A red sky in the morning...

There certainly was a red sky this morning, but it did not take long to clear, leaving a cold bright start to the day.

However, is there any truth in the old adage ‘Red sky in the morning is a shepherd’s/sailor’s warning’ ?

It seems there might be, indeed, Shakespeare certainly heard of it and made good use of it in his writing. He said something similar in his poem, Venus and Adonis: “Like a red morn that ever yet betokened, Wreck to the seaman, tempest to the field, Sorrow to the shepherds, woe unto the birds, Gusts and foul flaws to herdmen and to herds.”

Meanwhile, in the Bible, according to the Gospel Matthew 16: 2-3, Jesus said: “When in evening, ye say, it will be fair weather: For the sky is red. And in the morning, it will be foul weather today; for the sky is red and lowering.”

Weather lore has been around since people needed to predict the weather and plan their activities. Sailors and farmers relied on it to navigate ships and plant crops.

But can weather lore truly predict the weather or seasons? it seems there is some truth in the old tale...

Usually, weather moves from west to east, blown by the westerly trade winds. This means storm systems generally move in from the West.

The colours we see in the sky are due to the rays of sunlight being split into colours of the spectrum as they pass through the atmosphere and ricochet off the water vapour and particles in the atmosphere. The amounts of water vapour and dust particles in the atmosphere are good indicators of weather conditions. They also determine which colours we will see in the sky.

During sunrise and sunset the sun is low in the sky, and it transmits light through the thickest part of the atmosphere. A red sky suggests an atmosphere loaded with dust and moisture particles. We see the red, because red wavelengths (the longest in the colour spectrum) are breaking through the atmosphere. The shorter wavelengths, such as blue, are scattered and broken up.

So, Red sky at night, shepherd’s delight: When we see a red sky at night, this means that the setting sun is sending its light through a high concentration of dust particles. This usually indicates high pressure and stable air coming in from the west. Basically good weather will follow.

And... Red sky in morning, shepherd’s warning. A red sunrise reflects the dust particles of a system that has just passed from the west. This indicates that a storm system may be moving to the east. If the morning sky is a deep fiery red, it means a high water content in the atmosphere. So, rain is on its way.

Have you got your brolly at the ready?

Thank you to Finola Faller for her photograph of this morning’s beautiful herring sky.