European indecies in RAOB

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Dave Exton
Posts: 63
Joined: Tue Aug 31, 2004 9:17 pm
Location: Bristol, UK

European indecies in RAOB

Post by Dave Exton »

Can anybody give an an enthusiastic amateure any help with the European fog and storm indecies. The only one I know is the Boyden Index (+94/95 =risk of thunder).

Any help would be appreciated.


Dave Exton, UK. :?

Tom Ehrensperger
Posts: 10
Joined: Fri Jan 02, 2004 11:37 pm
Location: College Park, Georgia, USA

Post by Tom Ehrensperger »

Hi Dave,

I know of Boyden and another called the KO Index, having learned about them from European users of my WXSIM program. Here's what I have (from WXSIM's help files):

" The Boyden Index is a stability index tailored for"
" use in cool, moist climates such as Northwestern"
" Europe. It is defined as:"
" "
" (h7 - h0)/10 - t7 - 200"
" "
" where (h7-h0) is the thickness of the 1000-700 mb"
" layer in meters and t7 is the temperature at 700 mb"
" in Celsius. It is especially useful with cloudy con-"
" ditions near fronts, when values of 94 or greater"
" imply probable thunderstorms."

" The KO Index is a stability index tailored for use"
" in cool, moist climates such as Northwestern"
" Europe. It is defined as:"
" "
" (e5 + e7)/2 - (e8 + e0)/2"
" "
" where the e's are the equivalent potential tem-"
" peratures at 500, 700, 850, and 1000 mb. Values"
" over +6 suggest little if any shower activity, while"
" values <1 imply probable thunderstorms."

Hope that helps!


Jan Hoeher-Larsen
Junior Member
Posts: 5
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Location: Denmark

Post by Jan Hoeher-Larsen »

Posts: 65
Joined: Fri Nov 28, 2003 5:54 pm

Re: European indecies in RAOB

Post by JohnShewchuk »

The RAOB Program produces these 3 European thunderstorm indices: Boyden, KO-Index, and the S-Index.

The RAOB Program also produces these 3 Fog indices specifically developed for Europe: Fog Stability Index (FSI), Fog Threat, and Fog Point. And there is now a new Fog Table capability, where you can analyze both Advection and Radiation fogs, and tailor them to any worldwide region or season >

All indices are explained in detail in the RAOB User Manual >


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