Supplies forecasts for a long time in newspapers (8)
I believe the answer is:
presages
'supplies forecasts' is the definition.
'presages' can be an answer for 'forecasts' (I've seen this before). I'm unsure of the 'supplies' bit.
'long time in newspapers' is the wordplay.
'long time' becomes 'age' (an age is a period of time).
'in' is an insertion indicator.
'newspapers' becomes 'press' (the press is the newspaper industry).
'age' inserted within 'press' is 'PRESAGES'.
'for a' acts as a link.
Can you help me to learn more?
(Other definitions for presages that I've seen before include "Augurs, bodes" , "Foreshadows, is advance sign of" , "Forecasts" , "Foreshadows in press age" .)