FARGO — Tuesday evening shortly before 9 p.m., a small area of North Dakota southwest of Fargo experienced a meteorological phenomenon known as a heat burst. A weak shower near Lisbon, North Dakota, produced a rain shaft which dried up before reaching the ground. The air in this downdraft was heated as it fell by atmospheric compression. This process also dried the air considerably. As the air reached the ground, it fanned out over an area of Ransom and northern Richland counties with wind gusting to around 20-30 mph, a temperature which warmed by about 10 degrees to around 90, and a noticeable drop in humidity.
As heat bursts go, this one was relatively weak. In more extreme cases when the drying downdraft is from a much taller thunderstorm, there have been cases of temperatures warming to well over 100 degrees in the middle of the night accompanied by desert-dry air and damaging wind gusts.