows that they are expecting a slightly below normal hurricane season in the Atlantic Ocean basin.  This is due to the current neutral ENSO conditions, which are expected to transition into an El Niño later this summer.  When we have El Niño conditions, the strong subtropical jet stream aloft tends to “blow the top off” of developing tropical waves, keeping them from reaching tropical storm strength.  One factor which works against it is the unusually warm water in the Gulf of Mexico, which would serve as a source of energy for the storms.  This could mean an early start to the season with more Gulf storms and a decline later in the season as El Niño becomes more of a factor.  You can read about their forecast technique at Weather Underground here.