The red temperature curve show us how the temperature varies with the height in one place. To make a sounding that show the exact conditions, meteorologists use a balloon to measure the data. Remember that the soundings we use are just forecasts for the place we are interested in.
The green line show us the forecast for the dew point temperature, or for which temperature the air must have to condensate. This curve is a result of how much vapor there is in the air at different heights.
The height is shown as mbar. It is the horizontal lines. As a rule of thumb, 1000 mbar is the ground, and every 100 mbar less equals 1000 meter height. 900 mbar = 1000 meter. 800 mbar =2000 meter. 700 mbar = 3000 meter. This is correct enough for the heights we are dealing with. Higher up it starts to make a difference. The scale for height or pressure is logarithmic, and the real name of the diagram is skew-T log-P.
The flags to the right of the diagram, is the forecast for the wind direction and strenght.
The different parts of the skew-T are now defined. The next article will deal with how to read it in more details. We want to see if the air is stable or unstable, if there are danger of thunderstorms, if there will be clouds and at what height the cloudbase will be. Before you go further into this, you will benefit from going thru the articles up to this once again. If you are missing something, feel free to contact me and we will sort it out.