Epoch included weather alert (3)
I believe the answer is:
era
'epoch' is the definition.
(I know that epoch can be written as era)
'included weather alert' is the wordplay.
'included' indicates the answer is hidden within the clue (I've seen 'including' mean this).
'ERA' is hidden in the letters of 'weather alert'.
(Other definitions for era that I've seen before include "US equality law" , "Are involved in time span" , "Long historic period" , "Period of alteration" , "Age of importance" .)