zyGrib

Hello, first thank you from Spain for their great program, sorry if my English is not very good, I will try to explain as good as posible. I commented that I see a problem in creating Skew-T LogP, I attached a picture of a sounding from the NOAA Ready. You can see in the image, the bottom of the sounding begins on the surface of the uncorrected atmospheric pressure, corresponding to the height above sea level in which I find myself, if we use different pressures as 925 hPa or 950 hPa the data "LCL", "CCL", "LFC" and "EL" on surface are wrong, those pressures or even some more will help us to know at different levels how is the instability. I think that should be started for the base of the sounding with the uncorrected atmospheric pressure (936 hPa), temperature (31.7 ° C) and dew point (5.2 ° C), that are surface data from a particular location.

I hope your answer, bye bye.

Hi,

Version 6.0.1 solves this problem (very partially): you can change the base level for convective calculation,
but only in a limited list of levels.

The main difficulty: there are computed theorical soundings, not true ones, with an artificial surface level of 1000 hPa.
In the very large majority of cases, it is a good approximation, but it is poorly suited to mountainous regions.

There is a concept of surface pressure in data from NOAA. It could serve as a base level,
but this does not solve the problem in mountainous regions because it is only on average level on the mesh.

If you have better ideas...

Hi, thanks for your answer, you are right about the estimate of the height of the NOAA, I live in Valdepeñas (Spain) and the height is 705 meters and the NOAA estimate is 728 meters. One option would be to put oneself the data of surface temperature, dew point temperature and atmospheric pressure, as a weather station which I have a Davis Vantage Pro2 or use different data to see what can happen with that data. There is a post which talks about the Lifted Index (LI), that I use it a lot, it is a fact that is usually provided in the sounding, you just have to control temperature inversions at higher levels, it helps CAPE to know the level of instability in the atmosphere. I've done some courses about meteorology: https://www.meted.ucar.edu/index_es.php , a course called "Domain skew T log p" https://www.meted.ucar.edu/training_module.php?id=225 , is very good to know how to use a sounding, has an application called "Interactive Diagram" that works in Flash and allows you to represent a sounding with all its data from surface data (RH, virtual temperature, Theta, Theta-E, etc. ..), data level (LCL, CCL, LFC, LE, etc. ..), levels of thunderstorms (convective temperature, LI, TT, SWEAT, etc. ..), and other indices (CAPE, CIN, layer thickness "Thickness 1000-500", etc. ..). I think if you could do the sounding in that way it would be very good, and even to put the data in a meteotable with the possibility of saving. Finally I ask for a little help, I exported the data from NOAA to Excel and I do some calculations like K index, SWEAT, TT, LCL, etc. .., but other data like CCL, LFC, EL, Thickness 100-500 etc…, I haven’t got the formulas to do these calculations, and I have not found a way to get it, I would like if you could tell me where I can I find those formulas, I thanks you.

Hi, this is a photograph of the radiosonde program.