Tag: night

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Red Sky at Night, Fact or Fiction?

Sitting at my desk and watching the sunset It made me think of “red sky at night shepherds delight” which prompted the questions “Why do we say it? and “Is it true, can it predict the coming weather?”.

Sunset from my desk 🙂

The First question “why?” is fairly straightforward to answer because throughout history memorable rhymes and sayings have been used to predict the weather based on human repeated experience. These sayings are more prevalent within occupations or communities that rely on knowing the weather to bring in the harvest or shelter from a storm at sea.

So Let us begin with question two “Is it true?”…

The History

“Red sky at night, shepherd’s delight. Red sky in the morning, shepherd’s warning” Is probably one of the most famous weather related sayings, and one most people would be familiar with, probably due to the very obvious identification of a red sky. The saying first appears in the Bible in the book of Matthew. (16 v2-3,) Jesus (apparently) 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”. Throughout the generations it has stuck and transformed into the various versions we know today.

In order to understand why the developed saying of “Red sky at night, (enter a profession here) delight. Red sky in morning, (enter a profession here) warning” can predict the weather, we must understand more about weather and the colors in the sky.

NB: Usually, weather moves from west to east. In the mid-latitudes, the prevailing winds are westerlies. This means storm systems generally move in from the West.

The Colour

The colors we see in the sky are due to the rays of sunlight being split into colors of the spectrum as they pass through the atmosphere and ricochet off the water vapor and particles in the atmosphere.

The amounts of water vapor and dust particles in the atmosphere are good indicators of weather conditions.

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 color spectrum) are breaking through the atmosphere. The shorter wavelengths, such as blue, are scattered and broken up.

The Science

It would seem that the saying is most reliable when weather systems predominantly come from the west as they do in the UK and most of Europe. “Red sky at night” can often be proven true, since red sky at night means fair weather is generally headed towards you.

A red sky at sunset means high pressure is moving in from the west, so therefore the next day will usually be dry and pleasant.

“Red sky in the morning, shepherds warning” means a red sky appears due to the high-pressure weather system having already moved east meaning the good weather has passed, most likely making way for a wet and windy low-pressure system.

What is it going to be tonight?

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Navigate with the sun & stars

What’s the point? (compass pun intended).

You own a compass, GPS, sat nav etc. what’s the point in learning to navigate using other methods? When we have so much technology at our disposal why bother learning extra skills?

The answer is simple… to connect with nature. 

It’s not just using natures tools to determine what direction you are heading, it’s about understanding what you are looking at on a deeper level. Once you dive into the depths of nature it opens up a whole new way of looking at everything. 

The Sun

Sunrise and sunset

Rises in the east sets in the west. Well, sort of, mostly all of the time. The sun only rises due east and sets due west twice a year. That is on the spring and autumn equinoxes. An equinox is the time of year when day and night are the same duration. Each day the rising and setting point changes a little. 

On summer solstice, when the day is the longest (June 20th 2020) the sun will rise at 49 degrees and will set at 311 degrees. At winter solstice, when the day is its shortest (December 21st 2020) the sun will rise at 128 degrees and set at 232 degrees. So throughout the year that is a difference in rise of 79 degrees and set of 104 degrees respectively. 

Southern facing

As we are in the northern hemisphere the sun will always be in the southern half of the sky. And will be due south in the middle of the astronomical day (not midday 12:00). Looking at the compass in the picture you can see that the margin for error in winter is a lot less than in the summer in winter the sun only moves 104 degrees across the sky, in comparison to the summer where it can move 262 degrees, so adjust accordingly.

Using your watch to find south

Not totally natural but a neat trick so ill include it. If you point your hour hand of your watch at the sun, then bisect the difference between the hour hand and the 12 o’clock position and it will point you roughly south. 

Stars 

The best way to find north in the night sky is to find the location of the north star, Polaris. 
You will first need to familiarise yourself with the constellation of Ursa Major or as i know it, the Plough, it is also known as the great bear and the big dipper. Once you have found this constellation you need to find it’s two stars named Dubhe and Merak (Stars 1 and 2 in the diagram). These stars are going to be used as navigational pointers to find Polaris. Measure the distance between star 2 and star 1 and then follow an imaginary line 5 times that distance from star 1. That will take you directly to the north star which, as you quite rightly assumed, gives the location of north.