October is a time of cooler weather, soaking rain, and snow. However, in typical Nebraska fashion, October also has a history with tornadoes, most recently when an EF-4 tornado slashed through the east side of Wayne back in 2013. Other large tornadoes occurred in central and western Nebraska in October. Meanwhile, Iowa saw an F-5 tornado during the month when one went through the town of Belmond in October 1966, minutes after the homecoming parade wrapped up.
Another event in the October tornado history books stands out, October 9, 2001. That afternoon, a large tornado outbreak occurred over the central United States. The two hardest-hit regions were western Oklahoma and central Nebraska. In this installment of This Week in Weather History, we travel back to 2001 to see what caused such a strong tornado event in Nebraska in October.
THE SET-UP
Tornadoes require four key ingredients: moisture, instability, wind shear, and a trigger. Tornado season is in the spring because this is when we have all those ingredients available. By the summer, the moisture and instability are there, but we lose the wind shear as the jet stream moves northward. Then by the cooler months, we get the wind shear back but lose the moisture.
If we have all four ingredients, we can see tornadoes all year. Remember December 15, 2021 (and if not...you can read about ithere)? We had all the ingredients, with 32 tornadoes in our viewing area.
It was similar on October 9, 2001, we had all four ingredients. Moisture: dew points (the measure of moisture in the air) were in the low-60s, which is adequate for tornadoes in fall. Instability: we had that too, the amount of energy in the atmosphere was quite high by October standards. Wind shear: We had that as a large storm system moved through the central United States. The wind shear was most favorable in central Nebraska, where the low-pressure system enhanced the shear. Finally, the trigger: a cold front/dry line combo was moving across the central US, helping to create storms by forcing lift in the atmosphere.
That afternoon, supercell thunderstorms erupted from central Nebraska southward into western Oklahoma. The outcome was one of the larger localized tornado outbreaks in October in Nebraska and Oklahoma.
THE TORNADOES
Most of the tornadoes were clustered in central Nebraska, between Grand Island and Columbus. Most were weak, only doing damage to a few center pivots and trees. However, there were two stronger tornadoes in the outbreak. One occurred in Merrick and Nance Counties, while the other occurred in western Polk County.
The first strong tornado rated an F-2, occurred in northern Merrick County into southern Nance County. The majority of the damage was done to trees, but one farm home sustained significant damage. The damage at this home was placed in the $250,000 range in 2001 money (just under 500k in 2024 money).
The second strong tornado, an F-3, hit Polk County. It began in far northeast Hamilton County and moved northeast, then crossed into Polk County west of the town of Polk. This tornado continued northeast before lifting west of Osceola. The major damage was done just north of Polk, where a farmhome was completely leveled, leaving only a basement. The occupants of the home were not present when the tornado hit, sparing them any injury. More homes suffered significant damage as it continued northeast.
Another weaker tornado, an F-1, began in northern Polk County and crossed northeast in Merrick County. This tornado went through Silver Creek, damaging around a dozen homes and snapping trees. The tornado lifted before crossing into Platte County. Another brief F-1 hit near Duncan in southwest Platte County.
The damage totaled around 500,000 dollars (nearly $750,000 in today's money). The tornado outbreak was significant in Oklahoma, where one of the largest October tornado outbreaks occurred. Three tornadoes were rated F-3, including one that hit the town of Cordell, causing major damage.
In Nebraska, the October 9, 2001, outbreak was one of the larger outbreaks in October. Those storms eventually merged into a line that hit Omaha with gusty winds. Outside of the winds, Omaha was not greatly affected by the tornadoes.
