Rare 'rainbow' clouds spotted in skies over Sunderland

Rare clouds formed beautiful rainbow patterns in the skies above Sunderland this morning, and Echo readers captured the magic on their phones.

The iridescent nacreous clouds form high in the atmosphere, and a more common in polar regions.

They are a rarity in the UK because of the very particular conditions needed.

The form in very cold conditions over polar regions and within the stratosphere, around 12-19 miles (19-31km) high.

Cold polar air is locked in place by high winds in the atmosphere, known as the polar vortex. But when this weakens, the cold air shifts slightly into the skies high above the UK.

When the air is around -80C, it forms ice crystals which break up sunlight into its component colours, creating the mother-of-pearl effect seen by those lucky enough to spot it this morning.