Red sky at night shepherds delight?

[Homer55]

Whats the scientific explantion for this? if there is one?

[Quizmonster]

Click here for an excellent previous answer.

[heathfield]

It can be very dependent on locality. Where I am, if snow and an east or southeast wind is forecast, it's 'grey sky in the morning = get your wellies out', and shepherds will worry about their sheep!