Karla Dorman
... a landspout and a tornado. Thought they were the same.
Thank you in advance for answering my question.
Thank you in advance for answering my question.
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Wes Carter
EF5
Landspouts are tornadoes that form from boundary layer dynamics instead of mesocyclone dynamics. They are still technically tornadoes because it is a rotating column of air that is in contact with the ground and connected to the cloud base. They generally are weaker than supercelluar tornadoes and have a more even and tubular appearance.
The tornadoes we most often are chasing form from supercell thunderstorms. They have more potential to become powerful than do landspouts. And for me, they are easier to guess where they will happen. I find landspouts to be elusive, but that's probably because they are most often associated with higher cloud bases and drier climates such as Colorado. I'm in Tennessee, and I've never heard of a landspout out this far East. I'd be interested in finding out how far East they have formed.
The tornadoes we most often are chasing form from supercell thunderstorms. They have more potential to become powerful than do landspouts. And for me, they are easier to guess where they will happen. I find landspouts to be elusive, but that's probably because they are most often associated with higher cloud bases and drier climates such as Colorado. I'm in Tennessee, and I've never heard of a landspout out this far East. I'd be interested in finding out how far East they have formed.
Peter Wharton
EF2
My understanding is that a landspout and a non-tornadic waterspout are essentially the same weather phenomena, as they are not driven by a mesocyclone/rotating thunderstorm but by updraft/thermal dynamics effects between the ground/water and the cumulus clouds above them.
Here's a Wikipedia quote - "most are much weaker and caused by different atmospheric dynamics. They normally develop in moisture-laden environments as their parent clouds are in the process of development, and it is theorized that they spin up as they move up the surface boundary from the horizontal shear near the surface, and then stretch upwards to the cloud once the low level shear vortex aligns with a developing cumulus or thunderstorm. Weak tornadoes, known as landspouts have been shown to develop in a similar manner".
A tornadic waterspout and a tornado are driven by rotating mesocyclones - the difference merely being that one occurs over water and the other over land - the classification scheme outlined by NOAA. I've always though this distinction was somewhat spurious as a tornado on land could easily move over a small lake and by definition change from tornado to waterspout to tornado back again, which seems pedantic.
Here's a Wikipedia quote - "most are much weaker and caused by different atmospheric dynamics. They normally develop in moisture-laden environments as their parent clouds are in the process of development, and it is theorized that they spin up as they move up the surface boundary from the horizontal shear near the surface, and then stretch upwards to the cloud once the low level shear vortex aligns with a developing cumulus or thunderstorm. Weak tornadoes, known as landspouts have been shown to develop in a similar manner".
A tornadic waterspout and a tornado are driven by rotating mesocyclones - the difference merely being that one occurs over water and the other over land - the classification scheme outlined by NOAA. I've always though this distinction was somewhat spurious as a tornado on land could easily move over a small lake and by definition change from tornado to waterspout to tornado back again, which seems pedantic.
Skip Talbot
EF5
Landspouts are tornadoes. They are a particular type of tornado, so not all tornadoes are landspouts. To be more specific what you probably think of as a classic tornado is what can be more specifically referred to as a supercellular tornado. See http://www.stormtrack.org/forum/showthread.php?t=20933 for a recent discussion.
Paul Knightley
EF5
Yes, the answers above pretty much say it. A 'landspout' is a rather loose (IMO) term for a non-supercell tornado. However, it tends to detract from the fact that it's still a tornado, so I would discourage its usage.
We know that tornadoes form under difference convective situations - however, fundamentally most tornadoes form via some kind of stretching of vorticity, whether it's under a mesocyclone or not. So whilst it is very useful and academically interesting/important to determine what kind of storm was present, etc etc, they should still be called tornadoes. And of course waterspouts are just tornadoes, only over water!
We know that tornadoes form under difference convective situations - however, fundamentally most tornadoes form via some kind of stretching of vorticity, whether it's under a mesocyclone or not. So whilst it is very useful and academically interesting/important to determine what kind of storm was present, etc etc, they should still be called tornadoes. And of course waterspouts are just tornadoes, only over water!
Neil Schostag
I've been hearing the term Gustnado. Is that a mild form of what your talking about or is that not even in the ballpark? I've pictured it as what we used to call a Dust devil, which could form with no T/S activity
neil
neil
Jason Boggs
Yes Neil, a gustnado is a small spinup usually on the leading (outflow) portion of the storm. It is not considered a tornado, although it sometimes can cause minor damage.
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