What is the term ACE mean

[boca]

In the 2008 poll some people were trying to guess what the ACE will be for the upcoming hurricane season.I remember it being explained last year in a thread. I don't remember what it stands for or what it means.

[Chacor]

Accumulated Cyclone Energy; a measure of the duration and intensity of storms. Given in ten thousand knots squared. At each full advisory or best-track point when a storm is ABOVE or EQUAL tropical storm strength (34 kt), the advisory intensity is taken and squared, then divided by ten thousand.

Therefore, a storm that lasts for one advisory as a weak TS (35 kts) will have an ACE of 35*35/10,000 = 1225/10,000 = 0.1225, while a long-lasting storm or intense hurricane will have higher ACE values.

[boca]

Thanks Chacor I appreciate the prompt response.

[senorpepr]

To piggy-back with an example: For instance, Tropical Storm Barry's best-track intensities were 30kt, 40kt, 50kt, 45kt, 40kt, and 30kt. We're only looking at advisories/best-track points at which the storm is at or above 35kt and is fully tropical. That will leave us with 40kt, 50kt, 45kt, and 40kt.

40^2/10000=0.1600
50^2/10000=0.2500
45^2/10000=0.2025
40^2/10000=0.1600

That indicates that Barry's ACE total was 0.7725 10^4/kt^2.

As a mentioned earlier, if a cyclone is sub-tropical, it does not earn an ACE score. Obviously, the stronger the storm, the quicker it racks up ACE.

40^2/10000=0.1600
140^2/10000=1.9600

Get a long-tracked, strong storm like Hurricane Ivan, and you're looking at an ACE of 70.4 10^4/kt^2.

That compares to Katrina's 20 10^4/kt^2 and Wilma's 39.01 10^4/kt^2.

[HurricaneRobert]

Here:

http://en.wikipedia.org/wiki/Talk:2007_ ... /ACE_calcs
and here
http://en.wikipedia.org/wiki/Talk:2007_ ... /ACE_calcs

Althought it's Wikipedia, so it's probably out of date

[RattleMan]

Althought it's Wikipedia, so it's probably out of date

It is not out of date. Please read things thoroughly before making such statements.

Also, to brush up on my C# programming skills, I created a program which can give you any ACE value for any number entered. Here's the most common values:

kt = ACE
---------
35 = 0.1225
40 = 0.1600
45 = 0.2025
50 = 0.2500
55 = 0.3025
60 = 0.3600
65 = 0.4225
70 = 0.4900
75 = 0.5625
80 = 0.6400
85 = 0.7225
90 = 0.8100
95 = 0.9025

100 = 1.0000
105 = 1.1025
110 = 1.2100
115 = 1.3225
120 = 1.4400
125 = 1.5625
130 = 1.6900
135 = 1.8225
140 = 1.9600
145 = 2.1025
150 = 2.2500
155 = 2.4025
160 = 2.5600

[KWT]

wow thats interesting is there anyway you could upload such a program?

[HurricaneRobert]

It is not out of date. Please read things thoroughly before making such statements.

Uh, yeah it is.

[RattleMan]

It is not out of date. Please read things thoroughly before making such statements.

Uh, yeah it is.

EDIT: Never mind, I was only looking at the Atlantic. I'll get on updating the Pacific.

EDIT 2: The Eastern Pacific is now finished.

[RattleMan]

wow thats interesting is there anyway you could upload such a program?

Sure. See here:

http://www.sonicfighters.com/rattleman/ ... Calcs.html