If you've been outdoors the last couple of nights in West Michigan you've noticed two things:

1. It's COLD!

2. The night sky has been filled with light pillars.

What are light pillars and why do they form?

The National Weather Service in Grand Rapids says light pillars form best in very cold, calm conditions when a light snow is falling. The extreme low temperatures help flat hexagonal snowflakes to form lower in the sky than they normal do.

The light snow allows you to see a good distance without obstructing your view, but still creates a mirror-like effect for street lights and other outdoor lights. The lights reflect off of the snow creating the vertical streaks in the night sky.