scenario

future, likely, possible

In a possible scenario, the company could merge with its competitor next year.

unlikely

optimistic

doomsday, nightmare, pessimistic, worst, worst-case

dramatic

alternative

consider, construct, imagine

describe, paint

Climate scientists describe a scenario where rising sea levels could flood major cities by 2100.

enact, play out

During the emergency drill, the team had to enact several difficult scenarios to prepare for a crisis.

unfold

in a/the ~

In that scenario, we would have needed to leave much earlier to catch the train.

under a/the ~

If the weather gets worse, under that scenario we'll have to cancel the outdoor wedding.