From: "Dean Sgarbossa" To: Subject: Re: aus-wx: tornado climatology Date: Fri, 11 Aug 2000 20:10:43 +1000 X-Mailer: Microsoft Outlook Express 4.72.2106.4 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com
Hello Clyve and list,
    It is nice to hear from you again Clyve. I haven't seen you for quite some time. In your response to Australian Tornado Climatology, I agree with you that any cloud, vapour or air formation that does descent from a parental cloud is of great significance and importance and must be watched closely for they may cause damage to the ground and other structures. However, with all due respect, I must disagree with the classification of non-supercellular vortices being included as a tornadic event. I shall explain more in depth below. However, before I proceed, I would like to express the fact that I have a great respect and admiration for fellow weather enthusiasts and their opinions as well as tornado research thus far including the researchers themselves involved. I simply wish to share my observations of tornado research undertaken thus far.
 
    The classification of such phenomena is of great bewilderment amongst the public, weather enthusiasts and meteorologists alike. When tornado recording first began, not much was known about these vortices and hence, anything relating to a vortex appearance was classified as a tornado due to the definition at hand: "A tornado is a violently rotating column of air that extends from a dark cloud". This definition, and the numerous similar definitions that accompany it mislead the public and anyone that may have observed a vortex.
    On a technical basis, the origins of true tornadoes are associated from the rotational updraught associated with a supercellular thunderstorm (Cumulonimbus Incus). Since the exact origins of a tornado's birth are yet to be known and discovered, the exact classification scheme cannot be produced. Also, there is some dilemma whether a tornado can be produced by a multicellular thunderstorm. However, as recorded by Project Vortex and Josh Wurman from the University of Oklahoma, usually storms inheriting multicellular characteristic remain multicellular, but when the storm produces a tornado, the storm rapidly inherits characteristics of a supercellular storm bewildering many meteorologists and tornado researchers.
    Landspouts and other vortices are merely the result of strong thermal shear and wind shear. The parental cloud (usually cumulus mediocris, cumulus congestus and sometimes cumulonimbus calvus can be observed as being a thunderstorm when they are actually NOT, although they may appear to be.) For this reason, landspouts are often classified as tornadoes due to the eyewitnesses account. A perfect example of this can be seen with the so-called Cleve, SA "tornado". This event was entered into the BoM database as being a tornado, although it is clearly a landspout spawned from the strong wind shear present. The parental cloud is merely a cumulus congestus with a rather dark base confusing the eyewitness.
    Waterspouts are a dilemma to recording and researching tornado events for they are usually considered as being the same as landspouts just over water. However, they may also be tornadoes only occurring over water. For this reason waterspouts are usually ignored in many research efforts.
   
    Amidst the false belief that a tornado is anything replicating a rotating vortex, the true classification of a tornado must be published in order to prevent confusion and misconceptions.
 
    As for the current classification scheme: a vortex descending from the base of its parent cloud is classified as a tornado if the following two properties are present:
 
 the funnel clearly makes contact with the ground i.e. debris directly beneath funnel.
 
 the funnel is produced by a cumulonimbus cloud or lesser clouds that flank the thunderhead.
 
Note Photo: Tornado with obvious debris immediately beneath funnel spawned from a cumulonimbus cloud, (Sandon, Victoria). Copyright I. Kuiper.
 
    In regards to tornadoes occurring and forming in the lesser clouds that flank the thunderhead, these inflow clouds (usually cumulus congestus) can inherit rotation associated with the supercellular thunderhead and hence produce a tornado. This event should still be classified as a tornado.
    However, again due to the unclear causes of tornadogenesis, these intricate and technical details must be researched further before an accurate and irrefutable classification scheme can be developed.
 
Cheers,
Dean AL Sgarbossa
 
 
-----Original Message-----
From: clyve herbert <mesof5 at iprimus.com.au>
To: aussie-weather at world.std.com <aussie-weather at world.std.com>
Date: Friday, 11 August 2000 10:05
Subject: Re: aus-wx: tornado climatology

>Hi Dean
>In respect to reporting anything that comes out of a cloud it is important
>in study to watch everything that does poke out of any cloud system. from
>vapour vortices to F5 monsters even around the periphery of tornadoes small
>vortices appear they are all interconnected  along the line and in respect
>to land spouts its best not to separate this so called "type" from tornadoes
>or waterspouts. Infact according to Bluestien et al a landspout is simply a
>tornado developing within a non supercell cumulonibus or a congesting
>cumulus theres lots more but i have to fly regards Clyve Herbert.
>----- Original Message -----
>From: Dean Sgarbossa <deansgar at alphalink.com.au>
>To: <aussie-weather at world.std.com>
>Sent: Thursday, August 10, 2000 7:41 PM
>Subject: Re: aus-wx: tornado climatology
>
>
>> Hello Harald and list,
>>     On the topic of Australian tornado climatology, there is such a map in
>> existence, displaying tornado frequency for the whole of the continent.
>> However, in your case, it is not in the format of contour lines rather
>than
>> "frequency squares" representing the number of tornadoes per year
>normalised
>> to 10^5 sq km area, (Stewart C. Allen: BoM Technical Report 39, A
>> Preliminary Tornado Climatology - December 1980) Unfortunately this map
>only
>> covers the year spanning from 1950 to 1959, a very small period of time
>> considering the number of tornado occurrence in history. However, such an
>> accurate map is difficult to plot for a number of previous tornado
>reports,
>> especially early 1900's, are false and inaccurate. The term tornado in the
>> past was describing anything that appeared to have rotation present i.e.
>> dust devils, waterspouts, landspouts etc. etc... If all of the reported
>> tornado reports were to be present on a national map, the major regions
>and
>> densely populated cities would be the sole focus of tornado activity.
>> However, taking into consideration the Australian population and
>> ever-growing and extending towns and suburbs, the number of tornadoes is
>no
>> doubt going to sky-rocket through the roof and then...perhaps an accurate
>> climatology can be established. Past Australian tornado researchers, i.e.
>> Clarke, Hanstrum, Allen, Minor, Perterson, Lourensz (just to name a few)
>> have found this discrepancy and have attempted to bypass such flaws into
>the
>> investigation. Even the works of Clarke and Allen, the pioneers of
>> Australian tornado research had dilemmas concerning what exactly a tornado
>> was. Their reports and technical notes are based around the belief that
>> tornadoes were anything descending from a cloud. This is a huge
>discrepancy
>> which must be rectified in order to fulfill a successful and fruitful
>> analysis and hence, climatology.
>>
>> Yours sincerely,
>> Dean AL Sgarbossa
>> -----Original Message-----
>> From: Harald Richter <hrichter at enterprise.nssl.noaa.gov>
>> To: Australian Severe Weather Association <aussie-weather at world.std.com>
>> Date: Thursday, 10 August 2000 16:22
>> Subject: aus-wx: tornado climatology
>>
>>
>> >
>> >Hi Chasers:
>> >
>> >I have long been trying to get an idea what an Australian
>> >tornado frequency contor plot would look like.  To my
>> >knowledge there is no such map in existence which is
>> >a pity.  I have seen symbols plotted on an Australian map
>> >for individual severe/tornadic events which showed remarkable clustering
>> >of storms/tornadoes in certain areas.  These areas turned
>> >out to be Sydney, Melbourne, Adelaide, Brisbane, Perth
>> >etc. - you get the idea.
>> >
>> >
>> >Dean A. S. wrote:
>> >>>     The Queensland Highlands has a tornado occurrence of 1.2 per
>100,000
>> >>> square kilometres. The population density for the same area is 0.3 per
>> square
>> >>> kilometre. When the tornado occurrences are joined with the population
>> >>> density, the number of occurrences per 100,000 people is 4.0.
>> >
>> >Correcting for a population bias in tornado reports is not just a matter
>of
>> >normalising the population density to 1.
>> >If that was the case, a single event (1 per 100,000 km^2) caught by
>> accident
>> >in an unpopulated area (0.0001 people per 100,000 km^2, say) would create
>a
>> >whopping fat frequency bullseye (10,000 tubes).
>> >
>> >I have a feeling that the Australian database suffers greatly from
>> >under-reporting in most areas, possibly to the extent that
>> >a meaningful contour map of tornado frequencies cannot be drawn.
>> >
>> >Given the population clustering along the coast a perhaps better
>> >attempt of compiling an Australian severe storms climatology is
>> >the use of remote sensing devices.  Radar covers some areas and
>> >might be useful for those.  Cloud top temperature (CCT) can be montitored
>> >from space with decent spatial and temporal continuity, but then you
>> >have the impossible problem of relating CCT to tornado frequencies.
>> >
>> >
>> >>> This is
>> >>> approximately the same as the tornado density in the central Great
>> Plains
>> >>> states of the USA and half the density in the tornado alley in Central
>> >>> Oklahoma (Davies-Jones, 1985).
>> >
>> >The latest U.S. tornado climatology is work done by Harold Brooks at
>NSSL.
>> >Take a peek at
>> >
>> >http://www.nssl.noaa.gov/hazard/loops.html .
>> >
>> >Is Davies-Jones (1985) (journal?) a severe storms climo?
>> >
>> >
>> >>> According to Bart Geerts (University of Alabama and
>> >>> Huntsville) and Mosese Noke-Raico (Macquarie University), the Sydney
>CBD
>> and
>> >>> outer suburbs has the highest tornado density in Australia.
>> >
>> >For the reason stated above that finding does not fill me with joy.
>> >Do Geerts and/or Noke-Raico have any of their work on the web/ in the
>> literature?
>> >
>> >
>> >Here's a suggestion for ASWA:
>> >A collection of daily high-resolution IR/VIS images for every day between
>> >now and February would give us a decent idea regarding the
>> >storm distribution for *this* coming season.
>> >If this is done for several years we might be able
>> >to see an emerging pattern.
>> >Alternatively, a satellite archive might already allow us to
>> >do so.
>> >
>> >
>> >Oh yeah,  my guess for the 'hot spot':
>> >NC/NE NSW and SC/SE QLD - high SSTs and
>> >strong flow associated with those lows
>> >down south which reaches up that far north.
>> >
>> >Cheers,   Harald
>> >
>> >
>> >--
>> >-------------------------------------------
>> >Harald Richter
>> >NOAA/National Severe Storms Laboratory
>> >1313 Halley Circle
>> >Norman, OK 73069, U.S.A.
>> >ph.:    (405) 366-0430
>> >fax:    (405) 579-0808
>> >email:  hrichter at enterprise.nssl.noaa.gov
>> >web:    http://www.nssl.noaa.gov/~hrichter
>> >-------------------------------------------
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>> > message.
>> > -----------------------jacob at iinet.net.au------------------------------
>> >
>>
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> Embedded Content: Re aus-wx tornado climatology: 00000001,0d3d0b01,00000000,00000000 From: "James Chambers" To: Subject: Re: aus-wx: STORM: Re Huntly Tornado - New Zealand Date: Sat, 12 Aug 2000 00:30:52 +1000 X-Mailer: Microsoft Outlook Express 4.72.3110.1 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi John and all I just found a report on the event from www.stuff.co.nz and it starts off like this: "A mini-tornado struck Huntly this morning tearing off several roofs, downing power lines and uplifting trees." Hehehehe The rest of the report is here: http://www.stuff.co.nz/inl/index/0,1008,310323a10,FF.html On another note, it's cool and clear here in "Woody" (just south of Brisbane) just after Midnight on Saturday. Currently 6.8C after a max temp on Friday of 24.3C. On Friday morning my thermo recorded 2.3C - quite a surprise!!! Amberley scored 0C. Regards James Chambers PS: For those at the ASWA AGM - Have a good one!! >Re Huntly tornado > >The tornado that moved through and twisted for 5kms through the towns of >Huntly and Te Kauri in the northern Waikato at 7.30am Friday 11th was >probably close to a F2. >Lots of damage to roofs and reports of an actual shed with people in it >being lifted up off the ground. A washing machine was lifted and carried 60 >metres. >Unfortunately there are no storm chasers in the North Island and as I am >based in Christchurch where we don't get storms, no footage of the actual >tornado was made to my knowledge, mind you it was early in the morning. > >The tornadoes that we do get here in New Zealand are mainly on the west >coast of the country, in this case, I wouldn't be surprised if there were >waterspouts off the coast of Waikato. The upper level is very cold and the >Tassy Sea temps are quite warm and this trough did really spawn out with >some thunderstorm activity in western areas. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ Date: Fri, 11 Aug 2000 11:41:57 -0400 From: "Leslie R. Lemon" Subject: Re: aus-wx: tornado climatology To: "INTERNET:aussie-weather at world.std.com" X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id LAA16608 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com hello all. I have been absent from the list for sometime but obviously am back. I am getting into this discussion a little late and may cover ground already covered. Further, when I became aware of this discussion, I sent a message to Jane to see if she could post it. I have a copy of that, it follows: Phil Bagust wrote: > > Just looking at the Sunbury footage made me think. The funnel only > extends about 1/4 of the way to the ground. Now, it's clear that there's rotation > > on the ground and that it's a tornado, but my suspicion is that most of > the public only associate a tornado with a condensation funnel that goes all > > the way to the ground - presumably because that's what they've seen from > > images from the US. Could this have led to a significant underreporting > of tornadoes over the years? ie events just get reported as freak short lived > > storms because there's no condensation funnel on the ground? Would this > be common in winter events? Is there any reason why winter tornados would be > > less likely to form full condensation funnels? [less moisture available?] This is common and has been emphasized in U.S. spotter training programs beginning with the 1978 update. In fact, for "land spouts" this is the norm for the full lifetime of the tornado. In supercellular tornadoes, this is often the case for the first few minutes of the tornadoes life cycle and again, at the end of its life cycle. That is not to say that supercellular tornadoes will never be characterized this way for their full life time. In fact, in a June 8, 1974 outbreak in Oklahoma, Oklahoma city experienced an F3 tornado with a lifetime of about 15 minutes and a 20 to 30 km path length (as I recall) that never was characterized by a funnel cloud touching the surface. This is indeed, a problem with reporting "only" a funnel aloft. For this reason, it is wise to look very closely for a debris whirl or dust cloud beneath a funnel aloft and to do a damage survey beneath these locations after the fact. Apart from that discussion I have some other thoughts. The following definition of a tornado can be found: *Tornado - A violently rotating column of air in contact with the ground and extending from the base of a thunderstorm. A condensation funnel does not need to reach to the ground for a tornado to be present; a debris cloud beneath a thunderstorm is all that is needed to confirm the presence of a tornado, even in the total absence of a condensation funnel. Here he states " extending from the base of a thunderstorm". In reality that is not necessary. The land spout, the gustnado, and the flanking line tornadoes may all be produced by a towering cumulus prior to tstm formation. However, these are all tornadoes. In Chuck Doswell's essay on tornadoes he includes the following: "Definition : A vortex extending upward from the surface at least as far as cloud base (with that cloud base associated with deep moist convection), that is intense enough at the surface to do damage should be considered a tornado. This is without regard to the underlying surface, the existence/non-existence of a condensation cloud from cloud base to the surface, the depth of the moist convective cloud, the presence/absence of ice in the upper reaches of the convective cloud, the occurrence/non-occurrence of lightning within the convective cloud, or even the intensity of the phenomenon beyond some lower threshold. My broadened definition is designed to ignore what I consider to be incidental aspects of the situation. I believe that the physical process giving rise to an intense vortex is not associated with any of these coincidental issues and so the labeling of the real vortices that occur should not depend on them. It also excludes any phenomena not associated with deep moist convection, such as dust devils or "mountainadoes," and avoids making artificial and scientifically unjustified distinctions between "spouts" and tornadoes.[5]" Further, he states: "because I do not believe there is any scientific distinction of consequence between a waterspout and a tornado!" For what it is worth, I agree with the above. All for now. Les ************************ Leslie R. Lemon Radar, Severe Storms, & Research Meteorologist Tel. 816-373-3533, 816-213-3237 E-Mail: lrlemon at compuserve.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ Date: Fri, 11 Aug 2000 14:16:22 -0400 From: "Leslie R. Lemon" Subject: Re: aus-wx: tornado climatology To: "INTERNET:aussie-weather at world.std.com" X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id OAA17367 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Having said what I did in my pervious post on this, there is one other related topic and point I wish to make. It is human nature to place people such as myself and others, especially Chuck, who have researched and published on many of these topics in a position of being near "gods". Obviously, none of us are "gods" nor are we infallible, immutable, all knowing, etc. Those are attributes of only One. We obviously make mistakes, we can and are mistaken many times. One is authoritative only in comparison to some others. Thus, no matter what Chuck and other "authoritative" folks say or write, it should not be seen as the final word by any means and by anyone. The words (and definitions) by those of us in this business should never be seen as words that reduce or stymie differing ideas and opinions. Keep those minds turning and functioning and keep sharing dispirit ideas. Les ************************ Leslie R. Lemon Radar, Severe Storms, & Research Meteorologist Tel. 816-373-3533, 816-213-3237 E-Mail: lrlemon at compuserve.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "The Weather Co." To: Subject: Re: aus-wx: tornado climatology Date: Sat, 12 Aug 2000 06:00:07 +1000 X-Mailer: Microsoft Outlook Express 5.00.2314.1300 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Phil, I recall some of the TV footage I saw showed a condensation funnel nearly all the way to the ground. - Paul G. ____________________ The Weather Company Level 2, 7 West Street North Sydney 2060 Phone: (02) 9955 7704 Fax: (02) 9955 1536 twc at theweather.com.au ----- Original Message ----- From: Phil Bagust To: Sent: Friday, August 11, 2000 10:31 AM Subject: Re: aus-wx: tornado climatology > Hi all, > > Just looking at the Sunbury footage made me think. The funnel only extends > about 1/4 of the way to the ground. Now, it's clear that there's rotation > on the ground and that it's a tornado, but my suspicion is that most of the > public only associate a tornado with a condensation funnel that goes all > the way to the ground - presumably because that's what they've seen from > images from the US. Could this have led to a significant underreporting of > tornadoes over the years? ie events just get reported as freak short lived > storms because there's no condebsation funnel on the ground? Would this be > common in winter events? Is there any reason why winter tornados would be > less likely to form full condensation funnels? [less moisture available?] > > > ___________________________________________________________________ > Phil 'Paisley' Bagust - paisley at cobweb.com.au [Hm] - > Philip.Bagust at unisa.edu.au [Wk] > Paisley's Playpen at http://www.chariot.net.au/~paisley2 > "Java = [J]ust [A]nother [V]irtual [A]nnoyance" > > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "The Weather Co." To: Subject: Re: aus-wx: STORM : Huntly Tornado - New Zealand Date: Sat, 12 Aug 2000 06:00:48 +1000 X-Mailer: Microsoft Outlook Express 5.00.2314.1300 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi John, Were there any reports of hail? - Paul G. ____________________ The Weather Company Level 2, 7 West Street North Sydney 2060 Phone: (02) 9955 7704 Fax: (02) 9955 1536 twc at theweather.com.au ----- Original Message ----- From: John Gaul To: Sent: Friday, August 11, 2000 1:47 PM Subject: aus-wx: STORM : Huntly Tornado - New Zealand > > A tornado ripped through the Waikato town of Huntly in the North Island of > New Zealand this morning at 7.30am NZ time damaging houses and generally > making a bit of a mess in the town. > Not to sure of other details but will let you know as they come to hand. > > > > John Gaul > NZ Thunderstorm Society > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: Harald Richter Subject: aus-wx: what is a tornado? To: aussie-weather at world.std.com (Australian Severe Weather Association) Date: Fri, 11 Aug 2000 15:23:17 -0500 (CDT) X-Mailer: ELM [version 2.5 PL3] Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Dean, Hi list, > On a technical basis, the origins of true tornadoes are associated = > from the rotational updraught associated with a supercellular = > thunderstorm (Cumulonimbus Incus). Since the exact origins of a = > tornado's birth are yet to be known and discovered, the exact = > classification scheme cannot be produced. Yep. I think that's the main issue - a physically based classification scheme. We are beginning to learn that the atmosphere is full of vortices, visible ones and invisible ones. The spectrum is more continuous than originally anticipated, but it still allows some natural distinctions between vortices. An easy example is the difference between dust devils (no cloud present) and a "classic" tornado (big cloud present). But then we are getting into the waterspout/tornado distinction issue. Are waterspouts tornadoes over water or aren't they? Even, is the question relevant? One observation is this: I have not yet heard of a waterspout that had the intensity of a F3/F4/F5-type tornado. If there is indeed an intensity cutoff for waterspouts that is well below the maximum intensity for strong tornadoes, then it seems likely that some different physical mechanisms/parameters allow land-based tornadoes to grow stronger. If you wanted to distinguish between waterspouts and tornadoes cleanly, you would have to understand that "difference" first. For all I know me might one day wind up with a classification scheme that puts waterspouts and *some* tornadoes into one class, and *the remaining* tornadoes into another class based on consistently different physics. > However, as recorded by Project Vortex and Josh Wurman from the = > University of Oklahoma, usually storms inheriting multicellular = > characteristic remain multicellular, but when the storm produces a = > tornado, the storm rapidly inherits characteristics of a supercellular = > storm bewildering many meteorologists and tornado researchers.=20 Hmm, I am bewildered. BTW, how do storms "inherit" things? Cheers, Harald -- ------------------------------------------- Harald Richter NOAA/National Severe Storms Laboratory 1313 Halley Circle Norman, OK 73069, U.S.A. ph.: (405) 366-0430 fax: (405) 579-0808 email: hrichter at enterprise.nssl.noaa.gov web: http://www.nssl.noaa.gov/~hrichter ------------------------------------------- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ Date: Fri, 11 Aug 2000 18:00:29 -0400 From: "Leslie R. Lemon" Subject: aus-wx: what is a tornado? To: "INTERNET:aussie-weather at world.std.com" X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id SAA00358 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi again all: > > However, as recorded by Project Vortex and Josh Wurman from the = > > University of Oklahoma, usually storms inheriting multicellular = > > characteristic remain multicellular, but when the storm produces a = > > tornado, the storm rapidly inherits characteristics of a supercellular = > > storm bewildering many meteorologists and tornado researchers.=20 I am unfamiliar with the Josh Wurman study you refer to. Most of his observations have been using the X-band DOW radar which therefore, necessarily, confined his view to the region of the hook echo (a region less than ~ 5 km on a side). In those studies, the larger storm structure was largely unobserved (by that particular radar) and therefore unknown. Arguably, there are no single cell storms. Early on during the recognition of supercells, the radars were considerably lower in resolution. The WSR-57 had pulse widths of about 2 km vs 250 m for the 88D and a beam width of about 2.2 degrees vs an average of ~ .92 degrees, for example. Therefore, at that time we emphasized a more "steady state" "single cell" structure for supercells. Both of those characteristics have since faded as a topic of discussion, unless it is to emphasize the departure of the storm in question from those characteristics. With higher resolution radars and visually, essentially all storms are multicellular. Every storm I have ever studied had some form of a multicellular structure. For this reason, the current storm classification system no longer deals with the numbers of cells. Les ************************ Leslie R. Lemon Radar, Severe Storms, & Research Meteorologist Tel. 816-373-3533, 816-213-3237 E-Mail: lrlemon at compuserve.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "Geelong Weather Services" To: Subject: RE: aus-wx: tornado climatology Date: Sat, 12 Aug 2000 11:04:18 +1000 X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com
In the words of my old professor, the renowned V. T. Shearenstein, (Norman, OK, circa 1970?) "If if looks like a tornado, if it acts like a tornado, if it sounds like a tornado and if it causes damage consistent with that of a tornado, the public is then entitled to call it a tornado." LS.
 X-Sender: nzts.nz at pop3.caverock.net.nz X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.3 (32) Date: Sat, 12 Aug 2000 13:35:34 +1200 To: aussie-weather at world.std.com From: John Gaul Subject: Re: aus-wx: STORM : Huntly Tornado - New Zealand Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com At 06:00 12/08/00 +1000, you wrote: >Hi John, > Were there any reports of hail? >- Paul G. Hello Paul G. There were no reports of hail with the tornado from what I gather from news reports. There was serious electrical activity in Taranaki with lightning killing a predoniment racehorse and cutting power to a lot areas from the same storm system. As usual, here in Christchurch we got bugger all from this weather system but the Southern Alps copped a bit of snow which made the ski-field operators quite happy John Gaul NZ Thunderstorm Society ____________________ >The Weather Company >Level 2, 7 West Street >North Sydney 2060 >Phone: (02) 9955 7704 >Fax: (02) 9955 1536 >twc at theweather.com.au >----- Original Message ----- >From: John Gaul >To: >Sent: Friday, August 11, 2000 1:47 PM >Subject: aus-wx: STORM : Huntly Tornado - New Zealand > > >> >> A tornado ripped through the Waikato town of Huntly in the North Island of >> New Zealand this morning at 7.30am NZ time damaging houses and generally >> making a bit of a mess in the town. >> Not to sure of other details but will let you know as they come to hand. >> >> >> >> John Gaul >> NZ Thunderstorm Society >> >> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com >> with "unsubscribe aussie-weather your_email_address" in the body of your >> message. >> -----------------------jacob at iinet.net.au------------------------------ > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ X-Sender: nzts.nz at pop3.caverock.net.nz X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.3 (32) Date: Sat, 12 Aug 2000 13:35:48 +1200 To: aussie-weather at world.std.com From: John Gaul Subject: Re: aus-wx: STORM: Re Huntly Tornado - New Zealand Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com At 00:30 12/08/00 +1000, you wrote: >Hi John and all > >I just found a report on the event from www.stuff.co.nz and it starts off >like this: >"A mini-tornado struck Huntly this morning tearing off several roofs, >downing power lines and uplifting trees." Hehehehe > >The rest of the report is here: >http://www.stuff.co.nz/inl/index/0,1008,310323a10,FF.html > Yes got that. Dumb press calling it a mini-tornado whereas the TV didn't. Here is the "NZ Herald" from Aucklands account of the mini-tornado TWISTER'S LASH WAKES HUNTLY 12.08.2000 - By MONIQUE DEVEREUX Phyllis Cartmill was making a cup of tea when she saw a bright flash of light and heard several loud bangs on her roof. Thinking her chimney had been hit by lightning in the thunder storm that was battering Huntly, she went into the lounge to investigate. "But, low and behold," said her son, Barry, "what she found was a gaping hole in the ceiling." Mrs Cartmill's roof had succumbed to a mini-tornado which swept through the town at 7.30 am yesterday. "Most of the front half of the roof had been ripped away and all the iron and whatnot was strewn around the garden and over the road," Mr Cartmill said. "Hell of a mess, really." Two people who were passing Mrs Cartmill's house on their way to work called in to check if she was all right and phoned the Fire Service. "She's just a bit shook up," Mr Cartmill said of his elderly mother. Directly across the river from Mrs Cartmill's house, the Taniwharau rugby league club also lost part of its roof. By mid-morning, a tarpaulin had covered most of the damage and one woman at the clubrooms said she was expecting the roof to be repaired by last night. Although she did not see the tornado, she pointed out its path. "See that barn up there on the hill? Well, that was a large barn. Now it's a quarter of a barn." Powerlines had been replaced and debris shifted from roads by yesterday afternoon. WEL Energy said the storm cut power to 1270 Huntly customers. MetService weather ambassador Bob McDavitt says the mini-tornadoes are caused by up- and down-drafts within the storm clouds, some which can reach 100 knots. The weather pattern that brought the thunder, lightning and mini-tornadoes from the Tasman Sea was expected to peak at 3 am today, he said. Regards John Gaul NZ Thunderstorm Society > >PS: For those at the ASWA AGM - Have a good one!! > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ X-Sender: nzts.nz at pop3.caverock.net.nz (Unverified) X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.3 (32) Date: Sat, 12 Aug 2000 13:49:11 +1200 To: aussie-weather at world.std.com From: John Gaul Subject: aus-wx: STORM: Lightning Kills Racehorse Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com For more on the Taranaki storms that killed a race-horse Read here http://www.stuff.co.nz/inl/index/0,1008,312109a1803,FF.html John Gaul NZ Thunderstorm Society NB> These are the same storms that produced the Huntly tornado +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ From: "bussie" To: Subject: Re: aus-wx: OFFTOPIC: Lightning hitting plane Date: Sat, 12 Aug 2000 15:42:41 +1000 X-Mailer: Microsoft Outlook Express 5.00.2615.200 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com That's unreal!!! I've never got my Video in the right place....... Bussy (NE Vic) ----- Original Message ----- From: Andrew Wall To: Sent: Wednesday, August 09, 2000 8:19 PM Subject: aus-wx: OFFTOPIC: Lightning hitting plane > Hi, > > I was just sent this link, some of you may be interested. > > http://lightning.pwr.eng.osaka-u.ac.jp/lrg/temp/plane.html > > regards > Andrew > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ X-Sender: paisley at mail.cobweb.com.au (Unverified) Date: Sat, 12 Aug 2000 18:51:37 +0930 To: aussie-weather at world.std.com From: Phil Bagust Subject: aus-wx: RE: SA page updates Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com A few recent snaps from South Australia at: http://www.cobweb.com.au/~paisley2/WeatherWX.html Also a copy of the 'Advertiser' Robe tornado article will be up soon. Cheers ___________________________________________________________________ Phil 'Paisley' Bagust - paisley at cobweb.com.au [Hm] - Philip.Bagust at unisa.edu.au [Wk] Paisley's Playpen at http://www.chariot.net.au/~paisley2 "Java = [J]ust [A]nother [V]irtual [A]nnoyance" +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------