Are Tornadoes Afraid of Heights? Why We Don’t Hear about Mountain Tornadoes (Photo Credits: LInda Butler, Kathryn Prociv)
An EF0 tornado occurred near Eagle Nest Lake State Park in northern New Mexico on August 9, 2018. No injuries or fatalities were reported, however, a hay barn was destroyed, an RV knocked over, and reports of a damaged transformer and downed power lines. Golf-ball sized hail was also reported with this storm (Linda Butler).
Almost 4 years ago, one of the most photogenic tornadoes in recent New Mexico memory touched down near Eagle Nest Lake, a little over 200 miles northeast of the state’s most populous city of Albuquerque. What may come as a surprise to most is that this tornado happened in mountainous country, where Eagle Nest Lake sits at roughly 8,300 feet in elevation, surrounded by the high peaks of the Sangre de Cristo mountain range. There is a common myth that tornadoes do not occur in mountainous locations, but tornadoes can happen anywhere. In fact, out of the top 10 most fatal or injurious tornadoes in New Mexico, 4 of them happen to have occurred in Colfax County, where Eagle Nest is located.
Mountain tornadoes are most common in June and July, but have been documented every month except for November, December, and January. While most mountain tornadoes are weak and short-lived, one example is the F4 Teton-Yellowstone tornado that touched down July 1987. It traveled near 10,000 feet above sea level up the Grand Teton Mountain Range and crossed the Continental Divide. The higher it climbed, the weaker it became. As Kate Kershner of HowStuffWorks says, “For a more accurate picture of tornadoes, we need to acknowledge that they don't have any pet peeves. Things tornadoes love: destroying stuff. Things they're afraid of: nothing. Not cities, not the Mississippi River, not the Rocky Mountains. Give a tornado a cookie, and it will take that cookie, crumble it, throw it back in your face at 200 mph (322 kph) and then rip out”. Maybe tornadoes have a weak spot after all- a fear of heights.
Just because tornadoes are often observed traveling miles across the flat terrain of the Great Plains doesn’t mean that they can’t travel rugged terrain or climb to higher elevations. Tornadoes aren’t only limited to traveling on land either; they can also move over bodies of water (at which point they become waterspouts). The reason why mountain tornadoes aren’t as frequent has to do with the fact that the cooler, more stable air (which isn’t favored for severe weather development) is generally found at higher elevations. Tornadoes occur most often in the Great Plains, known for the best conditions for tornado formation (namely the humid, unstable air that often leads to severe thunderstorms and sets the stage for tornadoes). The general golden rule when talking about higher elevations is, “the higher you go, the colder it gets”. The cooler, more stable air found in mountains dampens low-level atmospheric instability, keeping storms from becoming severe or dissipating them entirely.
Tornado reports from 1950-2011 courtesy of the Storm Prediction Center (left); Elevation (in meters) across the continental United States. Gaps in tornado coverage are evident across the Appalachian Mountains (particularly over West Virginia). The Rocky Mountains also provide a sharp western boundary to the tornado reports found across the Great Plains. Maps by Kathryn Prociv.
Terrain does not physically disrupt a tornado if atmospheric conditions on both sides of the ridgeline are supportive of tornadoes, but storms often break up when encountering friction of the rough terrain of the mountain’s windward side. In fact, there is some research suggesting that rotating updrafts with supercell thunderstorms and perhaps tornadoes actually intensifies while going downhill on the ridgeline; the column of air lengthens and tightens, causing it to spin faster, much like a figure skater pulling in her arms, gaining instability and ingesting rotating air when moving over a sharp temperature gradient. The orientation of such ridgelines from southwest to northeast, such as the Appalachians, tends to trap cooler, more stable air to the east and southeast.
And finally, it’s much harder to spot a tornado in a mountainous area. If you’re looking at a funnel cloud along the ridgeline, the terrain may obscure if the funnel is actually touching the ground. Additionally, fewer people live in these high elevation locations, and now you’ve got a recipe for less noticeable tornado activity.
Regardless, the healthy approach to tornado risk is knowing that sometimes they do occur in mountainous regions. Most are brief and weak, but a few can stay on the ground for many miles and become destructive. Still, it’s a good idea to keep in mind tornado safety (i.e. heading for an interior room on the lowest floor with no windows) when a tornado warning is issued or you feel instinctively that the storm outside just doesn’t seem normal.
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©2022 Meteorologist Sharon Sullivan