The ELR depends on the history of the bits of air that makes up the vertical column of air in question. The ELR will not be constant. But the little parcel of air that has just become unstable at ground level hasn't a clue what it is about to travel through. All it will do is reduce its temperature as it rises and it will always rise whenever it is warmer than the surrounding air. How far and how quickly it will rise will depend on the air that surrounds it.
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Last edited by Piltdown Man; 6th May 2017 at 07:24.
Reason: Spelling