a sign of
変な空だが天気の変の前触れだ。
The strange-looking sky is a sign that the weather is about to change.
鶏の鳴き声は夜明けの前触れです。
The crowing of a rooster heralds the dawn.
もうひとつは死の前触れ…
The other one is an omen of death…
— RRR (2022)
風向きの変は天気の変の前触れだ。
A change in wind direction is a sign of changing weather.
ツバメは夏の前触れだ。
Swallows herald the arrival of summer.
彼は何の前触れもなくやめた。
He quit without any warning.