You most likely know the old saying. “Red sky at night, hiker’s delight. Red sky in morning, hiker’s warning.” Ok, maybe not that “exact” version. Chad’s mom used to tell him that old adage when he was growing up. We’re not sure if she knew any actual science behind it though. It’s just one of those proverbs people pick up along the way. The reaquestion though, is there any truth to it? Could it actually help you while you are out in the backcountry with no cell service? Well, let’s dig into it and find out.
You crawl out of your tent, at five in the morning, to watch the sunrise. Staggering around like a modern Frankenstein, grunting and chucking things around until you find your coffee thermos. With one eye open, you look out over the mountains and see a sky full of pink and red radiance. You think to yourself, damn that’s beautiful. Then the next thing you know, the old proverb “red sky in morning” starts floating through your caffeine deprived noggin. You realize you’re on top of a mountain, in the middle of the backcountry, with no cell service. Are you about to get caught in a torrential downpour? You might also realize that your cranium is the highest point, on the highest mountain, in the seeable region. They say getting struck by lightning is 1:100,000 or something like that. Now, we’re going to be honest here. We’re not great at math, or odds for that matter. But, what we do know though is that we aren’t feeling great about those odds. Given your current location, you’re moving up the odds chart in a hurry. So if there is any truth to the proverb, we’re going to take a good look at it and possibly head down to lower elevation.
So, toss on your chemistry goggles. Let’s get nerdy and dive into the science behind the theory.
You know when you’re watching the news, and they cut to the weather person? They are always standing in front of a map that is covered in a bunch of “L’s” and “H’s”. Those are low and high pressure areas. The thing is, you can’t have one without the other. It’s like the phrase “with every action is a reaction”. If you see a “H” there will always be a “L” on both sides of it.
How do they work?
Low pressure systems are associated with bad weather. Basically the air fills up the low layer and then causes upward motion which creates clouds and precipitation.
High pressure systems, on the other hand, are associated with good weather. High pressure creates a downward motion that breaks up and suppresses any cloud formations.
Still following us so far? Here’s where the colors come into play.
Low pressure systems are cloudy and clean.
High pressure systems are cloud free but dirty. Pollen, dust, soot, and other particles get trapped in the atmosphere here.
Remember in grade school when you learned about the colors of the rainbow? Yeah, we know, you thought you’d never use that information again. The cliff notes are that we see different colors based on different wavelengths of radiation.
- Blues are the short wavelengths
- Reds are long wavelengths
The sun’s light beams into earth’s atmosphere, and it gets scattered by air molecules. Air molecules scatter the light into short wavelengths. Remember what color is a short wavelength? Blue. Yep, that is the reason why the sky is blue.
When the atmosphere is dirty, like in a high pressure system, the aerosols (dust, pollen, soot) scatter the light into longer wavelengths. With longer wavelengths you will see red and orange.
So how does this tie into the old weather adage?
Lets go back to your Frankenstein moment on top of the mountain. You are watching the sunrise in the East, and it’s red. Red skies indicate High Pressure areas. Remember what lies right next to High Pressure? Low Pressure. Weather generally follows the jet stream from West to East, which means the High Pressure (good weather) is moving away from you. The Low Pressure (bad weather) should be rolling in right behind it. Hiker take warning.
On the other side of the boot, you are watching a jaw dropping brilliantly red sunset. Since the sun is setting in the west, and it’s red (high pressure), then good weather will be coming in your direction. The jet stream will be bringing it from the west towards you. Hiker’s delight.
If you happen to live in a region where you have an east to west jet stream, then the adage would just be reversed.
Hope you enjoyed and found that useful. Have any feedback? Let us know in the comments below.