1 approaching, nearing, impending, imminent, coming, (close) at hand, upcoming; near or close (by), (near or close) at hand, in the offing, on the horizon, Colloq Brit on the cards, US in the cards:
The forthcoming tax increase will affect everyone. A new regulation is forthcoming.
2 awaited, expected, anticipated, looked-for, watched for, prospective, foreseen:
The forthcoming payment will be be a little late.
3 outgoing, friendly, amiable, affable, sociable, accessible, expansive, chatty, talkative, communicative, informative, open, free, revealing, unreserved:
Barry was most forthcoming when questioned about his finances.