How to calculate CAPE?

[Aric Cylkowski]

Been trying to find a good method of calculating CAPE. If anyone can help me out, I would gladly appreciate it.

 

[Jeff Snyder]

You can't really do it w/o the help of a computer. If you look at a ton of skew-Ts, you can probably begin to eyeball/estimate CAPE pretty well. I suppose you could print out a skew-t and use tiny pieces of paper to "estimate CAPE" by doing some "calibration" beforehand. For example, all the paper shreds equal 5000 CAPE, so if you only use 1/2 of the scraps to fill in the area between the parcel trace and the environment, then you could estimate the sounding (for the parcel you choose) to have about 2500 j/kg CAPE. I suppose you could use your calculator to numerically solve for CAPE by going through LFC to EQ at, say 250m increments), but that's not really practical.

 

[Scott Olson]

Here is a method:

http://bangladeshtornadoes.org/liftedcalc.html

 

[Jeff Snyder]

Originally posted by Scott Olson
Here is a method:

http://bangladeshtornadoes.org/liftedcalc.html

Scott,

That page describes how to "forecast" the Lifted Index (LI), not CAPE. Just FYI

 

[Glen Romine]

You can rather easily calculate LI though - and it is a quite reasonable ballpark surface-based instability estimate for the typical sounding. Plenty of resources on the web for how to calculate this (do a google search). Reality is that there is insignificant value in getting exact CAPE calculations - to the nearest 500 J/Kg will do most days, and LI for a typical environment can get you that level of accuracy.

Glen

 

[Scott Olson]

Originally posted by Jeff Snyder+--><div class='quotetop'>QUOTE(Jeff Snyder)</div>

<!--QuoteBegin-Scott Olson

Here is a method:

http://bangladeshtornadoes.org/liftedcalc.html

Scott,

That page describes how to "forecast" the Lifted Index (LI), not CAPE. Just FYI [/b]

I know, it's for the LI but figured it might be helpful.

 

[Chris Lott]

Maybe this will help.


http://www.eos.ubc.ca/courses/atsc201/A201...adings.html#ESO

Once you click this link, down near the bottom of the page it explains how to calculate CAPE.

 

[Bobby Eddins]

Here's another with a fomula. Pan down and look for CAPE.
http://www.crh.noaa.gov/lmk/soo/docu/indices.htm

 

[Aric Cylkowski]

Thank you guys for the help.