METHODOLOGY IN CALCULATING ACE POINTS:

[Audrey2Katrina]

I have followed hurricanes since 1957 (Hence the Audrey in the name--should be Audrey to Ida by now)... and I've learned a lot about accumulated cyclone energy, or ACE. This is often used NOW to make it seem they're so much higher now than in the past, and yet, I noticed for the ACE they are giving 2023, the total INCLUDES a January storm it took them 4 or 5 months to recognize, and will include any up to January 1. I don't know and I trust some of the experts can answer this for me. I checked the records for 2005 which, depending on source, grants the season either 249 or 245.3 points. However in checking the archives at Colorado State U. Atmospheric Science archives. They didn't show anything before June 1, (and maybe there wasn't) but they STOPPED on October 31 with Beta. I KNOW there was a Delta, a Gamma, a Hurricane Epsilon, and another TS. Zeta, NONE of which are calculated into 2005's ACE total. Were those four storms added (I looked at dates and times as named storms) the ACE total would be close to or over 280--surpassing 1933. Now while some will think this is a "my year was worse than yours" post, it really isn't. I could care less, if anything I was pleased to see some of the high ACE scores so long ago. But what I would like to know is -- is there a reason why they cut off the ACE for 2005 at October 31? Meanwhile this year which should be considered "near normal" at best, they count ACE from a January thing, and will, should it occur which I doubt, count any right on up to Dec. 31. This makes ACE comparisons somewhat irrelevant. Not the ACE scores... but the ACE comparisons. Can someone explain why? https://tropical.colostate.edu/Forecast/Archived_Forecasts/2000s/2005-11.pdf scroll down to table 1, and note how they stop ACE points at Beta.

[USTropics]

I have followed hurricanes since 1957 (Hence the Audrey in the name--should be Audrey to Ida by now)... and I've learned a lot about accumulated cyclone energy, or ACE. This is often used NOW to make it seem they're so much higher now than in the past, and yet, I noticed for the ACE they are giving 2023, the total INCLUDES a January storm it took them 4 or 5 months to recognize, and will include any up to January 1. I don't know and I trust some of the experts can answer this for me. I checked the records for 2005 which, depending on source, grants the season either 249 or 245.3 points. However in checking the archives at Colorado State U. Atmospheric Science archives. They didn't show anything before June 1, (and maybe there wasn't) but they STOPPED on October 31 with Beta. I KNOW there was a Delta, a Gamma, a Hurricane Epsilon, and another TS. Zeta, NONE of which are calculated into 2005's ACE total. Were those four storms added (I looked at dates and times as named storms) the ACE total would be close to or over 280--surpassing 1933. Now while some will think this is a "my year was worse than yours" post, it really isn't. I could care less, if anything I was pleased to see some of the high ACE scores so long ago. But what I would like to know is -- is there a reason why they cut off the ACE for 2005 at October 31? Meanwhile this year which should be considered "near normal" at best, they count ACE from a January thing, and will, should it occur which I doubt, count any right on up to Dec. 31. This makes ACE comparisons somewhat irrelevant. Not the ACE scores... but the ACE comparisons. Can someone explain why? https://tropical.colostate.edu/Forecast/Archived_Forecasts/2000s/2005-11.pdf scroll down to table 1, and note how they stop ACE points at Beta.

Klotzbach is many things and worldly talented, but that would have required fore telling the future, since the summary was posted on November 18 (and those systems occured at the end of November/December). Those ACE vales hadn't occured yet in the summary you linked, but the archived ACE value by season accurately accounts for those systems:

https://tropical.atmos.colostate.edu/Re ... thatlantic

You are correct, there were no preseason storms in 2005 (Arlene in June was about it before a busy and historic July). It's not uncommon to include preseason/postseason storms (and they have negligible contributions to ACE in the grand scheme of things).

[al78]

Firstly the seasonal summary was published before several of the late season storms formed which is why the report misses the last few of them. Secondly, what you claim is ACE is not ACE, it is Net Tropical Cyclone Activity (NTC) which is a different metric to ACE. Clearly Phil didn't amend the report post-season.

[1900hurricane]

This is the season total ACE (and a few other metrics) for the 2005 NAtl season, including breakdown per storm.