On Tuesday, my Facebook and Instagram feeds lit up with pictures of a “flat rainbow” in the area. It turns out that this was a “circumhorizontal arc”. Cliff Mass has a good blog post explaining it. “The sun’s light was refracted (bent) by ice crystals in the thin upper clouds”. Wikipedia describes it like this: “The complete halo is a huge, multi-coloured band running parallel to the horizon with its centre beneath the sun” I’ll let you read those two linked articles if you want to learn more about the science, but for now, enjoy this beautiful flat rainbow over Stevens Pass.
- Ecobee3 Data
- Adam Savage At Maker Faire