SNOWSHOE, WV. – It’s something seen more commonly in northern latitudes, not this far south. Light pillars are a neat optical phenomenon that can be caused by either natural or artificial light. In the case of Snowshoe Mountain Resort earlier this week, it was artificial street lights that were partially responsible.
The other part responsible for this phenomenon — the Arctic air. Temperatures at Snowshoe during the time of the light pillars were around 5°F, with light snow falling. At that temperature, snow has hardly any water in it. It’s mainly just ice crystals.
The flatness and the shape of these ice crystals allow them to act as mirrors. When the light shines threw them, they bend that light in different ways and can then form what appears to be a vertical column (from our eye’s perspective).
We see this happen sometimes around sunrise or sunset when ice crystals in high-level clouds (often 30,000 feet or higher) behave in a similar fashion. However, it’s quite rare for these light pillars to happen at night this far south because that kind of cold air seldom gets this close to the surface.
When it does, it’s even more uncommon for there to be any moisture or ice to play with the light a little.