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Ed Lizard

What do you call a tropical funnel that touches down?

22 posts in this topic

I have seen tropical funnels near Houston and in New Iberia, and waterspouts when I worked in the Gulf, and the tropical funnels which usually happen near the coast look like waterspouts, but 'land spout' seems wrong, as the Plains land spouts on video I have seen look different.

 

I'd propose 'tropical tornado', but then what would one call the F-4 tornado that killed about a dozen on Galveston Island during Carla?

 

 

 

'Science teacher' calls this a 'stovepipe' at the end.  Too much TV?  (Thursday, Houston suburb of Manvel)

 

 

 

 

 

https://www.youtube.com/watch?v=-t4BZjMp-PE

 

 

Oh, hey, I forgot how to embed YouTubes...

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The answer to this question is simple...and complicated. First the simple. Technically a "tornado" is a "rotating column of air pendant from a cumuliform cloud and in contact with the ground". So most "landspout" tornadoes, nearly all "water spouts", and all "tornadoes" fall into that category. If there is rotation at cloud base and rotation at the ground, that's all you need.

 

What is the difference between a waterspout and a tornado? There is some debate on this topic. Not all "waterspouts" are "tornadoes" and not all "tornadoes over water" are waterspouts. Waterspouts form from a different dynamic process than supercell tornadoes, and are similar to non-supercell processes. The reason there is so much information on waterspouts relates to how common they are in the Florida Keys and other areas along the Gulf of Mexico. That lead to a research program in the 70s (if my remembrance is correct) to study their formation. Waterspouts generally form in weak updrafts and are pendant to the puffy "fair weather" Cu common during the summer months. "Tornadoes over water" tend to be pendant from a supercell thunderstorm.

 

Regarding the tornadoes in the video: First, they are NOT what any experienced person would call a "stovepipe"; Second, it's hard to make a definitive assessment from this video alone. I, however, am undaunted by the challenge and am not afraid to be wrong from time to time, so will make an attempt. Given the appearance of the storm and the weak, thready appearance of the funnels, they would seem to be a non-supercell tornado process, possibly a waterspout that wandered on shore. They are a (1) rotating column of air, (2) pendant from a cumuliform cloud, and (3) in contact with the ground. So they are "tornadoes" in either case.

Hope this helps.

 

--Kevin 

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The answer to this question is simple...and complicated. First the simple. Technically a "tornado" is a "rotating column of air pendant from a cumuliform cloud and in contact with the ground". So most "landspout" tornadoes, nearly all "water spouts", and all "tornadoes" fall into that category. If there is rotation at cloud base and rotation at the ground, that's all you need.

 

What is the difference between a waterspout and a tornado? There is some debate on this topic. Not all "waterspouts" are "tornadoes" and not all "tornadoes over water" are waterspouts. Waterspouts form from a different dynamic process than supercell tornadoes, and are similar to non-supercell processes. The reason there is so much information on waterspouts relates to how common they are in the Florida Keys and other areas along the Gulf of Mexico. That lead to a research program in the 70s (if my remembrance is correct) to study their formation. Waterspouts generally form in weak updrafts and are pendant to the puffy "fair weather" Cu common during the summer months. "Tornadoes over water" tend to be pendant from a supercell thunderstorm.

 

Regarding the tornadoes in the video: First, they are NOT what any experienced person would call a "stovepipe"; Second, it's hard to make a definitive assessment from this video alone. I, however, am undaunted by the challenge and am not afraid to be wrong from time to time, so will make an attempt. Given the appearance of the storm and the weak, thready appearance of the funnels, they would seem to be a non-supercell tornado process, possibly a waterspout that wandered on shore. They are a (1) rotating column of air, (2) pendant from a cumuliform cloud, and (3) in contact with the ground. So they are "tornadoes" in either case.

Hope this helps.

 

--Kevin 

 

I get what you're trying to say here, but they're still referred to as waterspouts. In the past, our office has referred to these operationally as "tornadic waterspouts", which is somewhat redundant. I'd like to see us start using the term "supercell waterspout" here to denote vortices in contact with the water resulting from either classic or TC supercells.

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I'm sort of irked whenever I hear someone say on TV a waterspout is simply a tornado over water...its true technically but I get the feeling a lot think of the supercell thunderstorm type tornado whenever they hear it. More often they should denote the 2 types.

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...not all "tornadoes over water" are waterspouts.

 

 

I'd like to see us start using the term "supercell waterspout" here to denote vortices in contact with the water resulting from either classic or TC supercells.

 

Please, pretty please, with sugar on top can we agree to not to do that? There's already name for "supercell waterspouts": tornado. There is absolutely no benefit for creating a new name for a phenomenon which already has a name. A supercell tornado over water is as much of a hazard to marine interests as it is to land-based interests. A "waterspout", however, is mainly a hazard to small craft. There are distinctly different processes responsible for the creation of each and it is possible, even easy, to distinguish between the two.

 

I know the term "waterspout" has been genericised to apply to any tornado over water. As meteorologists, however, we should know better and realize the "hazard space" for each is not interchangeable.

 

--Kevin.

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Please, pretty please, with sugar on top can we agree to not to do that? There's already name for "supercell waterspouts": tornado. There is absolutely no benefit for creating a new name for a phenomenon which already has a name. A supercell tornado over water is as much of a hazard to marine interests as it is to land-based interests. A "waterspout", however, is mainly a hazard to small craft. There are distinctly different processes responsible for the creation of each and it is possible, even easy, to distinguish between the two.

 

I know the term "waterspout" has been genericised to apply to any tornado over water. As meteorologists, however, we should know better and realize the "hazard space" for each is not interchangeable.

 

--Kevin.

 

Hey, we're on the same page - differentiation needs to be made, however it seems as though we disagree on how to go about it. I guess our different perspectives stem from the fact that I've always used AMS definition #1 for a waterspout ("In general, any tornado over a body of water") and tried to differentiate spout types, while you favor the more specific definition #2 ("In its most common form, a nonsupercell tornado over water).

 

In my 22 years of being an operational NWS meteorologist, I've rarely, perhaps never heard of a vortex, over, and in contact with, a large body of water, referred to simply as a "tornado", Would you advocate using the phrase "tornado" or "tornado over water" for inclusion in NWS Special Marine Warnings for supercell or tropical cyclone induced spouts, rather than "tornadic waterspout" or "supercell waterspout", to differentiate them from traditional waterspouts?

 

Is it your contention that marine users of NWS warnings, who are by nature, generally quite weather savvy, would better understand that, rather than using a descriptor for a waterspout type?

 

I'll have to ask our Marine PL what he thinks local boaters would favor/understand better.

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Good disco. This is a pretty dramatic video of a multi-vortex waterspout. Certainly not the avg waterspout many people may think of.

 

 

 

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Hey, we're on the same page - differentiation needs to be made, however it seems as though we disagree on how to go about it. I guess our different perspectives stem from the fact that I've always used AMS definition #1 for a waterspout ("In general, any tornado over a body of water") and tried to differentiate spout types, while you favor the more specific definition #2 ("In its most common form, a nonsupercell tornado over water).

In my 22 years of being an operational NWS meteorologist, I've rarely, perhaps never heard of a vortex, over, and in contact with, a large body of water, referred to simply as a "tornado", Would you advocate using the phrase "tornado" or "tornado over water" for inclusion in NWS Special Marine Warnings for supercell or tropical cyclone induced spouts, rather than "tornadic waterspout" or "supercell waterspout", to differentiate them from traditional waterspouts?

Is it your contention that marine users of NWS warnings, who are by nature, generally quite weather savvy, would better understand that, rather than using a descriptor for a waterspout type?

I'll have to ask our Marine PL what he thinks local boaters would favor/understand better.

Aren't nonsupercell tornados virtually impossible to predict, short lived and usually cause minimal damage?

Just curious if the terminology issue really comes up very often in real time, vs after the fact analysis.

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Aren't nonsupercell tornados virtually impossible to predict, short lived and usually cause minimal damage?

Just curious if the terminology issue really comes up very often in real time, vs after the fact analysis.

 

Yes, difficult, nearly impossible to predict with certainty, however, precursor atmospheric conditions favorable for "traditional waterspout" or landspout formation are well-known locally and are fairly easy to diagnose. And we do get real time reports of them, and their pre-cursor funnel clouds, fairly often here in FL.

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I apologize for the offense, none was intended.
 

Hey, we're on the same page - differentiation needs to be made, however it seems as though we disagree on how to go about it. I guess our different perspectives stem from the fact that I've always used AMS definition #1 for a waterspout ("In general, any tornado over a body of water") and tried to differentiate spout types, while you favor the more specific definition #2 ("In its most common form, a nonsupercell tornado over water).

When I was "investigating" meteorology in high school I came across definition #2 in many sources, including Encyclopedia Brittinica (http://www.britannica.com/EBchecked/topic/637532/waterspout). Granted they were all older sources, ca 1970s. I don't know the origin of definition #1 but realize this is the most common usage. In everything I had read on the topic, it seemed non-supercell waterspouts and supercell tornadoes over water occupy a distinct hazard space. NST waterspouts would tend to occupy, almost exclusively, the low end (EF-0, EF-1) side of the curve, while supercell tornadoes can vary anywhere from EF-0 up to EF-5. The distinction isn't so important for marine interests, since each phenomena represents a threat to life and safety, but for land-based interests, where the feature may come on shore, the distinction is significant.
 

 

Would you advocate using the phrase "tornado" or "tornado over water" for inclusion in NWS Special Marine Warnings for supercell or tropical cyclone induced spouts, rather than "tornadic waterspout" or "supercell waterspout", to differentiate them from traditional waterspouts?

Yes, I would advocate the use of "tornado" or "tornado over water" in SMWs. I'll have to check, but I believe our WarnGen templates already do this. There is no need to "officially" add new words to the lexicon in order to describe a phenomenon that already has a name, "tornado". Supercells produce tornadoes. They can occur over land or over water. This does not change the dynamic process that creates the feature, nor alter the damage potential of such a whirl.
 

 

Is it your contention that marine users of NWS warnings, who are by nature, generally quite weather savvy, would better understand that, rather than using a descriptor for a waterspout type?

 
For marine users, I doubt any distinction is necessary. A whirl is a whirl. Both types represent a hazard to shipping and recreational interests. The response to each should be the same, seek safe harbor until the storm has passed. My point is that we do not need to create another term to represent something that already has a term. Call it a "tornado", call it a "tornado over water", it makes no difference to me. "Supercell waterspout" doesn't add any special meaning, especially considering a supercell could produce a tornado over water, associated with the mesocyclone, or a NST along the forward-flank or rear-flank gust front.
 
Again, I apologize for the condescending language. It seems I was "too cute by half" to set the right tone. I do wish for this to be a serious discussion and have very strong feelings about the subject matter.
 
--Kevin

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Aren't nonsupercell tornados virtually impossible to predict, short lived and usually cause minimal damage?

 

Not as much as they once were. The environmental precursors that support non-supercell tornadoes are relatively well established (very steep, nearly dry adiabatic low-level lapse rates, strong ambient vertical vorticity, low 100 mb mixed-layer CIN, 0-3 km mixed-layer CAPE of 100 j*kg-1, and weak deep-layer shear). Abundance in one of those parameters may even compensate for deficiencies in others. The biggest challenge, at present, is the poor radar presentation of these circulations, which makes warning decisions extremely difficult, and reliance on spotter reports more crucial.

 

As for minimal damage, no, not exactly. Non-supercell tornadoes have caused damage up to (E)F-2 intensity in the past. They are certainly a threat to life and property, even on the low-end of the scale. Remember, an EF-0 tornado has sufficient strength to take large branches out of trees. Injuries and fatalities occur each year with EF-0 and EF-1 tornadoes.

(E)F-1 Fatalities, by year

  • 2014 - 2 (to date)
  • 2013 - 3
  • 2012 - 2
  • 2011 - 5, 1 EF-0 fatality
  • 2010 - 4
  • 2009 - 3
  • 2008 - 4
  • 2007 - 4
  • 2006 - 8
  • 2005 - 3
  • 2004 - 5, 1 F-0 fatality
  • 2003 - 3, 1 F-0 fatality
  • 2002 - 6
  • 2001 - 4, 1 F-0 fatality
  • 2000 - 2
  • 1999 - 6

15 year total: 64, 4 (E)F-0 fatalities

 

--Kevin

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I apologize for the offense, none was intended.

 

When I was "investigating" meteorology in high school I came across definition #2 in many sources, including Encyclopedia Brittinica (http://www.britannica.com/EBchecked/topic/637532/waterspout). Granted they were all older sources, ca 1970s. I don't know the origin of definition #1 but realize this is the most common usage. In everything I had read on the topic, it seemed non-supercell waterspouts and supercell tornadoes over water occupy a distinct hazard space. NST waterspouts would tend to occupy, almost exclusively, the low end (EF-0, EF-1) side of the curve, while supercell tornadoes can vary anywhere from EF-0 up to EF-5. The distinction isn't so important for marine interests, since each phenomena represents a threat to life and safety, but for land-based interests, where the feature may come on shore, the distinction is significant.

 

 

Yes, I would advocate the use of "tornado" or "tornado over water" in SMWs. I'll have to check, but I believe our WarnGen templates already do this. There is no need to "officially" add new words to the lexicon in order to describe a phenomenon that already has a name, "tornado". Supercells produce tornadoes. They can occur over land or over water. This does not change the dynamic process that creates the feature, nor alter the damage potential of such a whirl.

 

 

 

For marine users, I doubt any distinction is necessary. A whirl is a whirl. Both types represent a hazard to shipping and recreational interests. The response to each should be the same, seek safe harbor until the storm has passed. My point is that we do not need to create another term to represent something that already has a term. Call it a "tornado", call it a "tornado over water", it makes no difference to me. "Supercell waterspout" doesn't add any special meaning, especially considering a supercell could produce a tornado over water, associated with the mesocyclone, or a NST along the forward-flank or rear-flank gust front.

 

Again, I apologize for the condescending language. It seems I was "too cute by half" to set the right tone. I do wish for this to be a serious discussion and have very strong feelings about the subject matter.

 

--Kevin

 

Excellent points, all of them. I can see where "tornado moving onshore" in the case of TC-induced spouts moving toward/onto land might be preferred terminology. If you can, please let me know the verbiage that is used in your templates. I'm working with our AWIPS FP this evening, and I'll bring this up between him, our marine PL, and our SOO. II can PM you my work e-mail if you'd rather forward this info off line.

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Good disco. This is a pretty dramatic video of a multi-vortex waterspout. Certainly not the avg waterspout many people may think of.

 

 

I worked the radar at OKX that day, and remember this developing from a bonafide supercell thunderstorm. Issued a tornado warning for Bridgeport, which got damaging winds from the storm's rear flank downdraft, and dodged a serious tornado bullet as you can see.

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It was my understanding that landspouts - both near marine environments and in places like here in New Mexico where I'm at - are low level updrafts that get stretched up into a non supercellular updraft which is the same process that forms waterspouts.  If that is indeed the case then you'd simply call this tornado a landspout.

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Not as much as they once were. The environmental precursors that support non-supercell tornadoes are relatively well established (very steep, nearly dry adiabatic low-level lapse rates, strong ambient vertical vorticity, low 100 mb mixed-layer CIN, 0-3 km mixed-layer CAPE of 100 j*kg-1, and weak deep-layer shear). Abundance in one of those parameters may even compensate for deficiencies in others. The biggest challenge, at present, is the poor radar presentation of these circulations, which makes warning decisions extremely difficult, and reliance on spotter reports more crucial.

 

As for minimal damage, no, not exactly. Non-supercell tornadoes have caused damage up to (E)F-2 intensity in the past. They are certainly a threat to life and property, even on the low-end of the scale. Remember, an EF-0 tornado has sufficient strength to take large branches out of trees. Injuries and fatalities occur each year with EF-0 and EF-1 tornadoes.

(E)F-1 Fatalities, by year

  • 2014 - 2 (to date)
  • 2013 - 3
  • 2012 - 2
  • 2011 - 5, 1 EF-0 fatality
  • 2010 - 4
  • 2009 - 3
  • 2008 - 4
  • 2007 - 4
  • 2006 - 8
  • 2005 - 3
  • 2004 - 5, 1 F-0 fatality
  • 2003 - 3, 1 F-0 fatality
  • 2002 - 6
  • 2001 - 4, 1 F-0 fatality
  • 2000 - 2
  • 1999 - 6

15 year total: 64, 4 (E)F-0 fatalities

 

--Kevin

 

 

Or possibly F3?

http://en.wikipedia.org/wiki/1972_Portland%E2%80%93Vancouver_tornado

http://www.wunderground.com/history/airport/KPDX/1972/4/5/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA

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A squall line NST which does F3 damage? I would classify that as highly unlikely. Much more common is a supercell embedded within a squall line. So in this case, I would tend to believe this would fit the "tornado over water" archetype rather than the NST "traditional waterspout" archetype.

 

--Kevin

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A squall line NST which does F3 damage? I would classify that as highly unlikely. Much more common is a supercell embedded within a squall line. So in this case, I would tend to believe this would fit the "tornado over water" archetype rather than the NST "traditional waterspout" archetype.

 

--Kevin

 

I've never seen a supercell west of the Cascades, and I find it hard to believe one would occur in Portland with a temperature of 61°F and a dew point of 50°F. But I suppose stranger things have happened.

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I get what you're trying to say here, but they're still referred to as waterspouts. In the past, our office has referred to these operationally as "tornadic waterspouts", which is somewhat redundant. I'd like to see us start using the term "supercell waterspout" here to denote vortices in contact with the water resulting from either classic or TC supercells.

In Sept and October 100's of these form on cool crisp days over the great lakes. Never once heard of them referred to as a tornado.

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In Sept and October 100's of these form on cool crisp days over the great lakes. Never once heard of them referred to as a tornado.

 

Would those be cold air funnels?  Are the waterspouts off Galveston in the Summer the same animal as waterspouts that form over the Great Lakes.  Of course, I suppose cold Autumn air over still warm lakes would produce the kind of low level instability one sees in LES events.

 

I don't know.

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A squall line NST which does F3 damage? I would classify that as highly unlikely. Much more common is a supercell embedded within a squall line. So in this case, I would tend to believe this would fit the "tornado over water" archetype rather than the NST "traditional waterspout" archetype.

 

--Kevin

There were 3 EF3s in the morning QLCS in AL on 4/27/11.

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