Talk:2017 Atlantic hurricane season/ACE calcs

This is the page for calculating the Accumulated cyclone energy for the 2017 Atlantic hurricane season. If any storms of a season happen to cross years, the storm's ACE counts for the previous year.

The ACE is calculated by summing the squares of the estimated maximum sustained velocity of every active tropical storm (wind speed 35 knots or higher), at six-hour intervals. The numbers are divided by 10,000 to make them more manageable. The unit of ACE is 104 kt2, and for use as an index the unit is assumed. Thus,


 * $$\text{ACE}_{2017} = \sum_{}^{} \frac{{v_\mathrm{max}}^2}{10^4},$$

where vmax is estimated sustained wind speed in knots.

Since the ACE calculation method uses data from six-hour intervals, the value for a particular tropical storm is dependent upon the starting time. The operational advisories from NOAA's National Hurricane Center (NHC) typically begin at 3 UTC, 9 UTC, 15 UTC or 21 UTC, while NHC's Best Track reports and the Colorado State University list typically begin at 0 UTC, 6 UTC, 12 UTC, or 18 UTC.