In the evening of the last day of the summer season at Brooks Lake Lodge and Spa, northwest of Dubois, everyone was joking about how they’d gotten all four seasons in a single day. The morning sunshine had transitioned to cloudy skies and light rain by the afternoon Monday.
That’s when they noticed something special arching across the sky. It was the first time anyone had seen anything like it at Brooks Lake Lodge.
“When the rain eventually turned to snow, a rainbow appeared,” said Sara Mills, a photographer and the social media manager of Brooks Lake Lodge. “I personally have never seen anything like that, and my coworkers all reported the same thing. It was quite a phenomenon.”
Mills ran outside to get some photos of the “snowbow” before it disappeared. It was a serene scene as the colorful spectrum of light arched across the dark green landscape, slowly being covered by wet snow.
“I proceeded to Google what a rarity that is,” she said. “It was a miracle.”
The Same, But Different
“Snowbow” isn’t an official meteorological term, since it’s technically nothing special. It’s the same physical conditions coming together to produce a rainbow, except that it’s in the snow rather than the rain.
Nevertheless, snowbows aren't seen very often, making the incredible snowbow at Brooks Lake Lodge rather unique.
Rainbows are the result of refraction, internal reflection, and dispersion of light through water droplets in the air. With airborne water and the right angles of sunlight, you get a rainbow.
“The raindrops act as a prism,” said Celia Hensley, a meteorologist with the National Weather Service office in Riverton. “The sun's rays shine through a raindrop, which reflects the light back, creating a rainbow.”
That being said, there isn’t a rainbow at the end of every rainstorm. Even if the sun’s out during or after it’s rained, Hensley said it needs to be positioned correctly to create rainbows.
“The sun needs to be at an angle, rather than directly overhead," she said. "That's why you typically see rainbows more in the morning or the evening, when the sun's at the right angle."
Seeing Snowbows
Rainbows aren’t impossible during winter, but they’re much rarer. Snowflakes don't reflect nearly as well as raindrops.
“Anytime you get precipitation and the right sun angle, you're going to have a chance for some type of color,” said Cowboy State Daily meteorologist Don Day. “But when it snows, you usually have a lot of thick, low clouds that block the sun. They’re too thick for sunlight to penetrate.”
Day said snowbows are similar to fogbows, another rare phenomenon when the diffraction, rather than the reflection, of water droplets produces a ghostly-white rainbow in a chilly cloud of fog.
“On a cold morning with ice crystals hanging in the air, the water droplets can be large enough to bend light into the shape of a bow, but too small to separate the individual colors," he said. "If the sun angle is just right, you can get the bent shape of a rainbow without the color.”
Hensley added that snowflakes themselves tend to be “too cloudy” to refract sunlight like raindrops. Snowflakes freeze and condense as they fall to the ground, becoming conglomerates of crystals that aren’t reflective.
“It's hard to get the right kind of crystal and structure in the snow to get it to reflect light,” she said. “That's why they're not as common.”
The Perfect Storm
The Monday evening weather at Brooks Lake Lodge was a perfect storm for a snowbow to appear. It was a quick-moving, patchy rainstorm that transitioned to wet, heavy snow that had enough intact, clear crystals to reflect the light spectrum.
“You typically see snowbows during brief snow showers or snow squalls,” Hensley said. “Those convective-type snow showers have some rain mixed in and aren’t cloudy enough to block the sun entirely, and if it’s at the right angle, you get the reflection and see the color spectrum.”
Mills said those were the exact conditions at Brooks Lake Lodge on Monday evening. It started as rain, but as the day ended and the temperature dropped, the rain transitioned to wet snow.
“By the time we saw it, it was exclusively snowfall alongside the rainbow,” she said. “Our guests definitely had the full cowboy experience, from a bluebird day to rain and thunderstorms, and ending it all with a snowstorm and a rainbow.”
Mills should be lauded for her timely photography. Snowbows are rare enough, but getting high-quality images of them can be extremely difficult.
“That's a heck of a photo,” he said. “Snowbows are hard to catch. They happen, but it’s hard to capture the moment. It was a real treat for them.”
Mills secretly hoped the storm would pass after sunset, as she had a private photo shoot that evening. Sure enough, the clouds parted and offered a perfectly clear sky for the night.
“It was a magnificent series of events that was beneficial to both us and the guests,” she said. “It felt like a blessing at the end of our season.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
