CHEYENNE – Meteorologists from the National Weather Service say a landspout tornado was observed Sunday afternoon near Burns, briefly crossing over Interstate 80 between mile markers 377 and 381.
A fence south of I-80 near Burns suffered the only reported damage from the landspout tornado, according to Jeanine West, Cheyenne/Laramie County Emergency Management director.
“We were really lucky,” West said.
NWS-Cheyenne meteorologist Andrew Lyons said a tornado warning was issued at about 2:54 p.m. when the report came in from an observer. Some residents and observers sent photos and videos to the NWS Facebook page.
He said the tornado was not considered a classic supercell tornado, as it did not have an attached mesocyclone with the storm.
“The rotation in the tornado itself originates from the ground, as opposed to an apparent thunderstorm,” Lyons said.
And that, he said, makes these tornadoes extremely difficult to predict because of a lack of evidence on radar beforehand.
“If you’re familiar with the way that we issue tornado warnings, a lot of times we’ll say that there’s radar-indicated rotation,” he said.
“What we’re detecting is rotation from the thunderstorm before it touches the ground. In this case, the rotation came from a small wind-shift boundary in the low levels that was intensified by a thunderstorm developing on top of it.”
Landspouts are caused by a concentrated area of low-level winds spinning near the ground.
“That spin gets concentrated as a thunderstorm develops,” he said. “If you’ve heard of the analogy of a figure skater spinning with her arms out and as she pulls her arms in, you actually intensify the spin.”
Lyons said it’s important to understand that landspouts are considered tornadoes by definition and can be dangerous.
He said the definition of a tornado is a “violently rotating column of air in contact with the cloud and the ground.”
“They are tornadoes, and we treat them like tornadoes,” Lyons said. “They tend to be weaker because they don’t have that same spin that a lot of other storms do, but they can produce damage the same as a regular tornado.”
Lyons said residents can reach out to the National Weather Service on Facebook and Twitter with any weather-related questions.