Unraveling the Mystery: Why Severe Storms Have Green, Teal, and Blue Colors

Supercell thunderstorms are among the most awe-inspiring and powerful weather phenomena on Earth. These storms are characterized by their rotating updrafts, known as mesocyclones, which can produce severe weather conditions such as large hail, damaging winds, and even tornadoes. One of the most striking features of supercells is the occasional appearance of a green or teal color in the sky, particularly near the storm’s base. This unique coloration has fascinated both weather enthusiasts and scientists alike, prompting numerous studies to unravel the mystery behind this phenomenon.

The presence of these large water droplets is crucial to the formation of the green or teal color. Water droplets are particularly effective at absorbing red light, which is at the longer wavelength end of the visible spectrum. As sunlight enters the storm and interacts with these water droplets, a significant portion of the red light is absorbed, leaving the remaining light dominated by shorter wavelengths, which correspond to blue and green colors.

However, the absorption of red light by water droplets alone is not sufficient to explain the intense green or teal hue sometimes observed. Another critical factor is the presence of ice crystals in the upper portions of the storm, particularly in the updraft and the rear flank downdraft (RFD). The RFD is another area of descending air, located on the back side of the storm, often associated with strong winds and large hail.

Ice crystals in the upper portions of the storm can scatter the remaining blue light, further enhancing the green appearance. The combination of red light absorption by water droplets in the lower levels and blue light scattering by ice crystals in the upper levels creates the distinctive green or teal color.

The green coloration is most likely to be observed when the sun is at a low angle on the horizon, typically during the late afternoon or early evening. During this time, sunlight has to travel through more of the Earth’s atmosphere, which can further filter out red light and enhance the green appearance. Additionally, the presence of large amounts of hail in the storm can intensify the green color, as hail can also absorb and scatter light in a manner similar to water droplets and ice crystals. Most storm chasers have experienced the largest hail when storms take on green and teal colors.

It is important to note that not all supercells exhibit a green or teal color, and the absence of this coloration does not necessarily indicate a less severe storm. The appearance of the green hue depends on a delicate balance of factors, including the storm’s structure, the concentration and size of hydrometeors, and the angle of the sun.

While the green or teal color in supercells is a fascinating phenomenon, it is important to remember that it is often associated with the most severe and dangerous storms. Supercells that exhibit this coloration are likely to be producing large hail, damaging winds, and possibly even tornadoes. If you find yourself in the vicinity of a supercell with a green or teal hue, it is crucial to seek shelter immediately and follow the advice of local weather authorities.