Weak signal
An indication of an emerging issue or an early sign of a potential change that may be meaningful in the future. A weak signal can indicate the emergence of a new phenomenon or a new side to an old one. Often coming as a surprise, it forces one to challenge present assumptions, which is why it is often difficult to notice and easy to overlook. A weak signal describes things that could have an effect in the future but are not yet significant, requiring time to mature.