A red stormy sky is a phenomenon that occurs when dust, smoke or other dry particles are suspended in the air, causing the sky to take on a reddish hue. This often happens in the hours before a storm, leading to the old saying “red sky at night, sailor’s delight; red sky in morning, sailor take warning”. The red skies are caused by the scattering of sunlight through the atmosphere under particular conditions. Understanding what causes red stormy skies can help predict upcoming weather and stay safe.
What Causes Red Stormy Skies?
There are a few key factors that contribute to red stormy skies:
Particles in the air – Dust, smoke, fine sand or other dry particulates high up in the atmosphere cause the red color. These particles scatter and reflect red wavelengths of sunlight, causing the vivid red tones. Particles from dust storms, wildfire smoke, volcanic eruptions or pollution usually cause the red skies.
Position of sun – The red color is intensified when the sun is low on the horizon, near sunrise or sunset. Sunlight travels through more atmosphere at those times, increasing the scattering effect of the particles.
High pressure system – Red skies often precede stormy weather associated with an approaching low pressure system. The dry, sinking air from high pressure above pushes particles downward, trapping them under moist air below and causing the vivid red hues.
Dry air – Very dry air helps keep the particles suspended for longer to maximize the red sky effect. Humid, moist air tends to cleanse particles from the atmosphere.
So in summary, having lots of dry particulates high up in very dry air, with sunlight shining through at a low angle near sunrise or sunset, provides the perfect conditions for seeing intensely red skies overhead.
When are Red Skies Most Likely?
Red stormy skies are most common under the following circumstances:
- During drought conditions that create a lot of dust in the air
- After large wildfires when smoke is high in the atmosphere
- Downwind of volcanic eruptions that eject tons of particulates
- Ahead of approaching storms that trap dust under high pressure
- Near large deserts like the Sahara where sand gets lofted upwards
- In areas with high air pollution levels
- Around sunrise/sunset when sunlight streams through the atmosphere at an angle
Places like the dry Southwest United States, the Sahara region of Africa and industrialized regions of Asia with poor air quality see red stormy skies relatively frequently under the right weather conditions. But they can happen anywhere there are lots of particles in the air with a storm system approaching.
Red Sky at Night or Morning?
The time of day of the red sky also holds clues about upcoming weather, according to the old saying:
“Red sky at night, sailor’s delight. Red sky in morning, sailor take warning.”
This saying refers to:
- Red evening skies mean high pressure is moving in and the weather should be good.
- Morning red skies indicate high pressure is leaving and an approaching low pressure storm system.
The basic explanation is:
- Red evening skies – High pressure air sinks, pushing particulates down with sinking air. This traps particles underneath moist air flowing in from low pressures, causing vibrant red hues with sunlight from the west. The clearing high pressure brings good weather.
- Morning red skies – Those sinking high pressure conditions have passed overnight, allowing the moisture to rise up and particulates to be washed out. The red color is from high level particles from the departed high pressure. It indicates an approaching low pressure storm.
So red skies at night are a good sign, while morning red skies warn of rain or stormy weather on the horizon. This rhyme originated centuries ago and is a useful rule of thumb for interpreting red sky omens.
Are Red Skies a Guaranteed Storm Predictor?
While a red stormy sky is a good general indicator that an area may soon experience rain or storms, it does not guarantee poor weather. There are times when the red sky conditions just mean lots of particles in the stable air, with no storms actually developing.
Some key points:
- Red sky alone does not always mean rain is imminent. Other weather data is needed.
- Sudden formation or intensifying of red in the evening has the most correlation with approaching storms overnight.
- Morning red skies indicate high likelihood of wet weather within 12-24 hours.
- Red skies in both morning and evening increase the confidence of stormy weather arriving.
- The brighter and deeper the red color, the higher the chances of strong weather.
So while a red sky can serve as a helpful general indicator for mariners, farmers and meteorologists to interpret trends, complementary data from weather radar, satellite, models and station observations is needed to forecast actual storm timing and intensity. Not all red skies produce immediate storms.
Other Weather Clues in Red Skies
In addition to the general red sky storm predictor, there are some other weather clues that can be taken from observing reds stormy skies:
Wind speed – High winds appear to precede the most intense red skies, as strong gusts loft more dust and particulates high into the air. Calm winds typically mean less vivid red colors.
Clouds – Red skies reflected onto cloud bottoms indicate very high levels of particulates that could mean more intense storms. Cloud-free areas allow better sunlight penetration.
Visibility – Poor visibility from surface haze correlates to higher concentration of particles causing the red sky above it. Good visibility tends to accompany lighter red colors.
Sunset color – More intense orange and yellow hues at sunset generally indicate more impending particle cleansing and clearing weather ahead.
So analyzing winds, clouds, visibility and the gradations of red to orange and yellow can provide additional insights into the upcoming weather beyond just the presence of a red sky alone.
Photographing Red Stormy Skies
The stunning red colors filling the sky make for dramatic photography opportunities. Here are some tips for capturing eye-catching photos of red stormy skies:
- Use a DSLR or mirrorless camera with manual controls for the best results.
- Shoot around sunrise or sunset when the light angles enhance the red tones.
- Include foreground silhouettes of people, structures or natural features to add depth.
- Try long exposure times of several seconds to smooth out clouds.
- Experiment with wide angle and telephoto lenses for different effects.
- Use RAW format for higher quality and adjusting white balance.
- Play with filters like polarizing or neutral density to darken blues and enhance contrast.
- Change composition to highlight colors and textures in different parts of the sky.
Patience for the perfect conditions and some practice will help capture eye-catching photos of the temporary spectacle of red stormy skies.
Safety Tips for Red Sky Storms
While aesthetically pleasing, red stormy skies can portend hazardous weather approaching. Here are some tips for staying safe:
- Seek shelter when storms approach, as red sky winds can be powerful.
- Beware reduced visibility in dust storms, smoke and haze that causes red skies.
- Avoid being caught outside if lightning coincides with red skies.
- Reduce time outdoors around sunrise/sunset when intense red light can mean more UV exposure.
- Check updated forecasts and weather alerts for changing conditions.
- Ensure emergency supplies are stocked and ready like flashlights, batteries and water.
- Postpone plans like boating or climbing that could be risky with impending storms.
- Keep air conditioning filters clean to reduce indoor particles aggravating allergies and asthma.
Following safety common sense, while appreciating the beauty of a rare red sky, allows enjoying the spectacle while staying protected.
Historical Red Sky Storms
Some of the most vivid red stormy skies recorded include:
The California Red Skies of 2020 – Massive wildfires cluttered the air with smoke particles that created blood red skies across California in September 2020, heightening the apocalyptic feel from the rampant fires. The extremely dry air kept the smoke aloft and thickened by high pressure contributed to the surreal scenes.
The Dust Bowl Red Skies – The dry, windy conditions during the 1930s Dust Bowl over central North America led to many severe dust storms. The dense dust blown into high altitudes created blood red skies and intensely colorful sunsets documented in photographs from the era.
Krakatoa Eruption Sky of 1883 – One of the most vivid red sky events came after the enormous Krakatoa volcanic eruption in Indonesia in 1883. Ash and gases were propelled over 50 miles into the stratosphere, creating stunning red twilights and afterglows that persisted for years worldwide and were visible as far as France.
New England Red Sky of 1950 – In September 1950, strong winds lofted massive amounts of dust from the Southern Plains and Canada into the air over New England. There were reports of lavender suns and crimson moon glows from the abundance of particles.
These cases illustrate the range of extreme red sky events seen throughout history that arise from different particle sources. While less intense, today’s red skies still provide useful weather clues.
Conclusion
Red stormy skies are a fascinating meteorological phenomenon caused by the scattering of sunlight through dry particulates suspended high in the atmosphere. The red colors can range from faint blushes to apocalyptic shades of crimson, signaling stable air or an approaching low pressure storm. While not a guaranteed predictor, interpreting red skies using the rhyme “red at night, sailor’s delight; red in the morning, sailor take warning” provides useful weather insight. Observing accompanying conditions like winds, clouds and visibility can add confidence in the forecast. With care and preparation, the splendor of red stormy skies can be enjoyed while staying safe from the potential hazards they may presage. The next time you see a red sky overhead, read it carefully and determine what kind of weather may be on the way!
