Below zero inside so like stormy weather (10)
I believe the answer is:
thunderous
'stormy weather' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I can't see?
'below zero inside so like' is the wordplay.
'below' becomes 'under' (synonyms).
'zero' becomes 'O' (O resembles 0).
'inside' is an insertion indicator.
'so like' becomes 'thus' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'under'+'o'='undero'
'undero' going into 'thus' is 'THUNDEROUS'.
Can you help me to learn more?
(Other definitions for thunderous that I've seen before include "Loud and rumbling" , "Deafening" .)