Christmas. Images of snow-filled streets, holiday lights, hot chocolate, cold weather, and more fill the imagination. Christmas is almost synonymous with snow and winter in the northern hemisphere. Many wish for a white Christmas each year. Yet sometimes, Mother Nature does not play ball with that ideal.
In 2016, some Nebraskans spent their Christmas not watching the snow fall but heading to the basement as tornado warnings were issued. An unusual storm system brought a line of strong storms, with a few tornadoes over southern Nebraska and heavy rain elsewhere. As night fell, the winds cranked up over central Nebraska, where hurricane-force winds outside of any storms caused damage.
THE SET-UP
How do tornadoes happen in December this far north? It's uncommon but possible (see: December 15, 2021). Tornadoes (and thunderstorms) need four basic ingredients to form: moisture, instability, wind shear, and lift. The reason severe weather is common in spring is because this is when the four ingredients overlap the best. We have moisture and instability, but not much wind shear in the summer. It's reversed in the winter with plentiful wind shear, but no moisture/instability. Yet rarely, enough can make it this far north in the winter for severe weather.
On Christmas Day 2016, a very powerful low-pressure system entered the central Plains. The wind shear with this system was extreme and would contribute to the strong winds overnight. This system was able to pull up warm air far north, high temperatures in Omaha reached the 50s on Christmas Day. Instability was somewhat weak, but by late December standards, it was enough for severe weather in some parts of the region.
THE STORMS AND TORNADOES
By the late morning of Christmas, a thin line of thunderstorms developed over Kansas and southern Nebraska. With little instability, the line was marginally severe with 50-60 mph wind gusts along the leading edge. The most severe weather was over Kansas and southern Nebraska. This included three weak tornadoes in the Kearney vicinity, all of which caused damage to trees, power poles, irrigation pivots, and sheds. No one was hurt or killed in these tornadoes. Outside of a tornado in Pawnee County in 1975, the three tornadoes from Christmas 2016 remained the only tornadoes in Nebraska for December before the December 15, 2021 tornado outbreak.
As the line of storms moved into eastern Nebraska, it quickly outran the little instability it had. Winds were 40-50 mph as they crossed over the Omaha metro, doing little damage except to small branches in the metro. The storm produced heavy rainfall, 0.77" was recorded at Eppley Airfield, impressive for December.
HIGH WINDS OVER CENTRAL NEBRASKA
With the storms moving into Iowa, many felt the weather was over. For eastern Nebraska, it was, but it was a different story over central Nebraska. The high winds were contained above the surface within the low-pressure system. That evening a pocket of dry air was wedged into the system, forcing the winds to the ground. For several hours, winds as high as 80 mph screamed through central and northeast Nebraska.
Christmas inflatable decorations were ripped from their moorings and sent across neighborhoods. In Grand Island, the high winds triggered the outdoor warning sirens, urging people to remain inside through Christmas evening. A semi-truck was blown over on I-80 near Kearney. Wind damage to trees, power poles, and small buildings was common from the Tri-Cities through Northeast Nebraska. In Columbus, tree damage was apparent throughout the town. Power poles were snapped on US-81 between Columbus and Norfolk. In Norfolk, several fires were started by power lines.
Overall, it was one of the largest high-wind events in recent Nebraska memory. This, and the tornadoes, made Christmas 2016 one to remember for many in the Cornhusker state.
