The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 106 units, ranking it as a near-normal year. 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 ACE. It is only calculated for full advisories on tropical or subtropical systems at or exceeding 39 mph (63 km/h), which is the threshold of tropical storm strength.