Explanation of abbreviations in Sounding Forecast (otras dudas)

[ismael.parapente]

The first to thank the entire windy team for your work.
I am a paraglider pilot in Spain and I have been using your website as a reference for my flights for a year.
I just have to interpret a line of the sounding forecats diagram; It is the horizontal gray line that we see to the left of it, accompanying the altitude / pressure and I observe that it varies according to the time of day, as well as its pressure.
I don't know how to interpret it; Who could help me to know its meaning?
Thank you, from Málaga (Spain)

[Gkikas LGPZ]

@ismael-parapente
https://community.windy.com/topic/6998/windy-offers-sounding-forecast/32
and
https://community.windy.com/topic/7059/explanation-of-abbreviations-in-sounding-forecast