 The season 's activity was reflected with an accumulated cyclone energy ( ACE ) rating of 119 . ACE is , broadly speaking , a measure of the power of the hurricane multiplied by the length of time it existed , so storms that last a long time , as well as particularly strong hurricanes , have high ACEs . ACE is only calculated for full advisories on tropical systems at or exceeding 34 knots ( 39 mph , 63 km / h ) or tropical storm strength . Subtropical cyclones , including the unnamed storm as well as the initial stages of Florence , Leslie , and Michael , are excluded from the total . 
