Rare and beautiful 'mother of pearl' clouds

Large parts of the UK have seen some very rare clouds that looks like a sheet of rainbow across the skies over the last few days. Lots of people thought they were rainbows in the sky or the northern lights.

They are actually a rare cloud called nacreous clouds or polar stratospheric clouds, they are also known as mother of pearl due to their iridescent appearance.

They occur in the winter polar stratosphere (the atmosphere above the one our weather occurs) over 50,000 ft high,15–25KM. They are usually spotted just before dawn or just after dusk, when the sun is between 1 and 6 degrees below the horizon, meaning these clouds receive sunlight from below the horizon and reflect it to the ground.

The stratosphere is very dry-unlike the troposphere (where out weather happens) and it rarely allows clouds to form, so keep your eyes peeled and you may spot more of them over the coming days.

Storm Gertrude: What you need to know!

- The Met Office has issued an amber warning as gusts of 90mph and heavy rain head for the UK's Friday morning rush hour.

- A yellow warning for snow and ice has also been issued for the majority of Scotland and parts of northern England, which are likely to hit later in the day.

- Take care: gusts between 60mph and 80mph, especially near coastal areas, and heavy rain threaten to lash these areas between 3am and 10am on Friday and drenching areas with heavy rain.

- Strong winds are also headed for Northern Ireland as well as in England, Scotland and in the Northern Isles (could be up to 90mph!).

- Take care: Big waves, damage to power cables and structures is expected along with ferry and rail cancellations.

- Plan ahead: Lots of bridges and roads have already been closed.

- Gertrude has been named so the public are more aware of these storms over a 'normal' winter storm, and able to keep themselves, their property and businesses safe.