We've all been told some proverbs about weather by an old sea wolf on our night shift, right? But did we understand what he was saying and why things happened as announced? Not necessarily, so get ready to discover the secret behind those proverbs!
1- Red sky at night, Sailor’s delight; Red sky in morning, Sailor’s warning.
First of all, everywhere on earth the sun rises on the East and sets on the West. So far so good.
Also, the meteorological systems move usually from West to East in the mid-latitudes. Easy
The reddish colour of the sky is provoked by the scattering of sunlight by suspended particles, like water vapour of clouds. Everyone is still with me?
Good, so if we combine all the previous factors: if we see a red sky in the morning, it means that the sunlight from the rising sun on the East is hitting the cloud of the West which is moving towards us. In the contrary, at night if we have a reddish sky the sunset light would be hitting the water vapor that is exiting to the East, so go for your constellation book and enjoy!
2- “A ring around the sun or moon, Means that rain will come real soon.”
To make it simple, the ring around the sun or moon is due to their light passing through ice crystals in the upper atmosphere. Those crystal usually form high clouds called cirrus which are the first that indicate an incoming low pressure.
If you want to go a bit further the ring is due to the reflection of the sunlight on the particles which act like a glass lent. Also if you see this ring, for the beginners the cloud over your head is a cirrus, yes, but for experts it's a cirrostratus.
3. “If the new moon holds the old moon in her lap, fair weather.”
Generally low pressures bring bad weather and high pressure bring sunny days.
Also, bad weather approaching brings turbulences in the air and humidity in the air (water vapor), while high pressures clear up the atmosphere.
If you can't see the dark part of the moon, this is because particles are between you and the moon. So according to the previous point, it means bad weather is approaching, while if you see the lap of the moon it means that a high pressure is on its way!