In Pictures: Unusual clouds and red skies
People across the north-west of England woke up to unusual cloud formations against vividly coloured skies.
The Met Office said lenticular clouds combined with the sunrise to create the stunning effect.
The clouds tend to form "when air blows across a mountain range in certain circumstances" and when there is enough moisture in the air, it said.
The formations are expected to continue to grace the skies across the region over the coming days.
"It can set up a train of large standing waves in the air downstream, rather like ripples forming in a river when water flows over an obstruction," a spokesman for the Met Office said.
"With the current weather set up, we are expecting quite a bit of mountain wave activity."
Related internet links