Cape And Li

[Wet'n'Dry]

This might be a bit of a NOOB question, but how is CAPE and Lifted Index measured? I can understand how the other weather parameters are done but how about these?

If the answer is relatively simple, is it possible to DIY?

Do personal weather stations off the counter have this ability?

Thanks in anticipation ...... of a stormy 2011 :lol:

[Thundery wintry showers]

This site is pretty good:

http://weatherfaqs.org.uk/node/142#CAPE

Hopefully it should cover all you need to know.

[A.J]

This might be a bit of a NOOB question, but how is CAPE and Lifted Index measured? I can understand how the other weather parameters are done but how about these?

If the answer is relatively simple, is it possible to DIY?

Do personal weather stations off the counter have this ability?

Thanks in anticipation ...... of a stormy 2011 :lol:

The cynic in me has found an easy way to measure and calculate CAPE & L.I

During the summer months, analyse the CAPE & LI charts on the GFS model for T48 onwards, and subtract at least 1500 from the estimated CAPE value, and add at least 7 to the negative LI figure, and when reality hits a few days later, you won't be far off the mark!...........I'll fetch my coat!

[Wet'n'Dry]

Thanks Guys, much appreciated. It would seem I have a lot to read and digest !!

[johnholmes]

This might be a bit of a NOOB question, but how is CAPE and Lifted Index measured? I can understand how the other weather parameters are done but how about these?

If the answer is relatively simple, is it possible to DIY?

Do personal weather stations off the counter have this ability?

Thanks in anticipation ...... of a stormy 2011 :lol:

hi

The short answer to your 2 questions is no, or at any rate not to my knowledge!

Certainly the link TWS provided is first class. Perhaps well worth saving the link as it has a mine of information much of it initially provided by a retired senior forecaster in UK Met.

This site on Net Wx may help you with basic skew-t explanations. I am afraid 1 or 2 diagrams are still not linking as they should. If you have any questions please pm me and I will try and help.

http://forum.netweat...kew-t-diagrams/

jh

Edited April 12, 2011 by johnholmes

[Coast]

The Wiki explanation is quite good:

http://en.wikipedia.org/wiki/Convective_available_potential_energy

http://en.wikipedia.org/wiki/Lifted_index

and here from NOAA:

http://www.spc.noaa.gov/exper/mesoanalysis/help/begin.html

As well as the excellent tutorial by John Holmes here on NW, there is this one too:

http://www.atmos.millersville.edu/~lead/SkewT_HowTo.html

I always like these Skew T's as they have values and probabilities alongside to help you judge potential:

Here are some of the values to keep in mind:

http://www.skystef.be/storm-indices.htm

http://www.skystef.be/forecast20m.html

[knocker]

Rather than doing 15 tours of the internet what has happened to the old fashion idea of buying a good book that covers the subject? I do realise that books are a bit of a taboo subject these days.

[A.J]

Rather than doing 15 tours of the internet what has happened to the old fashion idea of buying a good book that covers the subject? I do realise that books are a bit of a taboo subject these days.

The internet's free yet science books cost a small fortune perhaps??

[Coast]

I think it is the freely available and often numerous sources that the internet brings (and instantly) that does it for me. I would love to sit down and read a book, but sometimes I need or want the information at my fingertips and often in a video or other dynamic format.