Highest combined accumulated cyclone energy on record


The 2018 Atlantic hurricane season became the most recent season to feature four simultaneous named storms, after 2008. Visible in the image is Florence (left), Isaac (bottom center), Helene (lower right), and Joyce (upper right) on September 12.
From page: https://en.wikipedia.org/wiki/2018_Atlantic_hurricane_season

This year featured a very extensive pacific hurricane season featuring 10 major hurricanes in combination with a reasonably busy Atlantic hurricane season, resulting in  the highest combines accumulated cyclone energy on record.

Accumulated cyclone energy is a measurement based on the square of the sustained 1 minute winds (in knots) squared divided by 10,000 this is added every 6 hours to give a profile where as a long duration powerful storm has a higher accumulated cyclone energy than a shorter lived, or less powerful storm. 

The Pacific season ended with a new record value of 318 units, where as the Atlantic season had a still high, but no where near record breaking value of 127.  The previous highest value on record for the Pacific season (East of 180 degrees) was 295 in 1992, the record for the Atlantic basin is 250 from 2005.

As a general rule when there is a strong hurricane season in one basin, there is a diminished season in the opposing basin, but this year that did not seem to hold true, as you can see from the graph.

ACE graph by year, 1971-2018

The Yellow trend line is trending higher than ever, although with the limited data set and the exaggerating factor of having the highest totals in the years where it is weighted most highly towards current season that would be expected.  Even without that the last four years of have some of the highest total ACE values of any years on the graph, with the margin for 2018 above the previous combined record holder (371 in 1992) is 74 points of ACE, which is a higher value than several single basin values in the data set and even beats the value for both basins in the particularly slow year of 1977.

Below I have included the full data set that I used, the formula for the trend lines, and data sources.

Appendix A

PacificAtlanticTotalTrend
197113997236207.1429
197213636172182.4444
197311448162173.2
19749068158170.9
197511276188168.7
197612184205171.8
1977222547147.6
197820763270190.5
19795793150181.1
198077149226201.1
198172100172189.9
198216132193206.5
198320617223228.4
198419384277245
198519288280234.9
198610736143197.1
198713234166193.5
1988127103230222.7
1989110135245250.4
199024597342288.7
199117836214276.7
199229576371295.1
199320139240267.7
199418532217259.2
1995100227327262.8
199653166219247.9
199716741208249.6
1998134182316264.7
199990177267253.6
200095119214229.8
200190110200211.2
200212468192214.6
200356177233245.8
200471227298277.6
200596250346280.7
200615579234240.7
20075274126195.4
200883146229197.2
200912553178196.8
201049165214216
2011118126244215.6
201298133231211.5
20137636112203.4
201419867265253.9
201528763350301.5
2016183141324335.6
2017100225325354.2222
2018318127445393.4286

Appendix B

Trend lines are based on the current season times four, plus the Previous season and following season times two, plus two seasons hence, and two seasons following, all summed and divided by ten.  

If the current season is season three, the formula would be {season one + (2 x season two) + (4 x season three) + (2 x season four) + season five} / 10

At the end members of the data set the end members of the trend line were truncated, ie on season two, season 0 was removed (as no data exists) and the total was divided by 9 rather than ten since the summed total only accounted for 9 season units.

Appendix C

Sources:

https://en.wikipedia.org/wiki/Accumulated_cyclone_energy

https://en.wikipedia.org/wiki/2018_Atlantic_hurricane_season

https://en.wikipedia.org/wiki/2018_Pacific_hurricane_season

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