Was there a tornado in Maine last week? Is a landspout a tornado? How can a cold core funnel produce a landspout, anyway? In this week's episode, I take a deep dive into a very interesting weather event that took place in Maine last week.
Prefer to read about the landspout? You will find a written version of what I said below the video.
So, a landspout “touched down” in Maine back on May 2nd. This is despite the fact that landspouts start from the ground and move upwards to the cloud. A landspout is technically a type of tornado, but the way they form is very different from a traditional tornado. A traditional tornado is formed from a supercell thunderstorm while a landspout forms on the ground from rotation not associated with a supercell and work up to the cloud. Landspouts are almost always very weak, registering winds below EF0 strength. The one in Maine saw winds of 55mph, EF0 starts at 65mph. Landspouts are typically created when convergence of surface boundaries meet the updraft of a thunderstorm and create circulation. The circulation is pulled upward toward the base of the cloud.
Things get kind of complicated in Maine’s case. The storm report in Maine states that a cold core funnel briefly touched the ground, creating a landspout. This is why it was said that the landspout in Maine touched down, even though landspouts are supposed to start on the ground already. A cold core funnel is created by a temperature contrast between very cold air aloft, the cold air at altitude in New England at the beginning of May was nearly record breaking for the time of year, and milder air at the surface, it was in the 50s on the ground at the time of the formation of the funnel. Cold core funnels very rarely make it all the way to the ground, but in Maine’s case, it did. When these funnels make it to the ground, they’re considered landspouts since they can’t be called straight tornadoes since they are very weak and they did not come from a supercell.
What’s interesting about this is the fact that cold core funnels drop from the cloud while traditional landspouts rise from the ground. There’s debate about whether or not landspouts truly can be considered tornadoes, however, the National Weather Service’s official definition of a landspout says "a tornado that does not arise from organized storm-scale rotation and therefore is not associated with a wall cloud (visually) or a mesocyclone (on radar). Landspouts typically are observed beneath Cbs or towering cumulus clouds (often as no more than a dust whirl), and essentially are the land-based equivalents of waterspouts." The definition states right off the bat a tornado, so it is a type of tornado despite having major differences. I guess maybe it’s not a debate so much as some confusion. This article states in the title, "Landspout touches down in western Maine, not a tornado." Toward the end of that same article, it states "A landspout tornado is a tornado." Another article states that landspouts are not tornadoes as they don’t form from supercells.
The definition of a tornado from the National Weather Service is "a violently rotating column of air touching the ground, usually attached to the base of a thunderstorm." The NSSL states that a tornado is "a tornado is a narrow, violently rotating column of air that extends from a thunderstorm to the ground." It also does not mention that it has to come from a supercell. This is interesting since Maine’s cold core funnel clearly did not come from a supercell, but it still dropped from the cloud. NSSL states that a tornado extends from the thunderstorm to the ground. Since the cold core funnel started at the base of a thunderstorm and dropped to the ground, couldn’t it be called a standard tornado, after all neither definition states the storm has to be a supercell? I guess that’s the real debate with this phenomenon. Anyway, the landspout in Maine caused some minor tree and shingle damage. It also tipped a small trailer. Again, Maine’s landspout was estimated to have winds of 55mph. So that’s where I’m gonna leave this for now, you won’t find coverage like this on your local news, here at New England Storm Center, we dive deep into New England’s weather.
