adverb
Literary or somewhat formal adverb indicating that something happened just as anticipated. In everyday speech, やっぱり or 案の定 are more common.
果然、彼は約束の時間に現れなかった。
Sure enough, he didn't show up at the promised time.
天気予報の通り、果然午後から雨が降り出した。
As expected from the weather forecast, it started raining in the afternoon.