The Met Office is forecasting accumulated cyclone energy in the Atlantic above the recent average

Historic Accumulated Cyclone Energy (ACE) index marks for 2013 to 2022, and range of possible values forecast by the Met Office for 2023

ACE Index = sum of the squares of the maximum recorded wind speeds (in knots) of all storms classified as tropical storms or higher in a given season; an index value of '100' would correspond to 100 x 104 kt2
Source: UK Met Office