According to the Weather Channel, there are only six known photographs of winter waterspouts in existence. Then, last week, Jordan Detters captured a good minute and a half of video, showing winter waterspouts dancing along the waves of Lake Superior near Knife River, Minnesota.
While water spouts are relatively common in warm months, producing one in the winter requires a pretty specific set of meteorological circumstances, writes Minnesota Public Radio's chief meteorologist Paul Huttner. Thus, the dearth of images. In fact, for one to form at all you need a temperature difference between the water and the air of 19 degrees C.
Winter waterspouts occur when meteorological conditions are just right. You need a bitter arctic air mass passing over relatively warm lake water, and just enough light, low level wind shear to get the rapidly rising air currents spinning nicely.
Saturday’s contrast between bitter arctic air (air temp was about -7 degrees at Two Harbors nearby) and relatively warmer lake water (offshore surface water temps were around 40 degrees) create an “enhanced lapse rate” as temps cooled rapidly with height above the water. That produces rising air, and the lift needed to generate strong updrafts. Slight wind shear gets the air spinning, and small vortexes can form into waterspouts over the lake.
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Biologist Nipam Patel and his team at UC Berkeley study how butterflies develop wing shape and color by performing surgery on caterpillars, creating translucent windows in their cocoons.
You know the drill. You go to the dentist and they ask you how often you floss. You lie through your teeth and say, “every day!” (Bonus points if you have some cilantro or chives stuck in your gums from lunch). You don’t want to keep up the charade any longer, but rubbing that tiny strand […]
The Raspberry Pi Foundation has done outstanding work packing a fully capable desktop computer into a package the size of a deck cards—especially one that only costs $35. But if you already have a working laptop, why should you care? Oh, how much you have to learn. Besides operating well as a compact digital media hub, […]
Custom coffee vessels are the perfect piece of office flair, but it’s just a matter of time before your VOTE FOR PEDRO mug will start to lose its relevant wit. Why not have a new one every day, with whatever silly nonsense you want sticking off the sides? You can save big on your novelty […]