Kia ora Aotearoa, Angus Hines (Broadcast Meteorologist) here at Metservice, and this photo here is a beautiful example of valley fog, this was taken on Cardrona ski field near Wanaka in Central South Island, obviously, the camera was well above the layer of cloud but you're looking down into those valleys. It is completely packed in with low clouds and fog. We're just going to explain a little bit about why that forms and why it is such a common phenomenon over winter.