https://weather.com/en-GB/unitedkingdom/weather/video/stunning-rare-nacreous-clouds-over-the-uk (https://weather.com/en-GB/unitedkingdom/weather/video/stunning-rare-nacreous-clouds-over-the-uk)
I have never seen this before................ ???
I have seen these on very cold days but they are very rare.
They're over northern Europe now because of a -80-100ÂșC stream of air 18km above our heads, coming from the north pole. I haven't seen them though, glued to my computer too much ::)