Airgram and stability of air

[marcolcp]

Hi!

I am Marco from Portugal.
I dont know if it is here that I make my question but I will make it.

Is there any way to see in airgram if the air is stable and may create horizontal clouds like stratus or nimbostratus and continuous rain or the air is unstable and make vertical clouds like cumulus and cumulimbus as known as thunderstorm clouds and make rain by showers.
I know if the vertical temperature gradient is low, the air is stable, if the gradient is high, the air is unstable. Can I see it in airgram? How? Is there any parameter or index that I can measure the stability of atmosfere? I wiew in another site a lifted index.

I apreciate the answer to my question.

Greetings

Marco Pimenta