Question

Why are upper atmosphere measurements so important for weather forecasting?

Answer 1

We need to know the instability of the whole atmosphere to properly forecast.

Explanation:

Just because the air on the surface is unstable or stable it is not a good way of forecasting what will happen because the situation aloft can be totally different. That is why we analyze the atmosphere at many different levels and why we have upper air soundings that give us data all the way up in the atmosphere.