Script (Totals Total Index)TT

[Peter Bartlett]

Gents,

Here is another Stability Indices, hope its of use (TT Index)

Total Totals Index (TT)

TT = T850 + Td850 - 2T500

CONT GRTN=44 CINT=2 DASH COLOR=200100 SSUM= 5:6 STOR=6 SDIF 3:4 STOR=5 SDIF 1:2 STOR=4 TEMP H500 STOR=3 DWPT H850 STOR=2 TEMP H500 STOR=1 TEMP H850

The risk of severe weather activity is defined as follows:

44-45 Isolated moderate thunderstorms
46-47 Scattered moderate / few heavy thunderstorms
48-49 Scattered moderate / few heavy / isolated severe thunderstorms
50-51 Scattered heavy / few severe thunderstorms and isolated tornadoes
52-55 Scattered to numerous heavy / few to scattered severe thunderstorm / few tornadoes
> 55 Numerous heavy / scattered severe thunderstorms and scattered tornadoes

[Weasel]

Thanks for the script, Peter!

Pat

[Fred]

Hello Peter

Nice script, thanks. While adding some commands for showing the ranges in colour I noticed some things.

The first range is 44-45. So I thought that if you test for GRTN (greater than) 44 you miss the first part. So I changed the command into GRTN 43. WRONG!! It turned out that GRTN means “greater and equal than”. I did not test the meaning of LSTN. Is it also “less and equal than”?

Another thought. In the formula some slots are subtracted from each other. What happens if the result is negative (remember the problems with the TEMP-scripts (below zero)). I don’t know how to test this. Anybody has an idea?

The script:
ERASE
ANALYZE,SSUM= 5:6 STOR=6 SDIF 3:4 STOR=5 SDIF 1:2 STOR=4 TEMP H500 STOR=3 DWPT H850 STOR=2 TEMP H500 STOR=1 TEMP H850
ANALYZE,OVER FILL COLOR=255:255:100 FILS=0 GRTN=44
ANALYZE,OVER FILL COLOR=255:240:000 FILS=0 GRTN=46
ANALYZE,OVER FILL COLOR=255:204:000 FILS=0 GRTN=48
ANALYZE,OVER FILL COLOR=255:161:000 FILS=0 GRTN=50
ANALYZE,OVER FILL COLOR=255:097:000 FILS=0 GRTN=52
ANALYZE,OVER FILL COLOR=255:014:014 FILS=0 GRTN=55
ANALYZE,CONT LSTN=53 GRTN=44 CINT=2 DASH COLOR=100100
ANALYZE,CONT GRTN=55 CINT=5 DASH COLOR=100100
STAMP

The last ANALYZE requires some explanation. I first wrote “GRTN=55 CINT = 2”. This because the previous range is “double”: 52-55. To my surprise I got a line at 54??? After playing with the values it turned out that the starting point is the nearest multiple of CINT (and here downwards!). So asking GRTN=55 with CINT=5 starts at 55. CINT=11 is perhaps a better solution: no more lines until 66.
I suppose there is some logic in it but it took again a lot of time (too much!!) to recognize it. Next upgrade??

Greetings

Fred

[Peter Bartlett]

Fred,

Thats a nice colour fill for the script, thanks. Being fairly new to both trying learning meteorology and script writing, I have also been playing around with the following:-

TQ Index: See web site below

http://www.crh.noaa.gov/lsx/science/CON ... TQ%20Index

(T850+TD850)-1.7(T700)

CONT GRTN=10 CINT=20 DASH COLOR=200100 SMLT=4:5 STOR=5 TEMP H700 STOR=4 SSBC=3:1.7 STOR=3 SSUM=1:2 STOR=2 DEGC DWPT H850 STOR=1 TEMP H850

According to the above website, I would have expected the contour lines to have been in a much lower numerical range, so I assume that this is also a problem with negative values. Any Ideas.

[Fred]

Hello Peter

I am also a beginner in meteorology, but working for more than 30 year in IT, so the logic of scripting is not so difficult.
Indeed, the values were very high, so I changed the script, because in my opinion there was a mistake in (see below). Then I had very low values, from -10 to -40. After some more searching I saw that DEPT is already in C, do I removed DEGC. The results are now more or less in the range. Later today I try to make it in colours. I will also change the ranges in the formule (removed and changed for testing).

ANALYZE,CONT CINT=5 DASH COLOR=200100 SDIF=3:5 STOR=5 SMLC=4:1.7 STOR=4 TEMP H700 STOR=3 SSUM=1:2 STOR=2 DWPT H850 STOR=1 TEMP H850

Greetings

Fred

[Fred]

With colours

erase
ANALYZE,SDIF=3:5 STOR=5 SMLC=4:1.7 STOR=4 TEMP H700 STOR=3 SSUM=1:2 STOR=2 DWPT H850 STOR=1 TEMP H850
ANALYZE,OVER FILL COLOR=255:255:100 FILS=0 GRTN=12
ANALYZE,OVER FILL COLOR=255:014:014 FILS=0 GRTN=17
ANALYZE,CONT GRTN 12 CINT=1 DASH COLOR=200100
STAMP

[Peter Bartlett]

Fred,

Many thanks for your assistance, I'll crack this script writing soon, there again its nice learning.

[tornadoforecaster]

Guys:

Great job on these scripts! I hope you can work on others such as LI, CAPE, shear, etc. I don't know when the next DA patch is coming, so the more scripts we can make the better for now at least.

I am experimenting with a couple of scripts too, but I doubt they will work because I have no experience writing these.

Oh well!!!

RG