Too much pressure above the southern locomotive (10)
I believe the answer is:
overstrain
'too much pressure' is the definition.
The answer and definition can be both types of natural phenomena as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'above the southern locomotive' is the wordplay.
'above' becomes 'over' (I've seen this before).
'the southern' becomes 's' (abbreviation).
'locomotive' becomes 'train' (I've seen this before).
'over'+'s'+'train'='OVERSTRAIN'
Can you help me to learn more?
(Other definitions for overstrain that I've seen before include "too much exercise may produce this" , "Tax" .)