In a warm front, a mass of relatively warm air pushes against a block of cooler air and is forced to flow up over it.

BBC: Turbulence ahead: Flight heads into storm's heart

Expect your adrenaline levels to rocket and, in the warm, thin air, you will realise that cowering in front of an oncoming silverback is not something you could ever get used to.

BBC: Gorillas in the mix in Uganda