What’s an atmospheric river? A pineapple express? AP explains the weather phenomenon

Atmospheric rivers are long and relatively narrow bands of water vapor that form over an ocean. Some get the nickname Pineapple Express, for a reason.

​Atmospheric rivers are long and relatively narrow bands of water vapor that form over an ocean. Some get the nickname Pineapple Express, for a reason.   Atmospheric rivers are long and relatively narrow bands of water vapor that form over an ocean. Some get the nickname Pineapple Express, for a reason.