Stunning Light Pillars Light Up A Cold Vermont Night

The National Weather Service office in South Burlington
Friday posted this incredible photo of light pillars
at Jay Peak Resort. Cold, calm weather helps
create this relatively rare phenomenon.

 The National Weather Service office in South Burlington on Friday posted a spectacular photo of light pillars before dawn Friday at the Jay Peak Resort.   

As you can see in the photo, street and parking lights, outdoor security lights and such formed narrow, towering beams of light that looked like a strange impressionist painting.  It looked like some sort of freaky laser light show.

So why did ordinary outdoor lights go haywire on a chilly December pre-dawn?

The lights were fine and working as designed. It turns out a certain type of ice crystal that forms on very cold nights created this relatively rare phenomenon. 

 According to Science ABC:

"These plates of ice crystals orient themselves hexagonally as they drift down through the atmosphere. Their collective surfaces act like a giant mirror that reflects the light falling on them. The light being reflected will extend to a certain distance both above and below the light source. The denser and larger the ice crystals, the more pronounced this effect becomes.

The angle of the ice crystal surfaces will deviate a few degrees from the horizontal orientation, which causes the light pillar, as it elongates the reflection of light. Thus, these phenomena usually appear as columns of lights to an observer."

We get lots of cold nights in Vermont during the winter. As you've guessed, this type of cool light display can only happen under certain conditions. First of all, winds need to be pretty much calm. Wind would disrupt the reflection of light. 

Usually, cold air is pretty dry, but it does contain some moisture, certainly enough for the ice crystals to form. To help with the moisture supply, there was a temperature inversion over Vermont early Friday. 

The inversion, in which a layer of warm air rests atop cold, dense air near the surface, forms a lid.  Moisture from the ground, exhaust from chimneys and cars, and evaporation from rivers and streams probably added to the moisture content of the air. 

Light pillars were also seen elsewhere in Vermont Thursday night and Friday morning. Some spectacular ones were spotted in Barre, for instance. 

Most winter nights don't feature light pillars. But if you want to try hunting then down, they're most likely well after sunset, and often in the pre-dawn hours when winds are lightest.