NOTE: action of the verb occurs before a new state or event.
The asteroid heralded a new era of life.
Darkened skies herald rain.
Snowmelt heralds Spring.
WordNet 3.0 Sense Numbers: 1
NOTE: action of the verb occurs while a new state or event is coming to be or already evident.
The critics heralded the pianist as a new master.
They all heralded the knight's entrance.
Flowers herald Spring.
Her screams heralded the arrival of their newborn child.
WordNet 3.0 Sense Numbers: 2, 3