Light pillars visible overnight; Lake Superior ice highest in 4 years
Did you see them? Our light overnight snowfall was perfect for reflecting light from below. Light pillars were reported around the region.
Here's the view from Eau Claire, Wis.
Light pillars are produced when snow crystals reflect light from strong single source points like street lights or the moon or sun.
Here's more on light pillars from the National Oceanic and Atmospheric Administration:
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Long pillars of multicolored light streaking the sky seem like the perfect backdrop for impending alien invasion, but in reality, light pillars are a common effect that can be found all over the world.
They do come from above — not extraterrestrials, but tiny crystals of ice hanging in the atmosphere. Ice is very thin, shaped like plates with hexagonal faces. When ice drifts down through the air, it falls close to horizontally.
At the top and bottom are the faces with more area. Ice is very reflective, so when light hits those wider faces, it bounces around and reflects off more ice crystals.
That means we get these vertically stacked mirrors floating in the atmosphere. The light hitting it gets reflected up and up (or down and down, depending on the source), and becomes a radiant column in the sky.
Light can come from the sun, moon, cities, street lights — any strong light source. The way a light pillar looks depends on how high up the ice crystals are, what shape they are, how they’re angled, and how far away the light source is.
Great Lakes ice cover: highest in 4 years
Ice cover on the Great Lakes is at the highest point in four years. 50.6 percent of the Great Lakes is now ice covered according to NOAA.
That's the highest level of ice cover on the Great Lakes in four years, according to the Canadian Ice Service.
Lake Superior is now sporting 54.7 percent ice cover. That's also the highest level in four years. Last year Lake Superior had just 4.1 percent ice cover on this date.
It turns out small shifts in winter temperatures of only about 3 to 4 degrees can make the difference between little ice and lakes completely ice covered.
Milder next week
Temperatures remain chilly this week. Milder air begins to filter into Minnesota next week.
NOAA's Global Forecast System and the European mode still crank out highs in the 20s and 30s next week. An even milder flow may arrive the week of Feb. 19.
Hang in there Minnesota!