The sky can take on a variety of colors during a tornado, depending on the time of day, the amount of debris picked up by the tornado, and other weather conditions at the time. Some common colors seen in tornado skies include grayish-green, brown, yellow, and even red or purple. The exact cause of these colorful skies has long fascinated meteorologists and storm chasers alike. In this article, we’ll explore some of the main factors that influence the color of the sky during a tornado.
Time of Day Effects
One of the biggest influencers is simply the time of day of the tornado. During daytime tornadoes, the sky is usually dark gray, greenish, or brownish in color. Debris kicked up by the tornado winds blocks sunlight and causes the characteristic dark color. At night, the tornado sky appears darker black because there is no sunlight to filter through the debris clouds.
Daytime tornado skies are darker than typical stormy skies because tornadoes stir up more debris than average thunderstorms. Their powerful winds lift dirt and vegetation from the ground, which mixes with water vapor in the funnel cloud to create the distinctive dark tones. The stronger the tornado, the more debris it carries, leading to darker skies. Weaker tornadoes may only show slightly darkened cloud bases.
Debris Effects
The specific color of a tornado sky depends largely on the composition of debris picked up by the tornado’s winds. Soil, dust, vegetation, construction materials, and other particles swirl around the funnel, tinting the funnel cloud based on their color.
Tornadoes over dry dirt or grasslands tend to take on brown and tan hues as dirt is stirred into the vortex. Over forests and farmland, greenish debris from plants and trees creates an eerie green sky. Grayish and dark brown colors result when tornadoes move through urban areas, picking up concrete, asphalt, roofing tiles, wood, and other structural debris. The more varied the debris, the murkier the mixed color often appears.
Weather Effects
Existing weather conditions at the time of tornado also influence the sky color. Tornadoes occurring under already overcast skies will appear darker than those under sunnier skies. Clouds block sunlight and cast an overall darker tone across the landscape even before the tornado forms.
Thick storm clouds surrounding the tornado funnel can also lead to darker gray-green tones. Low cloud bases characteristic of severe thunderstorms bring the darker debris clouds closer to the ground, intensifying their color.
Additionally, areas with high humidity see darker tornado skies as the moisture intensifies the available sunlight. Dry air usually means brighter tornado skies as sunlight scatters more sharply among the debris particles.
Time Progression
Tornado skies tend to darken as the tornado intensifies and picks up more debris during its life cycle. At tornado onset, the funnel may exhibit lighter brown shades. As it tracks across land and damages more structures, it gathers darker, murkier debris and the sky takes on darker green-brown hues. At dissipation, the tornado sky lightens again as heavier debris drops out and lighter particles remain suspended.
This progression can happen over very short timeframes. Some tornadoes cycle between more intense phases with darker skies and weaker phases with lighter skies multiple times as they travel along their path. Wall clouds sometimes exhibit greenish tones that shift to brownish-black when the funnel forms underneath. The tornado sky color provides visual cues about the tornado’s current intensity.
Smoke Effects
Fires sometimes started by the tornado can contribute unique color effects. Smoke from burning vegetation or structures mixes into the vortex, producing crimson, brown, or black plumes. Scattered fires across a wide area engulf the tornado in vivid red-orange hues under daylight conditions. At night, the fires illuminate the smoke, creating eerie nighttime tornado colors.
Photographs of fire tornadoes showcase their dramatic reddish-orange color. The fire’s heat lifts the smoke high into the funnel while the strong winds shape the smoke into the classic tornado profile. Even without fire, strong updrafts in the tornado can draw smoke high into the vortex from distant sources.
Lighting Effects
Tornado color also depends on the available light illuminating it. Tornadoes at dawn or dusk often exhibit more intense orange, red, or pink hues as the sunlight streams through the debris clouds at a low angle. Low sunlight creates more dramatic, colored lighting visible from multiple directions.
Positioning of the tornado relative to the observer also changes its color. When backlit by the sun, it may appear darker. When front-lit, sunlight can make it glow golden brown. Side-lighting produces more neutral gray tones. Photographs capture the view from the photographer’s angle, which may show different tornado colors than observers would see in person.
Dust Storm Mixing
In dry areas, tornadoes can mix with dust storms, creating darker brown-orange skies. The storm’s gust front lifts massive dust clouds from the dry terrain. As the tornado forms, it ingest the dust, concentrating it into dense brown walls. The dust overwhelms other debris colors, creating a warm orange glow.
This occurs most famously in Mexico’s Tornado Alley where dry conditions lead to frequent tornadoes and dust storms. The region’s darker tornadoes lead to its “black tornado” nickname. Dry parts of Texas and Oklahoma also see tornadoes mixing with reddish-brown dust clouds, creating chocolate-milk colored skies.
Conclusion
In summary, tornado skies take on a wide spectrum of colors due to the complex interactions of time of day, debris composition, cloud conditions, humidity, smoke, lighting angle, and other weather factors. The colors provide valuable visual clues about tornado intensity, the types of debris present, and the amount of damage occurring along its path. While fascinating to observe, dark-colored tornadoes also serve as an important reminder to take safety precautions in the presence of these dangerously beautiful storms.