UNION COUNTY — Thunderstorms are a common occurrence in summer, but Tuesday’s thunderstorms left in their wake something that’s not so common: a double rainbow.
Lauren Visin, a student meteorologist with the National Weather Service in Greer, said that Tuesday’s thunderstorms were not the result of a true storm system but the combination of a high pressure “Bermuda High” that is pulling moisture into the Upstate from the Atlantic Ocean and the Gulf of Mexico. Visin said this produced the very warm and muggy environment that provided the fuel for thunderstorms when any energy entered the area. She said that happened late Tuesday afternoon when a “short wave,” which she described as “a piece of energy” entered the atmosphere.
It was in the wake of the thunderstorms spawned by this combination that many Union County residents saw the rare phenomenon of a double rainbow.
“All rainbows have the potential to form double or triple rainbows,” Visin said. “It just depends on how the light hits the water droplets. The water droplets serve as a prism and the light hits them. When the light reflects off the prism you see the first rainbow.
“The second rainbow could be considered more of a shadow of the first rainbow rather than a true second rainbow,” she said. “Again, you have the light hitting the prism and, being reflected off of it, strikes other droplets just right and that’s when you get the second rainbow.”
Visin said that another factor in whether a person sees a rainbow or a double or even triple rainbow is their point of view.
“It all depends on your viewpoint and because of that I’m pretty certain not everyone in Union saw a double rainbow,” Visin said. “It’s very rare that you get just the right angle, but when you do it is pretty spectacular.”
Visin said that the conditions that produced the thunderstorms were still in place Wednesday though not as strong as they were Tuesday. She said it was quite likely that the area would see more storms later in the day and throughout the rest of the week.
Editor Charles Warner can be reached at 864-427-1234, ext. 14, or by email at firstname.lastname@example.org.