X-Sender: nzts.nz at pop3.caverock.net.nz X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.3 (32) Date: Fri, 11 Aug 2000 00:22:38 +1200 To: aussie-weather at world.std.com From: John Gaul Subject: aus-wx: NEWSPAPER REPORTS: Heaven's Bounty Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Here's something that was reported in the Otago Daily Times this morning }Heaven's Bounty OTD - 10-8-2000 }London: It frequently rains cats and dogs in Britain, as any local will tell you, but Sunday }was different - it rained fish. }Britain's Meteorological Office said a shower of dead but still fresh sprats rained down on }the fishing port of Great Yarmouth, in the east England county of Norfolk, after a }thunderstorm. }Meteorological Office spokesman Sean Clarke said the fish shower would have been }caused by a small tornado out to sea, known as a waterspout. }It would have trawled up water and any fish near the surface. - Reuters Notice how the British press report it as a small tornado not mini Anyway there should be tornadoes galore across NZ western areas tomorrow as that rather large active looking trough moves across the country. The sattelite picture from MetService at 9pm NZ time looks good. Unfortunately, I don't think much will happen here in Christchurch. If there are any storm chasers in the North Island, I say to them to be alert and keep on their toes. There is some lightning flashing in the Southern Alps tonight but not as like what it was the other week unfortunately. John Gaul NZ Thunmderstorm 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------------------------------ X-Authentication-Warning: neumann.maths.monash.edu.au: robert owned process doing -bs Date: Thu, 10 Aug 2000 21:54:28 +1000 (EST) From: Robert Goler X-Sender: robert at neumann.maths.monash.edu.au To: Maillist Weather doods Subject: aus-wx: REPORT: Wollongong storm 01/08/00 - Illawarra Mercury article Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Perhaps people may have seen this already, but here's an article I came across in the Illawarra Mercury on 02/08/00. Perhaps the 11th paragraph may be interesting as it notes that residents in Corrimal and Bulli were reporting hail big enough to damage cars. Although the next paragraph says that minimal damage occurred. So, I guess this doesn't clear anything up. ----- Hail Chaos By Jodi Allen And Geoff Failes Illawarra Mercury A violent hailstorm, torrential rain and lightning strikes wreaked havoc with peak-hour road and rail movements in the Illawarra last night. The commuter chaos began just before 5pm, when plummeting temperatures on Mt Ousley turned heavy rain into hail. Hail and sleet reduced visibility on the F6 to a matter of metres, coating the road with a layer of sheet ice. Even moving at a snail's pace drivers reported having no control over their vehicles on the treacherous surface. Minutes after the storm hit a series of accidents forced traffic to a standstill. In one incident 10 vehicles were damaged and two people were taken to Wollongong Hospital with back injuries after a domino- effect collision, northbound at Cataract Creek. Traffic was backed up as far as Bulli Pass behind the accident scene. Police closed the F6, both north- and south-bound, for one hour, at first due to the accidents and then due to the hazardous road conditions. Traffic was diverted along Picton Rd and Bulli Pass. Things were no better for rail travellers who faced delays of up to 50 minutes after lightning strikes damaged signals between Bulli and Corrimal. Well before the Sydney weather bureau issued a 5.30pm severe thunderstorm warning for the greater Wollongong area, residents in Corrimal and Bulli were reporting hail stones large enough to damage cars. The State Emergency Service Illawarra-South division reported slight damage in the Corrimal area from the hailstorm. The spokeswoman said six calls for assistance were received, including one regarding damage to a roof, but three were later cancelled. ``The hail was about 10 inches deep in some places, we were told,'' she said. At the height of the storm Wollongong police were kept busy attending to flooded local roads and several traffic accidents. But the storm was nothing like the one that devastated southern Sydney in April last year. By 7pm the Bureau of Meteorology said the storm had moved out to sea and further severe weather was no longer expected, although some thunderstorms had been forecast for the Southern Highlands. Cheers -- Robert A. Goler E-mail robert at mail.maths.monash.edu.au http://www.maths.monash.edu.au/~robert/ Department of Mathematics and Statistics Monash University Clayton, Vic 3800 Australia -- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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: "Dean Sgarbossa" To: Subject: Re: aus-wx: tornado climatology Date: Thu, 10 Aug 2000 19:41:36 +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 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 To: Australian Severe Weather Association 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 >------------------------------------------- > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > 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: Re: aus-wx: Sunbury tornado spawned by supercell To: aussie-weather at world.std.com (Australian Severe Weather Association) Date: Thu, 10 Aug 2000 13:52:20 -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 Clyve, Hi aus-wx, Hamish and you mentioned weak shear values with the Sunbury storm. What data did you look at to estimate the "storm-felt" shear? At what time were those observations taken? I am particularly interested in the surface flow, the 850 hPa flow, and the hPa 500 flow. Severe storms forecasters in the US have been burned on occasion due to the *storm-relative* shear underestimation problem. The causes for this problem range from underestimating the relevance of the surface wind speed in computing a 0-6 km shear value, but most often "hidden" flow maxima or flow acceleration due to storm interaction, or storms that decide to do sharp turns. A famous example is the Jarrell (Texas) storm on 27 May 1997 which was a hard right mover in an environment of substantial CAPE and weak shear. Harald > Hi Hamish. > What a fantastic stroke of luck this whole event has been with what now > appears to have been a multiple tornadic episode across central Victoria, > that this Doppler apparatus was at that time in use. I agree that although > initially i suspected a severe multicell, the fact that a sustained updraft > (rotating) for almost one hour ,would most probably categorise this storm > system as a supercell ,possibly of the "winter" type with rather low > vertical extent . I believe the tops were between 28.000 and 32.000ft > although this is not yet confirmed, the 300hpa level was -50c not to bad, > again the lack of mid level shear appears to take some by surprise however > i now of other tornadic outbreaks here in Aus that have also occurred with > weak shear hope to here more regards Clyve Herbert. -- ------------------------------------------- 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------------------------------ From: "McDonald" To: Subject: aus-wx: Melbourne Doppler & storm warnings. Date: Thu, 10 Aug 2000 22:36:41 +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
Hey all,
 
This is just a quick email re: Melbourne's storms on Tuesday and the doppler radar.
 
Hamish's email has sparked some thought in my mind as to warnings for storms.  After the Syndey Hailstorm of 14th April 1999, there was significant uproar as to the BoM's warning systems.  I think the BoM was very lucky to escape unscathed (in terms of the media bringing up issues of warnings) for the Fairy Dell tornado as there was no warning issued at all if I remember correctly.  In Hamish's email, he stated that the doppler radar showed "good rotation in the main updraft for a period of about 50 minutes".  Please correct me if i'm wrong but in the US, this sort of information would result in a severe warning being issued for this particular storm when rotation inititated.  Their warnings include the direction of movement and the areas likely to be affected.  I'm not trying to have a go at the BoM here - I think with their current resources they did very well to issue warnings in as timely manner as they did.  I'm am worried that this technology is available and yet most capital cities in Australia do not have Doppler radars (to my knowledge) and those that do are merely used as an after-thought once these events have taken place.  Firstly, why not have a doppler installed in each capital city and secondly, why not use them to warn for events like this.  This raises some issues with the major one being cost.  I'm not entirely sure of the cost of each doppler unit but I know they stream well into the $millions and it could be very difficult to get any government body to spend big dollars on this technology (unless the inevitable happens - a strong tornado moves over a populated area resulting in the loss of life - and then watch them go for the wallet).  I know most people have seen the footage of the Sunbury tornado and some know that it has been officially rated as a strong F0/weak F1 with winds up to 150km/h.  I have been out and had a look at the damage to the basketball stadium and the houses in the outskirts of Sunbury and this area is far from a well populated area.  The potential was there for much more serious damage and injuries had the tornado been stronger or had it passed over a densely populated area.  I think that it is important to use the doppler resources we have in Melbourne and Sydney (and Brisbane?) as best as possible in working towards preventing the inevitable happening.  In my opinion, 50 minutes of rotation on the doppler meant that the people in Sunbury and surrounding areas in the path of the storm could've been warned 20 minutes or more in advance (estimate only) of the threat..........
 
End of thoughts for tonight....
 
Watch for report of damage track on the MSC page next week and check out the August reports page for information on the other tornadoes in Victoria on Tuesday (the count is up to 3 confirmed)....
 
 
 
Andrew McDonald
 
(Macca - MSC)
 
From: "clyve herbert" To: Subject: Re: aus-wx: tornado climatology Date: Fri, 11 Aug 2000 08:51:34 +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 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 To: 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 > To: Australian Severe Weather Association > 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 > >------------------------------------------- > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > > 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------------------------------ From: "David Findlay" To: Subject: RE: aus-wx: WEATHER DATA: All bom registered user data available free; was STORMS: Vic storms satpics! Date: Fri, 11 Aug 2000 08:34:16 +1000 X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 Importance: Normal Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com If they are going to release it, what's so hard about it. All they have to do is remove the passwords. David Findlay -----Original Message----- From: aussie-weather-approval at world.std.com [mailto:aussie-weather-approval at world.std.com]On Behalf Of Steve Summers Sent: Thursday, 10 August 2000 7:30 PM To: aussie-weather at world.std.com Subject: Re: aus-wx: WEATHER DATA: All bom registered user data available free; was STORMS: Vic storms satpics! ----- Original Message ----- From: David Findlay To: Sent: Thursday, August 10, 2000 8:35 AM Subject: RE: aus-wx: WEATHER DATA: Sorry I put my foot in my mouth. Sorry guys I let the cat out of the bag. Rang the person concerned with upgrading the Basic Product Set as I want to put some of the data on my weather page and happened to mention that it was freely available at this time using 'student' etc. They mentioned words like "breach of security" etc and I take it they have shut the gate. By the way I've been told by those in the know that this info will NOT be available until at least NOV. Cheers Steve > >I've just done a quick check on satpix, radar, models and data, and > >it's true -- this id/pw work with them all. > > Not any more. I just had a try but it doesn't work now! Maybe BOM cut it > off. > > David Findlay > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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: Melbourne Doppler & storm warnings To: aussie-weather at world.std.com (Australian Severe Weather Association) Date: Thu, 10 Aug 2000 18:26:20 -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 again from 35N 97W: Macca typed: > ... In Hamish's email, he stated that the = > doppler radar showed "good rotation in the main updraft for a period of = > about 50 minutes". Please correct me if i'm wrong but in the US, this = > sort of information would result in a severe warning being issued for = > this particular storm when rotation inititated. Their warnings include = > the direction of movement and the areas likely to be affected. I think most forecasters look at the combination of a persistent velocity couplet in the radar velocity data, a "good" reflectivity signature (hook, tight gradient) and a generally favourable storm environment before issuing a severe thunderstorm warning. Within some guidelines it is up to the individual forecaster. I think psychologically there is a big difference between issuing warnings for central Oklahoma (proven killer except for this year) and Melbourne (most liveable city). > ... I'm am worried that this technology is available and yet most = > capital cities in Australia do not have Doppler radars (to my knowledge) = > and those that do are merely used as an after-thought once these events = > have taken place. Firstly, why not have a doppler installed in each = > capital city and secondly, why not use them to warn for events like = > this. I hope/think that one fine day that will be the case. The operational 10 cm Doppler radar in the U.S. (WSR-88D) can be purchased for some 3-5 Mega Aussie dollars. Sydney has done this for the Olympics. On top of that there are other costs for training staff in using the accompanying software, maintenance and so on. > This raises some issues with the major one being cost. I'm not = > entirely sure of the cost of each doppler unit but I know they stream = > well into the $millions and it could be very difficult to get any = > government body to spend big dollars on this technology (unless the = > inevitable happens - a strong tornado moves over a populated area = > resulting in the loss of life - and then watch them go for the wallet). = It seems to work like this everywhere. The human causality much closer to disaster --> blame --> change --> radar than to change --> radar --> prevention --> less/no disaster. It is no secret that a number of my esteemed colleagues in the world of weather research wish for nothing more than a cat. 5 tropical cyclone parked over the White House... Cheers from 35N 97W, 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------------------------------ From: "clyve herbert" To: Subject: Re: aus-wx: Sunbury tornado spawned by supercell Date: Fri, 11 Aug 2000 09:05:04 +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 Hi Harald. Thanks for your reply, i have just completed a study into small weak tornado near Geelong in Jan this year, which occurred in a weak shear with no speeds greater than 29knotts throughout its depth.. When this was reported by Jane Oniell who videod the system the Mel BOM found it hard to believe as they said "but theres no shear" but there was good relative helicity and a strong low to mid level lapse rate I will make arrangements to sent you the report over the next 2 weeks. regards Clyve Herbert PS as an amateur the report cannot be official but the data and obs are interesting CH ----- Original Message ----- From: Harald Richter To: Australian Severe Weather Association Sent: Friday, August 11, 2000 4:52 AM Subject: Re: aus-wx: Sunbury tornado spawned by supercell > > Hi Clyve, Hi aus-wx, > > Hamish and you mentioned weak shear values with the Sunbury > storm. What data did you look at to estimate the > "storm-felt" shear? At what time were those observations > taken? I am particularly interested in the surface > flow, the 850 hPa flow, and the hPa 500 flow. > > Severe storms forecasters in the US have been burned on occasion due to > the *storm-relative* shear underestimation problem. The causes for this > problem range from underestimating the relevance of the surface > wind speed in computing a 0-6 km shear value, > but most often "hidden" flow maxima or flow acceleration > due to storm interaction, or storms that decide to do > sharp turns. A famous example is the Jarrell (Texas) > storm on 27 May 1997 which was a hard right mover in an environment of > substantial CAPE and weak shear. > > Harald > > > Hi Hamish. > > What a fantastic stroke of luck this whole event has been with what now > > appears to have been a multiple tornadic episode across central Victoria, > > that this Doppler apparatus was at that time in use. I agree that although > > initially i suspected a severe multicell, the fact that a sustained updraft > > (rotating) for almost one hour ,would most probably categorise this storm > > system as a supercell ,possibly of the "winter" type with rather low > > vertical extent . I believe the tops were between 28.000 and 32.000ft > > although this is not yet confirmed, the 300hpa level was -50c not to bad, > > again the lack of mid level shear appears to take some by surprise however > > i now of other tornadic outbreaks here in Aus that have also occurred with > > weak shear hope to here more regards Clyve Herbert. > > -- > ------------------------------------------- > 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------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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: "Michael Thompson" To: Subject: Re: aus-wx: End of Year Chase 2000 Date: Thu, 10 Aug 2000 18:41:21 +1000 Organization: X-Mailer: Microsoft Outlook Express 5.00.2014.211 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com
Thanks Dean. I have always maintained that it is only a matter of time ( and it may not be in the next 50 years ) before something bigger than a F3 rips through Sydney's west. Sadly I doubt we would be prepared.
 
Michael
 
----- Original Message -----
Sent: Wednesday, 9 August 2000 20:17
Subject: Re: aus-wx: End of Year Chase 2000

Hello Michael and all,
    I thought I would just shed some light concerning the topic of the End of Year Chase and the frequency of tornadoes in various parts of Australia. Perhaps the greatest hotspot for tornado occurrences is the Sydney Metropolitan Area itself. 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. Within a half circle with a radius of 50km around Sydney, a total of 6 tornadoes per year per 23,000 square kilometres occurred for the period 1960-1992. 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). Hereafter, Brisbane, Melbourne, Perth and Adelaide bare frequencies not lagging far behind that of Sydney.
    When you compare the frequency of tornado occurrences with that of the population density, the prominant reason why tornadoes are considered rare can be seen, (after Minor et al.)
    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. This is quite an extraordinary figure considering the population. If you compare this with Oklahoma in the US, which has a tornado occurrence of 22.0 per 100,000 square kilometres and a population density of 11.2 per square kilometre, the occurrence of tornadoes once joined with the density of population comes out to 2.0. This is a remarkable figure considering, just proving the point that in some cases, Australia is the home of tornado occurrences equal to, if not greater than that of the US is some areas.
    Other areas of significance are the Western Australia Agricultural Belt and Goldfields which has an tornado occurrence of 0.65, a population of 0.27 per square kilometre and the number of occurrence per 100,000 people is 2.4; still, quite a large number considering the population.The Victorian Western Highlands have a tornado occurrence of 5.6 and a population density of 5.6, leaving a rather small number of tornado occurrences per 100,000 people: 1.0. Finally the New South Wales Slopes have a tornado occurrence of 1.1, population density of 1.3 and an occurrence per 100,000 persons of just 0.9.
    However, using the figures of past tornado occurrences, the population of this ever-growing country proves a major dilemma and investigators problem when attempting to determine the climatology of Australian tornadoes. The large growth in population over the past decade (not taking into consideration environmental factors), the increase in population is single handedly responsible for the increase in tornado reports and hence, the frequency.
 
Cheers,
Dean AL Sgarbossa
 
-----Original Message-----
From: Michael Thompson <michaelt at ozemail.com.au>
To: aussie-weather at world.std.com <aussie-weather at world.std.com>
Date: Wednesday, 9 August 2000 19:03
Subject: Re: aus-wx: End of Year Chase 2000

>I think that the SE Queensland area north from Brisbane to say Bundaberg is
>one of Australia's tornado hotspots. Anybody have any idea on how many -
>Anthony, James ??
>
>Michael
>
>
>
>> My ears tweak to the sounds of 'Wide Bay'....we can all drop in at my
>> parents place in Maryborough and setup a new base and chase from there,
>> hehehe...wonder what they would say if I mentioned it to them,
>hmm....prolly
>> freak out :)
>>
>>
>> Mal.
>>
>> > ----------
>> > From: Michael Thompson[SMTP:michaelt at ozemail.com.au]
>> > Sent: Wednesday, 9 August 2000 10:22
>> > To: aussie-weather at world.std.com
>> > Subject: Re: aus-wx: End of Year Chase 2000
>> >
>> > Not sure on my chasing situation this year and probably won't know until
>a
>> > week or so out. I too share Clyve's thoughts about chasing SE
>Queensland.
>> > Gympie and the that area draw me, although terrain isn't chase friendly.
>> > Ideal situation would be to get a three day event starting in the
>Hunter,
>> > than onto the tablelands or Darling Downs, then over to the Wide Bay
>area.
>> >
>> > Such events have happened ! Perhaps a 4 day event for Clyve starting on
>> > the
>> > border of NSW/VIC
>> >
>> > Michael
>> >
>> >
>> > > Hi Jimmy and all.
>> > > I think the window period is as you said last week of Nov and first
>week
>> > of
>> > > Dec .Im not sure how many are coming from Vic I am trying to arrange
>> > about
>> > a
>> > > week at this time and i am looking forward to hitting the road
>although
>> > i
>> > > will be giving Thargominda a miss! Hopefully north east N.S.W and
>> > southeast
>> > > Q.L.D.will be firering up. regards Clyve.
>> > > ----- Original Message -----
>> >
>> >
>> >
>> >  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>> >  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
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>>  message.
>>  -----------------------jacob at iinet.net.au------------------------------
>>
>
>
> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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> -----------------------jacob at iinet.net.au------------------------------
>
X-Sender: paisley at mail.cobweb.com.au Date: Fri, 11 Aug 2000 10:01:45 +0930 To: aussie-weather at world.std.com From: Phil Bagust Subject: Re: aus-wx: tornado climatology Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com 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------------------------------ X-Originating-IP: [134.178.30.65] From: "hamish ramsay" To: aussie-weather at world.std.com Subject: aus-wx: Melbourne Doppler NOT operational. Date: Fri, 11 Aug 2000 01:39:34 GMT X-OriginalArrivalTime: 11 Aug 2000 01:39:34.0867 (UTC) FILETIME=[00D7DA30:01C00335] Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Andrew and others, please realise that the Doppler out at Broadmeadows is only in test mode at the moment and is not operational. This means that forecasters did not have Doppler data available at the time of the storm. It was only after the event that some of the severe weather researchers had time to put the data together and do a careful analysis of the event. With this in mind, I think forecasters at the time handled the situation very well. I am not sure when Melbourne will be using Doppler operationally. -Hamish. >From: "McDonald" >Reply-To: aussie-weather at world.std.com >To: >Subject: aus-wx: Melbourne Doppler & storm warnings. >Date: Thu, 10 Aug 2000 22:36:41 +1000 > >Hey all, > >This is just a quick email re: Melbourne's storms on Tuesday and the >doppler radar. > >Hamish's email has sparked some thought in my mind as to warnings for >storms. After the Syndey Hailstorm of 14th April 1999, there was >significant uproar as to the BoM's warning systems. I think the BoM was >very lucky to escape unscathed (in terms of the media bringing up issues of >warnings) for the Fairy Dell tornado as there was no warning issued at all >if I remember correctly. In Hamish's email, he stated that the doppler >radar showed "good rotation in the main updraft for a period of about 50 >minutes". Please correct me if i'm wrong but in the US, this sort of >information would result in a severe warning being issued for this >particular storm when rotation inititated. Their warnings include the >direction of movement and the areas likely to be affected. I'm not trying >to have a go at the BoM here - I think with their current resources they >did very well to issue warnings in as timely manner as they did. I'm am >worried that this technology is available and yet most capital cities in >Australia do not have Doppler radars (to my knowledge) and those that do >are merely used as an after-thought once these events have taken place. >Firstly, why not have a doppler installed in each capital city and >secondly, why not use them to warn for events like this. This raises some >issues with the major one being cost. I'm not entirely sure of the cost of >each doppler unit but I know they stream well into the $millions and it >could be very difficult to get any government body to spend big dollars on >this technology (unless the inevitable happens - a strong tornado moves >over a populated area resulting in the loss of life - and then watch them >go for the wallet). I know most people have seen the footage of the >Sunbury tornado and some know that it has been officially rated as a strong >F0/weak F1 with winds up to 150km/h. I have been out and had a look at the >damage to the basketball stadium and the houses in the outskirts of Sunbury >and this area is far from a well populated area. The potential was there >for much more serious damage and injuries had the tornado been stronger or >had it passed over a densely populated area. I think that it is important >to use the doppler resources we have in Melbourne and Sydney (and >Brisbane?) as best as possible in working towards preventing the inevitable >happening. In my opinion, 50 minutes of rotation on the doppler meant that >the people in Sunbury and surrounding areas in the path of the storm >could've been warned 20 minutes or more in advance (estimate only) of the >threat.......... > >End of thoughts for tonight.... > >Watch for report of damage track on the MSC page next week and check out >the August reports page for information on the other tornadoes in Victoria >on Tuesday (the count is up to 3 confirmed).... > >http://www.stormchasers.au.com/august2000.htm > > >Andrew McDonald > >(Macca - MSC) > ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.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------------------------------ X-Sender: nzts.nz at pop3.caverock.net.nz (Unverified) X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.3 (32) Date: Fri, 11 Aug 2000 15:47:02 +1200 To: aussie-weather at world.std.com From: John Gaul Subject: aus-wx: STORM : Huntly Tornado - New Zealand Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com 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------------------------------ 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 00:46:24 +1200 To: aussie-weather at world.std.com From: John Gaul Subject: aus-wx: STORM: Re Huntly Tornado - New Zealand Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com 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. The scenario did look very good on satellite imagery, thats why I predicted that we would get possibly some tornadoes in my email last night. 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------------------------------