It is the time of year for snow to be falling in Nebraska, and indeed the conditions are right for moisture to fall from the sky as snow. However, there are no suitable weather systems moving through the state. No matter — Nebraskans are making their own weather today thanks to a few industrial plants, which are causing a dense band of snowfall.
Residents of eastern Nebraska started to suspect something was amiss on Monday when they were treated to an unexpected burst of snow. A full two inches of the stuff fell in the space of a few hours, and the snow returned on Tuesday morning. There weren’t any lingering weather systems, so what gives?
The National Weather Service (NWS) in Omaha sent a tweet late on Monday morning suggesting that the unexpected snowfall could be thanks to the steam output from power plants in Norfolk, Nebraska. A few hours later, the account confirmed this was man-made snow, but said it was from “plants” rather than power plants specifically. Residents of the area have pointed to a pair of facilities near Norfolk: a steel manufacturer and an ethanol processing facility. One Twitter user wondered if the steam could be from a nuclear power plant and if said steam would be radioactive. The NWS assured him it was not nuclear steam. That’s a relief!
The NWS compared the phenomenon to lake-effect snow. This process, which is familiar to anyone living near the Great Lakes, involves cold air moving across the surface of a warmer body of water. Moisture from the lake gets swept up by the cold air, eventually falling as snow.
In this case, the NWS says there was a temperature inversion in the atmosphere over Nebraska — a layer of warm air above the cold ground-level air bottled up the steam. With temperatures in the mid-20s, the moisture in the steam became snow and drifted down in a swath covering about 100 miles. The direction of the snow moved eastward across the state on Tuesday, reaching the Omaha area.
This is not the first instance of perfect atmospheric conditions causing man-made snow, but we rarely get such a clean radar image of the event. So, this is not a viable way to ensure a white Christmas, but it might provide some overtime for snowplow drivers in Nebraska.
Top image credit: National Weather Service
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