Whisperward

Whisperward can be cast on any single item, portal, or closure (such as a book, door, or lid). It may ward up to a 30-foot radius.

The character keys the ward to become activated (like a Magic Mouth spell) under specific conditions--such as when a certain individual enters the area or opens the warded closure. When the ward is triggered, a soft whispering breeze blows across the caster's face. The caster must stay within 1 mile per experience level of the ward to receive the warning.

[Complete Druid's Handbook]

Druidic

Sphere: Guardian, Weather
(Alteration)
Level: 1

Range: Touch
Components: V, S, M
Duration: Permanent until triggered
Casting Time: 4
Area of Effect: 1 item
Saving Throw: None

Material Components: the druid's holy symbol