Should the terms waterspout, landspout etc be dropped?

[Paul Austin]

Thank you for posting this thread, Sam. I've often found it interesting to note how various people use the term tornado vs. waterspout vs. landspout. I've even had a seasoned NWS meteorologist from JAX reply to my use of the term "landspout" with perplexity - "landspout...what the?" as if he had never even heard the term before.

As a Florida native, I personally prefer the use of the term "waterspout" to refer to the convective but not so severe vortices that occur during summer months over the Gulf and shallow Atlantic waters of coastal Florida. These very often occur in the absence of any true organized thunderstorm, but rather are supported by a benign convective cloud cluster. The possible danger from such a storm is typically on a vastly different scale than that of a vortex produced and supported by an organized severe thunderstorm. Since "false alarms" are problematic in leading to public complacency, I would prefer to warn the public of such danger only when vortices are supported by organized thundertorms, whether supercellular or otherwise. My opinion regarding the use of the term landspout is much weaker.

I recognize the difficulty and confusion, especially where doppler data is unavailable. Since doppler is readily available here, I have to differ in opinion with Doswell above, though he is much more qualified in his written opinion and body of work

I appreciate everyone's opinions and insite here. I have to say that I even enjoyed the banter between members of TORRO and others, if only for the entertainment value

 

[cdcollura]

The Tornado Spectrum "Triangle"

Good day,

In my opinion, a TORNADO is a TORNADO, period. After all, whether it's a landspout, mile-wide wedge, or gustnado, the NWS warning text puts it as a "tornado" anyway.

Now, this brings up another subject...

We (storm chasers and scientists alike) always study tornadoes by their mechanism of formation, such as "mesocyclone" (supercell) induced, forward-flank (gustnado), or just plain "landspout" (non-meso in most cases).

I conjured up the following diagram below...

In the diagram above, a triangle depicts all the possible tornado types (except waterspouts, which are marine, but in this case we'll focus on the plains for simplicity).

This diagram was actually inspired by a chase in Cozad, NE on May 17, 2005 with Scott Blair, Eric Nguyen, Jeff Gammons, Tony Laubach, Scott Currens, and myself. We intercepted what was like a true landspount, but developing under a weak "meso-like" feature, and was more displaced towards the front-flank of a "tail-end charlie" cell in a storm line segment. Very strong S winds were ahead of this storm system, and light N winds behind it as a cold-front was present as well.

Above is a picture of what we saw...

We politely argued for hours amongst ourselves, "What would it be? a landspout?" ... "No, was a meso-cyclone tornado that looked like a landspout?" ... "How 'bout a gustnado, looked like one, but was more of a landspout? - with a weak RFD slot near it?" ... "Huuumm???"

Finally, in the dusty rear window of my chase SUV / Van rental, we drew a triangle, just like the diagram above. On the top, the non-meso "landspout". On the lower-left, a real supercell tornado. On the lower-right, a gustnado. The example we argued about here, was placed in the triangle, more between the supercell and landspout 'corners' and away from the gustnado because first of all, it was not outflow dominant. Second, it was a landspout in appearance, however, third, it looks like a weak meso is present due to an RFD like "punch" to the far right under the rain-free base.

Below is a picture of the debris cloud associated with the landspout, so it was quite strong.

So in conclusion, here is my opinion...

1). For the GENERAL PUBLIC, use the single term 'tornado'.

2). For the scientific community (including chasers), use the multiple terms, and variations of such as I described above.

This is all open to debate, so talk amongst yourselves about it!

Take care...

Chris C - KG4PJN

 

[scott r currens]

I remember the dusty triangle, we were even going to make t-shirts so we could point to a spot in the middle and say that is what we saw. It took me a year and another Non-mesocyclone/Gustnado hybrid (5/24/06) to put it on paper.

http://www.violentplains.com/Tornado%20Classification.htm

I am glad that I am not the only one to remember it.

 

[MatthewCarman]

I know the UK has TORRO but do they have a group like the NWS or NOAA? Who issues thier watches/warnings?

 

[Dave Clarke]

Hi Matthew, no there's no official body that issues watches/warnings etc apart from Torro who you've mentioned. The UK Met Office releases thunderstorm warnings, and will mention "A risk of gusty winds" in the warning text, but that's about it.

 

[David Draun]

Back on June 25th around 7:10pm, near Ft. Meyers Beach, FL, a thunderstorm rapidly pulsed up to severe limits with a near 65 mph downdraft reported. This storm also produced a waterspout over Estero Bay in the Gulf Intracoastal Waterway. The waterspout moved onshore to Estero island, doing weak damage to apartment rooftops and throwing beach equipment and yard furniture around. I beared witness to this event from start to finish as I was looking out the car window. A small funnel began to rapidly rotate in the forward flank of the storm. As I approached Estero Island, I could see a rapidly swirling ground circulation with sand and larger pieces of "something" which from a distance I could not discern. The vortex finally "filled in" from cloud to ground as it finally moved over the Gulf. It became a very large waterspout with an estimated diameter of about 40 yards at it's height. It was at this point that I regretted not having my camera with me Anyway, the NWS Ruskin, FL office who recieved several dozen calls that evening about the event, including reports of the ground circulation and associated damage, did not call it a brief tornado. Which leads me to a question about waterspouts. This spout occured under the leading edge of a thunderstorm, making it not "fair weather." The thunderstorm, however was not a supercell. So with the two waterspout classifications of "tornadic" and "fair weather," which one was this?

From analyzing radar data, thunderstorm itself formed on a collision of outflow from a storm to the south, outflow from another storm to the northeast, and the sea-breeze from the west. Sort of like a mini-triple point! The severe downdraft for what the storm was warned for, occured underneath the back-edge of the precip. It was quite an amazing little storm, with a lot of CG activity, and a rainbow visible near the tornado/waterspout for the duration. Damn I wish I had my camera!

 

[rdale]

It would clearly be a landspout over water then ;>

 

[Martin North]

Tornado Vs Waterspout

I don't personally have any difficulty with Tornado, Waterspout, Landspout. They are essentially tornadoes.

However, the name is an assist, which in short passes information to others as to exactly what is being observed. This especially when radios etc are being used to pass information.

You really aren't going to stand at the shores of Marathon Key and report a Tornado or a Tornado over Water. No, you'll report a Waterspout.

Same with Landspout really. It's most likely to be a Convergence Zone Tornado.

I'd just prefer to keep 'Tornado' as an official term for that which is associated with a Mesocyclone.

On the question of warning and the Meto. The Meto do not really warn Severe Thunderstorms in the UK. In fact of the day I photographed two Supercells on the same day...there was no warning at all or mention.

Torro do have Convective Discussions, Watches and Warnings for the UK....and we did discuss the days potential at length which in turn led to me being out there.

The key thing to remember is that Torro is privately run and paid for by their membership. There is no governmental sponsorship at all...and all things considered we don't do a bad job.

Convective Discussions, Watches and Warnings are only issued by resident Pro-Mets btw...

 

[Willie Dines]

Evening Sam

I am glad that you have brought the arguement over here where is it almost certainly doomed to failure.

There is nothing wrong with using the term Landspout or Waterspout and you should not try to attempt to eradicate terms well recognised by chasers like me and others on here.

Tap tap tap

I second this wholeheartedly, as I have grown up studying tornadoes with the related terminology and classifications of various type of vortex structures and climates, and there are countless number of chasers that are familiar with this terminology, and so in that respect, it doesn't make sense to try and fix something that isn't broken

Willie

 

[Shane Adams]

Agreed. My point is, the public does not know that, or care. And because technically, a gustnado can be damaging, it still needs to be tornado warned if sighted.

I disagree. A visual sighting shouldn't warrant a warning because the events are too short-lived. By the time the warning reaches the public, the event is long gone. BTW, the poll needed a third choice: "Who cares?"

 

[Paul Knightley]

A "gustnado" is not a tornado anyway, surely?! It's an eddy whirlwind on the leading edge of the gust front. I suppose if the vorticity is caught and stretched by the updraught it then becomes a tornado, but it's certainly not one before hand and shouldn't be treated as such.

 

[Tomas Pucik]

To add a bit from foreign country, here in Slovakia, there is an immense trouble with nomenclature.
Before 1989, terms such as "supercell" or "tornado" were mostly unknown or abolished, often meteorologist referred to them as an Imperialistic events, that are mostly unknown to countries in Eastern Europe. :-D Instead, there were two terms to be used: A/ lesser funnel cloud which means exactly the same like like funnel cloud now and B/ greater funnel cloud which covered tornado and waterspout occurences. This is the way tornadoes were approached.

Nowadays, there is a trouble, as newer terms that came from western countries mix with the older ones. AS most of the tornadoes in Slovakia do not come from supercells but are mostly landspout or a gustnado in nature, it was thereofore determined to use tornado term to cover all such stuff. Therefore, you can not hear gustnado all landspout in our language ( there are no translations of these terms). One attempt to differentiate between supercellular and non-supercellurar events was in usage of term "minitornado" when whirl did not come from a mesocyclone.

To top it all, media sometimes here have serious problems to distinguish what is tornado and what isnt and last year I saw a huge title in newspapers calling for rare tornado occurence which was supported by photo....of very nice shelf cloud :-D

 

[George Limpert]

I definitely don't think that torn warnings should be issued for gustnadoes. I think it's sufficient to issue a significant weather alert or a severe thunderstorm warning depending on the threat.

In fairness, I can understand why some people would want torn warnings issued. The media and emergency managers react differently to severe t-storm warnings than to tornado warnings. Warning sirens typically aren't sounded for severe t-storm warnings and TV stations generally don't cut in to programming for severe t-storm warnings.

I think instead of issuing torn warnings, communities should use sirens and media should cut into programming for some severe t-storm warnings. Not every warning should be cause for this sort of reaction. However, on November 9, 1998, a tornado (which was rated F3) struck Columbia, MO in the early morning hours. No torn warning was in effect because radar didn't indicate a tornado. However, because particularly strong winds were expected within the squall line, an emergency manager sounded the sirens. There's also the derecho that tracked through St. Louis on July 19, 2006. Sirens weren't sounded until a tornado warning was actually issued. However, even before a tornado warning was issued, straight line winds caused injuries, property damage, and knocked out electricity to many homes and businesses in the area.

I don't think torn warnings should be issued for gustnadoes. However, I do think if winds are strong enough, it should merit a greater response from emergency managers and media.

 

[Eric Tourangeau]

Personnally, I would call them "landspout type tornado", or "waterspout type tornado", etc.... so the event would be a tornado, and landspout, waterspout, etc would be the TYPE of tornado. So, there is ONE name (tornado) but a type associate to the name to explain the kind of tornado that occured.

 

[MJ Poore]

The Meto do not really warn Severe Thunderstorms in the UK. In fact of the day I photographed two Supercells on the same day...there was no warning at all or mention.
...

That's because maybe what you were seeing werent supercells Martin? To you personally they were supercells, and no one can stop you from using that word.

This illustrates the need for consistency and applying properly agreed scientific definitions to things. The consequesnces of a landspout and a tornado are very different, one is dangerous and the other is not. One is formed in a supercell storm, the other can form at any time on most normal storms.
Calling a spout or a cold core funnel a convergence zone tornado or just a tornado as this Torro organisation do, is misleading and alarmist.

Real tornadoes are dangerous and the word should be used carefully. Not just to any old spin up. Nor should any old storm suddenly be a supercell, I personally am loath to use the S word unless it's hailing bricks, blowing a typhoon, and spitting out tornadoes (hopefully).