National Weather Service United States Department of Commerce


A low pressure system brought strong (both thunderstorm, and non-thunderstorm) winds, tornadoes, dust, snow, and record temperatures into eastern Nebraska and western Iowa. The event was determined to be a derecho meeting the criteria of wind damage extending more than 250 miles, including wind gusts of at least 58 mph and numerous gusts of at least 75 mph.

The event began with non-thunderstorm winds greater than 58 mph in southeast Nebraska and southwest Iowa. Falls City had a peak wind pre-storm wind of 62 mph around 2 pm. Temperatures soared in the afternoon with many locations observing temperatures in the 70s, which is approximately 40° above normal. Shenandoah and Sidney both recorded a maximum temperature of 75°, the highest temperature ever recorded in the month of December for Iowa. Omaha, Lincoln, and Norfolk all set maximum temperature records, with Omaha and Lincoln both breaking the previous record by 10° or more. The stage had been set for the day as the normal diurnal pattern was interrupted with temperatures beginning to rise around 3 to 4 am, well before sunrise.

An influx of moisture contributed to the increased instability that would later help sustain the damaging derecho. Dew point temperatures in eastern Nebraska were observed in the upper 50s while in southwest Iowa they peaked at 64° at Harlan. The dew point temperatures were 30° warmer than climatic average for air temperature. The dew point temperature at Omaha reached 61° which would have matched the previous maximum air temperature record. Storms developed in northern Kansas around 3 pm, and quickly arrived into the OAX service area as they were moving between 60 to 80 mph. The first thunderstorm warning in the area was issued at 4:16 PM. The line of storms produced 25 confirmed tornadoes (9 EF-2, 14 EF-1, and 2 EF-0). The strongest measured wind gust was 92 mph at the Lincoln Airport. By 5:30 pm, the line of storms had cleared the service area.

The passing of the derecho was not the end of the event. Strong winds behind the cold front were nearly as strong as the straight line winds from the storms. The peak post-frontal wind gust was 70 mph, nearly matching the 74 mph wind gust measured from the derecho. These winds persisted for several hours and carried dust from Kansas which reduced visibility to a couple of miles at a few locations. The wind also carried a smell of smoke from large grass fires in Kansas.

Finally, to cap off the event, measurable snow up to a 0.5 inch fell in the northwest portion of the OAX service area.

Radar Loop of Storm System. Click to enlarge.
nws logo Media use of NWS Web News Stories is encouraged!
Please acknowledge the NWS as the source of any news information accessed from this site.
nws logo