Weather folklore has been going on for generations and was mostly started by sailors many centuries ago and possibly even from the very beginning of time. Being from the south, it’s not uncommon to hear such folklore fairly often due to the vast amount of families there who have been farmers for numerous generations. One of the most common sayings that most people have heard once or twice before is, “Red sky at night, sailor’s delight. Red sky in the morning, sailor’s warning.” So now the question is, is there any truth to the statement?
Before finding whether this is true or false, some basic atmospheric characteristics need to be checked over first. The sky gets its color from the rays of the sun being split into different colors along the electromagnetic spectrum as they pass through the atmosphere. This means that these rays ricochet off anything in the atmosphere, such as water vapor and dust particles (cloud condensation nuclei) and alter the color we interpret the sky to be. Not only do these particles potentially affect the color of the sky, the amount of them in the atmosphere can also be an indicator of the weather that could potentially occur that day. For example, excessive amounts of water vapor in the air creates an unstable environment and added with all the dust particles for the water vapor to condense upon, clouds can form. The more unstable the environment is, the faster these clouds can form, and the quicker air parcels are able to rise as buoyancy is increased through an increase in differential heating throughout the day.
We see blue skies more often because without an excess of dust particles, the ray is being reflected by the water vapor and blue wavelengths are shorter and quicker to breakdown than red wavelengths. Red skies are more often seen when there is more of an abundance of dust particles than water vapor. Dust particles are more likely to reflect the red wavelength as it is longer and tougher to breakdown than the blue wavelength with water vapor. With that being said, when there is a red sky, there is at least some evidence that there will be a humid day ahead with a greater potential for cloud coverage as the day goes on.
Normally, when the aforementioned conditions are present , typically a warm front approaching/already passed . When the red sky is seen at night, that means that there is a high-pressure system coming, meaning clear skies and decent conditions are ahead for at least the next couple days. Why is this a delight as the sun is setting? The layer at the surface at night is typically stable with the environment becoming less buoyant and more shear driven as the mixing layer that expanded during the day disintegrates. So even when the front comes through during the evening, the threat for severe weather/choppy waters is much less because the water cools off much faster than the land. Now seeing a red sky during sunrise is a completely different story. As previously stated, this typically suggests a high-pressure system is approaching. The problem with a front coming through during the day is that as the surface heats during the day, differential heating causes a heavily buoyant atmosphere where parcels can thrive and accelerate rapidly in the vertical and increase the instability. Thunderstorms will begin to form along the front (if not ahead of it as well) and cause choppy waters and potentially waterspouts if the ingredients are all there.
So, does this saying hold true? Statistically, it doesn’t seem to have been studied enough to find the correlation between the two. However, meteorologically it is very possible and would make sense for it to be true. Not all weather lore can be backed up by science, but this one seems to check all the boxes of a factual lore.
To learn more about this and other social science related topics, be sure to click www.globalweatherclimatecenter.com/social-science-topics!
©2019 Weather Forecaster Ashley Lennard