A green sky usually signifies that a storm is severe, but not necessarily that a tornado is coming. According to the provided reference, the green color in a storm sky indicates a severe storm. The color occurs when water droplets in the storm absorb red sunlight and radiate green frequencies. Here's a breakdown:
Understanding the Green Sky Phenomenon
The green sky phenomenon associated with storms has specific characteristics:
- Severe Storm Indicator: The primary meaning of a green sky is that the storm overhead is likely severe.
- Not a Tornado Warning: It's important to note that a green sky does not automatically mean a tornado is imminent.
- Light Interaction: The green hue results from the way sunlight interacts with the water droplets and ice crystals within the storm clouds. Specifically, larger water droplets can scatter light, and when red sunlight is filtered through these droplets, it can result in a green appearance.
Why Does the Sky Turn Green?
The specific process that leads to a green sky involves light scattering:
- Water Droplets and Ice: Severe storms contain a high concentration of water droplets and ice particles.
- Sunlight Absorption: These water droplets and ice particles absorb and scatter sunlight.
- Red Light Filtering: When the sun is at a low angle (often in the late afternoon or early evening, when severe storms are common), the red and yellow wavelengths of sunlight are scattered away, leaving mostly blue light.
- Green Appearance: The blue light scatters within the cloud, and when combined with the red light that passes through, it can create a green appearance.
- Severe Weather Conditions: The presence of a green sky indicates the storm contains a significant amount of moisture and is likely to produce large hail, strong winds, and potentially heavy rainfall.
Green Skies: What to Do
If you observe a green sky, it is wise to take precautions:
- Monitor Weather Reports: Stay updated with the latest weather forecasts and warnings from reliable sources.
- Seek Shelter: If severe weather is predicted or a warning has been issued for your area, seek shelter immediately.
- Be Prepared: Have a plan in place for severe weather events, including a designated safe place and an emergency kit.
