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Australian Weather Mailing List Archives: 4th January 1999 |
From Subject
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001 wbc at ozemail.com.au (Laurier Williams) Grafton receives heavy rain.
002 "Jane ONeill" [cadence at rubix.com.au] Darwin report
003 Phil Bagust [mail.cobweb.com.au at redback.cobwe Atypical Storms
004 Blair Trewin [blair at met.Unimelb.EDU.AU] Hi All
005 Michael Scollay [michael.scollay at telstra.com. SE Qld heavy rain: 228mm at Natural Bridge
006 Blair Trewin [blair at met.Unimelb.EDU.AU] NE Victoria as a potential storm-chasing venue
007 Ben Quinn [bodie at corplink.com.au] Assesing the Potential for Severe wx
008 Michael Scollay [michael.scollay at telstra.com. Bass Strait Low
009 "Andrew Treloar" [pileus at hotmail.com] Hi All
010 "Terry Bishop" [dymprog at mpx.com.au] Orange AWS
011 "Terry Bishop" [dymprog at mpx.com.au] Re Orange AWS
012 mildad [mildad at one.net.au] (no subject)
013 Michael Scollay [michael.scollay at telstra.com. Media Communication of Severe Thunderstorms.
014 Michael Scollay [michael.scollay at telstra.com. Media Communication Of Servere Thunderstorms
015 Duane Van Schoonhoven [vanscho at ozemail.com.au Orange AWS
016 Local_Court_Maclean at agd.nsw.gov.au Venue for ASWA meeting on Sat 9.1.99
017 Michael Scollay [michael.scollay at telstra.com. East Coast Lows.
018 Michael Scollay [michael.scollay at telstra.com. Media Communication of Severe Thunderstorms.
019 Local_Court_Maclean at agd.nsw.gov.au East Coast Lows.
020 Michael Scollay [michael.scollay at telstra.com. Media Communication of Severe Thunderstorms.
021 Blair Trewin [blair at met.Unimelb.EDU.AU] Very hot in SE Australia - except on the coast
022 Michael Scollay [michael.scollay at telstra.com. Potential hot weather in Melbourne
023 mildad [mildad at one.net.au] (no subject)
024 Michael Scollay [michael.scollay at telstra.com. Web Photos
025 Jimmy Deguara [jimmyd at ozemail.com.au] Lifted Index charts
026 Paul Graham [pgraham1 at mail.usyd.edu.au] Thickness and Temperature...
027 "Michael Thompson" [michaelt at ozemail.com.au] Atypical Storms
028 "James Chambers" [jamestorm at ozemail.com.au] SA Thunderstorms
029 "Michael Thompson" [michaelt at ozemail.com.au] Atypical Storms
030 wbc at ozemail.com.au (Laurier Williams) Orange AWS
031 Phil Bagust [mail.cobweb.com.au at redback.cobwe Adelaide firing up!
032 "Mark Hardy" [mhardy at nsw.bigpond.net.au] Thickness and Temperature...
033 Phil Bagust [mail.cobweb.com.au at redback.cobwe Assesing the Potential for Severe wx
034 Phil Bagust [mail.cobweb.com.au at redback.cobwe SA severe storms
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001
From: wbc at ozemail.com.au (Laurier Williams)
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Grafton receives heavy rain.
Date: Sun, 03 Jan 1999 14:12:01 GMT
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On Thu, 24 Dec 1998 11:48:31 +1000, Local_Court_Maclean at agd.nsw.gov.au
wrote:
>Good heavy falls received in the Grafton areas, from 3pm 23.12 til 9am
>24.12 Grafton received 100mm!! Its a bit wet they tell me, and alot of
>minor flooding around the place.
>
>The Locals say that in the hills to the west, alot more was received (some
>are talking about 10 inches!!)
>
>The BOm only has a AWS in Grafton so it would interesting to see some info
>come in!
>
Hi everyone. I'm gradually wading through about 350 aussie-weather
messages that came in after I got back online just after Christmas,
and have just found this one. Apologies to all if it's already been
followed up, but I haven't come across a response yet, and it deserves
one!
The heaviest rain totals I've found were in the upper Tweed catchment
on the NSW/Qld border. Uki, about 10km SW of Murwillumbah, recorded
366mm for the 24 hours to 9am 24/12/98, with 403mm falling in the full
rain event over 19 hours between 10pm 23/12/98 and 5pm 24/12/98.
152mm fell in 60 minutes to 3.17am! This has a return period >100
years. But so does the second downpour, which gave 205mm in 3 hours to
7.35am. When you combine these into the maximum 6 hourly total of
360mm to 7.45am, it must go off the scale!
The hourly readings from the BoM Uki gauge were:
2-3am 146mm
3-4 8mm
4-5 14mm
5-6 68mm
6-7 98mm
7-8 25mm
Glengaven, just across the border in Qld, and NW of Murwillumbah,
reported 227.6 for the 24 hours to 9am 24/12/98, and other totals were
184 at Brays Creek, 156 at Bald Mountain and 136 at Doon Doon. All
these are W or SW of Murwillumbah.
Murwillumbah's Bray Park climatalogical station recorded only 50.8mm
-- and it is only about 10km away from Uki, so the falls were
localised, but still spread in an arc around the upper valley from SW
to nearly N of Murwillumbah..
With the exception of Bray Park and Glengaven, the rest are
telemetered Bureau raingauges. The quantum of the falls, the timing of
the heavy hourly falls, and the reported flash flooding do suggest
they are credible. It will be interesting to watch the confirming
returns come in from the observers.
--
Laurier Williams
Australian Weather Links and News
http://www.ozemail.com.au/~wbc/
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002
From: "Jane ONeill" [cadence at rubix.com.au]
To: "Aussie Weather" [aussie-weather at world.std.com]
Subject: aussie-weather: Darwin report
Date: Mon, 4 Jan 1999 08:03:31 +1100
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Well, back from Darwin to Melbourne and back to work!!
Arrived up north late on 27th December, couple of active cells at the
southern margin of the Top End, ... absolutely nothing around Darwin.
Monsoonal trough hung around for much of the week I was there, localised
showers on and off with virtually no electrical activity until the night of
the 2nd Jan when Palmerston had 3 small and not particularly active cells to
the east, south and south west (but at least I can say that I heard thunder
and saw lightning!! ). Humpty Doo had a couple of good showers earlier in
the week (2"). Far more humid than at the same time last year, but a
significant drop in storm activity. Nice to catch up with old friends, but
the video didn't get a workout :(. Didn't miss anything guys.
Melbourne this morning - 17.6, 8/8, Sc. Forecasting 29 & storms on the
eastern ranges.......
Jane
Melbourne
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003
X-Sender: paisley at mail.cobweb.com.au
Date: Mon, 4 Jan 1999 08:05:30 +0930
To: aussie-weather at world.std.com
From: Phil Bagust [mail.cobweb.com.au at redback.cobweb.com.au]
Subject: Re: aussie-weather: Atypical Storms
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
>Take a look at this page for information on atypical storm types:
>
>http://www.nssl.noaa.gov/swat/Cases/cases_pix.html
>
>Sam Barricklow
I urge people to do just that. It's a fascinating set of pages and images.
what struck me was the variety of beasties that can produce rotating mesos.
Low topped supercells I'd heard of, but mini-supercells are a new one to me.
What seems to be consistent (although I've only scratched the surface here)
is that shear is just as, if not more important than instability in
producing rotating systems. Some of those mini-supercells seemed like they
might have been quite unimpressive visually - yet they still produced
tornados!
The other thing is the Australian aspect. How closely do US thunderstorm
morphologies match ours? I know I've seen comments from (Michael Bath?)
suggesting that most Australian mesos are spawned by classic HP supercells
but has there been any serious work done on the various animals in our zoo?
What about non-supercell clouds that drop 'landspouts' (ie Cleve SA 1992)??
Does anybody know of any web articles that adress these issues in an
Australian context? Can I get a debate started here?? In the absense of
ANY INSTABILITY AT ALL in dear old Adelaide - I wait with baited breath....
--------------------------------------------------------------------------------------
004
From: Blair Trewin [blair at met.Unimelb.EDU.AU]
Subject: Re: aussie-weather: Hi All
To: aussie-weather at world.std.com
Date: Mon, 4 Jan 1999 11:14:24 +1100 (EST)
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Terry Bishop wrote:
(snip)
> Anybody who checks the official temps and rainfall for Orange. These
> readings are taken on a AWS at Orange airport.
> This is situated about 12K's SE of Orange. The terrain there is flat and
> open. Their wind, temps and rainfall patterns are different to that of the
> hillier built up city. The airport is more effected on the Westerly stream
> by the large Mount Canoblas which is about 300 Metres above the surrounding.
> terrain. There are also a lot of orchards between Canoblas and the airport.
> All with their large dams and constant irrigation that must have some effect
> on the rainfall/humidity patterns. We seem to get most of our rain from the
> SW (from Canoblas) but W is usually the prevailing wind so the Airport
> usually gets more rain than the city.
>
> My readings are taken from 1.5K's SE of the Post Office in the built up
> area. I find the town usually is cooler in the summer and warmer in the
> winter than the airport especially winter minimums. I don't know why the BoM
> can't standardise and put all AWS's say at the Post Office which is usually
> near the centre of most town/cities.
For this very reason - because the post office is at the centre of
most towns/cities, and is therefore (a) affected by being in the
centre of the urban heat island in general (and even a town of Orange's
size will have one, although they can be masked by topography) and
(b) being very prone to being built out. Quite often 'Post Office'
sites are actually on a vacant lot near the post office - but these
have a nasty habit of turning into asphalt car parks or the like,
which makes a real mess of the temperature record. (I know of one
NSW site where the council built an incinerator a few metres from the
screen!). Rainfall is even worse, as it is very hard to find a town
centre site (or a suburban backyard one for that matter) which meets
the standard (all obstructions must be at least twice as far away as
they are high, e.g. a 5m building must be no closer than 10m to the
gauge).
An airport site has a far better chance of staying stable in the long
term than a town centre one does (the same applies to other out-of-town
sites - agricultural research stations, lighthouses etc.). I believe
it is long-term Bureau policy to phase out PO sites, although I've
never seen this written down anywhere. In this day and age, POs also
suffer from a reluctance to take weekend observations (although that
isn't an issue with an AWS).
The problem at Orange is that the topography is such that the airport
isn't particularly representative of the climate in the town area,
something quite rare for an Australian town (partly because most town
areas are flatter, partly because Orange airport is a long way out
of town). Ballarat has a similar problem. The Orange observing site
has been at the airport since 1969, so from the climate point of view
a move back to the town area (either the centre or a 'parkland' site)
would be a major discontinuity - although Orange isn't used for much
climate work because of the proximity of the excellent Bathurst Ag.
Research site.
As an aside, I wouldn't mind a dollar for every time that I've seen
an item of correspondence in a station file from a local council
lobbying the Bureau to move their instrument site to somewhere warmer
- Inverell, Ballarat and Ararat are particularly persistent in this
regard. (The Ballarat council's refusal to accept that Ballarat is a
cold place was so persistent that I, had I been on the end of their
letters, would have been sorely tempted to tell them to go and put
their thermometers somewhere where it's always 37 degrees...).
Blair Trewin
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005
Date: Mon, 04 Jan 1999 11:13:01 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: SE Qld heavy rain: 228mm at Natural Bridge
Sender: aussie-weather-approval at world.std.com
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James Chambers wrote:
> ...
> The highest falls included Natural Bridge 228mm, Nerang...
I'm back with 400+ Emails to read...
We have friends who live in the Numimbah Valley who reported that the
road to Natural Bridge was closed by flash flooding and the pathways
later found damaged (washed away in parts) on the way to -that-
beautiful waterfall at Natural Bridge.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
006
From: Blair Trewin [blair at met.Unimelb.EDU.AU]
Subject: aussie-weather: NE Victoria as a potential storm-chasing venue
To: aussie-weather at world.std.com (Aussie Weather)
Date: Mon, 4 Jan 1999 11:19:19 +1100 (EST)
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(I'm responding here to those who were suggesting going to Albury
as a base for a chase - I can't find the exact message).
The eastern ranges of Victoria (i.e. east of the Hume Highway) are
not really promising chase country - the terrain gets mountainous
fairly quickly and the road network is sparse.
On the other hand, northern Victoria west of the Hume would be
excellent - flat and open, so you can see more or less forever, and
a good road network (a grid in many places, which makes navigation
a bit easier). Unfortunately, the frequency of storm activity on
the plains isn't as great as it is on the mountains. Thursday looks
as if it has potential, though.
Blair Trewin
--------------------------------------------------------------------------------------
007
Date: Mon, 04 Jan 1999 10:40:41 +1100
From: Ben Quinn [bodie at corplink.com.au]
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Assesing the Potential for Severe wx
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
>I urge people to do just that. It's a fascinating set of pages and images.
>what struck me was the variety of beasties that can produce rotating mesos.
>
>Low topped supercells I'd heard of, but mini-supercells are a new one to me.
>What seems to be consistent (although I've only scratched the surface here)
>is that shear is just as, if not more important than instability in
>producing rotating systems. Some of those mini-supercells seemed like they
>might have been quite unimpressive visually - yet they still produced
>tornados!
>
>The other thing is the Australian aspect. How closely do US thunderstorm
>morphologies match ours? I know I've seen comments from (Michael Bath?)
>suggesting that most Australian mesos are spawned by classic HP supercells
>but has there been any serious work done on the various animals in our zoo?
>What about non-supercell clouds that drop 'landspouts' (ie Cleve SA 1992)??
>
>Does anybody know of any web articles that adress these issues in an
>Australian context? Can I get a debate started here?? In the absense of
>ANY INSTABILITY AT ALL in dear old Adelaide - I wait with baited breath....
>
Hey Ben from Brisbane here
Of course instability plays a large role, but I would say that Shear (and
other factors) plays an almost crucial role in the development of rotating
sytems. And there are easy ways to asses the amount of shear in the
atmosphere. I will guide you through this process, i highly recomend
everyone does this, as once you get the hang of it you'll be forecasting
severe weather like the pro's :)
If you go to this page you can access Atmospheric Soundings for all the
capital cities in Australaia (some cities are not available at night: 12z)
and some regional centres:
http://www-das.uwyo.edu/upperair/au.html
First off you will see three options (Text : Gif : Postscript) , choose
"Text".
The type of thermodynamic diagram to plot is not applicable in this case
(but normally it would be Skew-T).
Now, select the latest sounding time available (Lately the site has been
having troubles updating, i have emailed the webmaster and i was told
they were having software problems, and it should be back to normal soon)
Now select a station closest to you (if you click on the station and you
get a "no data available error" then you will have to type the station id
in manually in the "Station ID" box, and press "Submit Request")
A text version of an atmospheric soundings for the time and station you
selected should appear on screen. Now what the hell does all that mean
you say? Dont be scared off, this is where this page comes in:
http://www.nemas.net/edu/soundings/soundings.htm
On the sounding, dont worry about all the numbers at the top of the page,
scroll down past these until you reach "Sounding variables and Indicies".
The above page gives an explanation of most Variable and Indicies, you
can simply have it in another window and refer to it as you read the
soundings.
Take note of the following Indicies, "Storm Relative Helicity" "Bulk
Richardson Number" "Energy-Hel Index" and "Bulk Richardson Shear" at the
bottom of the page in the Wind Parameters section (Also "Shear" is an
important one, although most of the above Indicies are generally
calcualted with the shear values in mind). There are also some generall
figures to go by in the Description of these indicies.
These are all great indications of the potential for severe/mesocyclonic
thunderstorm development. In allot of case studies you will see these
Indicies and others refered to.
The other indicies such as "Lifted Index" "Shoalwater Index" "Total
Totals" "Sweat Index" the "Energy Index" and of course "CAPE" are
all pretty much Instability Indicies, Obviously the higher (or in some
cases the lower) the value the greater potential for severe convection
to occur.
If anyone has any questions/problems dont hesitate to contact me at
Bodie at corplink.com.au and i will gladly answer any question.
l8tr
www.nemas.net/edu/index.htm
--------------------------------------------------------------------------------------
008
Date: Mon, 04 Jan 1999 12:19:31 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Bass Strait Low
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Paul Graham wrote:
>
> Reports on ABC radio that the cool change has brought summer snow falls to
> the higher parts of the Snowy Mtns and the Victorian Alps...
Reports from Perisher Valley on that day will be published in the
Technology Ski Club monthly newspaper later this month. They have
pictures of a very good fall of snow somthing like 30cm+. If I get a
copy, I'll send it to Jimmy or Michael for publishing on the web.
Michael Scollay mailto:michael.scollay at telstra.com.au
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009
X-Originating-Ip: [134.178.120.10]
From: "Andrew Treloar" [pileus at hotmail.com]
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Hi All
Date: Sun, 03 Jan 1999 17:35:58 PST
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
>Terry Bishop wrote:
>> I don't know why the BoM
>> can't standardise and put all AWS's say at the Post Office which is
usually
>> near the centre of most town/cities.
Blair Trewin Replied
>An airport site has a far better chance of staying stable in the long
>term than a town centre one does (the same applies to other out-of-town
>sites - agricultural research stations, lighthouses etc.). I believe
>it is long-term Bureau policy to phase out PO sites, although I've
>never seen this written down anywhere. In this day and age, POs also
>suffer from a reluctance to take weekend observations (although that
>isn't an issue with an AWS).
>
One of the main reasons for AWS being situated at airports is the
Bureau's role in forecasting for aviation, with a need for hourly
details at the areodrome. Also the aviation industry provides a fair
amount of the money to the Bureau for the instalation of AWS's, so it is
only fair that they go where they want them.
Also as Blair pointed out, maintaining the integrity of the observation
site is a lot easier at an airport.
--------------------------------------------------------------------------------------
010
From: "Terry Bishop" [dymprog at mpx.com.au]
To: "Aussie-weather" [aussie-weather at world.std.com]
Subject: aussie-weather: Orange AWS
Date: Mon, 4 Jan 1999 12:47:40 +1100
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Hi Blair,
Thanks for responding to my thoughts re Orange AWS. I can see you point of
view re reflective heat ect when in town.
I feel if they could move the AWS to another site such as our Dept. Ag.
Research station which is situated on the Southern edge of town or the
Orange Ag. college which is a branch of the Uni. of Sydney situated on the
Northern edge of town the recording would be more representive of the City
of Orange climate.
I was thinking of the Dept. Ag. state head office but they also have
concrete everywhere so again reflective heat would be a problem.
I don't know what Ballarat is going on about. Orange is not a cold climate
either with a nice crisp -7C to 2C in winter. Like everywhere else like the
Snowys it's not as cold as it used to be. I can remember as a young lad
scrapping ice off the car windscreen in late March. Now, for quite a few
years we have not had our first decent frost till well after Anzac day. I
used to have to shovel the snow drifts from our back screen door so we could
push it open. Orange has not had snow of that quantity for a long time.
Regards Terry.
--------------------------------------------------------------------------------------
011
From: "Terry Bishop" [dymprog at mpx.com.au]
To: "Aussie-weather" [aussie-weather at world.std.com]
Subject: aussie-weather: Re Orange AWS
Date: Mon, 4 Jan 1999 13:00:28 +1100
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Hi Andrew T,
I have just sent my reply of to Blair before I read your letter.
I did not realise that the aviation industry helped out with the monetary
side of things. That changes the complexion of things. Thanks for advising
me of the facts. I will be a lot happier when I know ALL the facts re
weather if that is possible.
Regards Terry.
--------------------------------------------------------------------------------------
012
Subject: aussie-weather: Re: NE Victoria as a potential storm-chasing venue
Date: Mon, 4 Jan 99 14:06:34 +1000
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> Unfortunately, the frequency of storm activity on
>the plains isn't as great as it is on the mountains. Thursday looks
>as if it has potential, though.
Thanks for that info Blair. We were going to base ourselves at Albury and
then head towards Bendigo; coming from Sydney I guess Albury is more or
less the gateway to the Victorian plains where, a few days out, that is
the area which looked as though it might fire - the road network is also
fantastic, something we lack in most of NSW. Anyway, as it turns out, the
activity was east and into the highlands so we would not have been able
to chase far in anycase.
One thing about that region (plains) of Victoria is that although the
frequency of storms is not all that great by our east coast standards, it
does see some very significant storms - by my GUESStimation probably the
highest relative proportion of supercells (ie supercells / total storm
activity) in any part of Australia.
David
--------------------------------------------------------------------------------------
013
Date: Mon, 04 Jan 1999 14:35:14 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m)
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Media Communication of Severe Thunderstorms.
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Paul_Mossman at agd.nsw.gov.au wrote:
> ...Crap, crap, crap.................
Agree, agree, agree.................
The cynic in my thoughts reckons that the media would have a active
interest in crappy weather warnings or none at all because there's
"nothing quite like a good story of death, destruction, doom and
gloom".
Now to change that around so that proper warnings get out in a timely
manner...
(1) A siren with variable tones just like the ones in WW2 air-raid
warnings e.g. one for fire, another for thunderstorms etc. That's just
an idea. One tone would do.
(2) An automagic radio station that locals can tune to for details
about the nature of the alert.
(3) Other alert advice e.g. GSM short message service on active mobile
phones etc.
(4) Simultaneous alert advice to media interests.
Notice how the media is only fourth in the above priority. Clearly,
some media have failed to exercise appropriate public interest in the
proper and timely broadcast of severe weather advice. Therefore, an
alternative and more reliable means is required.
Unfortunately, it's only after severe damage or death do authorities
act in any way to prevent future loss. Basically, action only happens
while the disaster-effects are fresh in the public memory and would
enhance the sitting member's re-election prospects.
To make a national case out of this would require the compilation of a
cost / benefit analysis scenario.
ASWA could assist and initiate, but not drive such a process.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
014
Date: Mon, 04 Jan 1999 15:00:23 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Media Communication Of Servere Thunderstorms
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
2KY Racing Radio wrote:
>
> Hello all,
>
> Let me start off by saying that these views do not reflect the management or
> staff here at 2KY, just my own...
It was great to read and agree with these views of Grant. Please see
my reply to Paul's mail suggesting alternative means of alert
distribution. Clearly, there is a problem getting severe weather
alerts to the media in a timely manner and this needs to solved
immediately, perhaps investigated formally and reported politically in
the light of two recent events (one which will have an formal enquiry
initiated) which claimed lives and property. Alternative severe
weather alert means suggested will take more time.
But the quintessential point raised is that to maximise the
dissemmination of timely severe weather alert information requires the
availability of real-time BoM services such as radar with its proper
interpretation to as many distribution points as possible. I think
that the minister ultimately responsible needs to be lobbied to make
such services available for free in view of the public safety service
it clearly provides.
I believe there is the making of a reasonable case in the above that
is worth presenting in a form to local MHR's (Members of the House of
Representatives). I think the ASWA could take an active role in
formulating such a submission on behalf of interested parties and the
public at large.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
015
Date: Mon, 04 Jan 1999 14:42:12 +1030
From: Duane Van Schoonhoven [vanscho at ozemail.com.au]
X-Mailer: Mozilla 4.5 [en] (Win95; I)
X-Accept-Language: en
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Orange AWS
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
G'Day All,
Sorry, I couldn't resist....
"And walk to school and home again, in the snow, uphill, both ways!" : )
Cheers,
Duane Van Schoonhoven
Paracombe, SA
Terry Bishop wrote:
> ....Snip.... Like everywhere else like the
> Snowys it's not as cold as it used to be. I can remember as a young lad
> scrapping ice off the car windscreen in late March. Now, for quite a few
> years we have not had our first decent frost till well after Anzac day. I
> used to have to shovel the snow drifts from our back screen door so we could
> push it open....Snip....
--------------------------------------------------------------------------------------
016
From: Local_Court_Maclean at agd.nsw.gov.au
X-Lotus-Fromdomain: NSW_AG
To: aussie-weather at world.std.com
Date: Mon, 4 Jan 1999 15:25:24 +1000
Subject: aussie-weather: Venue for ASWA meeting on Sat 9.1.99
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Howdy. I was just wondering whether there is a venue set yet for the
meeting? Thax guys.
Paul.
--------------------------------------------------------------------------------------
017
Date: Mon, 04 Jan 1999 15:45:53 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m)
X-Accept-Language: en
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: East Coast Lows.
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Phil Bagust wrote:
>
> >Paul G makes a very interesting and valid point with reagrds to a possible
> >ctaegory for these South Ocean Lows or even east Coast Lows. They are
> >cyclones lets face it - just Cold centred rather then warm centred. The BOM
> >could put a warning that say a Cat 2 Southern Low will form and have winds
> >gusting to....and the areas that may experience weather form that Low. Good
> >Point Paul G.
>
> I may be hallucinating, but I'm sure I read somewhere that at least some
> east coast lows were warm centred, which might account for their intense
> winds and rain, compact size and 'look' on satellite photos.
This subject warrants some more discussion suffice to say that some of
the world's most intense "lows" form around the Antartic and Artic
regions perhaps more frequently and reliably as their tropical
cousins. This discussion of cyclones only belonging to the tropical
regions is technically bumkum, just ask those poor sailors dealing
with these systems staking their lives as their only collateral in
Bass Straight and the Southern Ocean.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
018
Date: Mon, 04 Jan 1999 16:05:24 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m)
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Media Communication of Severe Thunderstorms.
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Andrew Treloar wrote:
> ... Following the Yamba-Byron Bay storm we asked people to ring us
> with information on the storm. Of the 2 dozen or so people who took
> the time to do that, about 20% had heard the advice.
Thanks Andrew. That's not bad coverage considering that those who
heard the warnings would also be listening for reports and/or feedback
after the event. The trick is to get the warning to the majority of
people who don't have their radio or TV turned on.
Have the Bom got any ideas about improving the coverage to the vast
majority including more precise forecasts of approaching severe cells
to particular towns and/or districts?
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
019
From: Local_Court_Maclean at agd.nsw.gov.au
X-Lotus-Fromdomain: NSW_AG
To: aussie-weather at world.std.com
Date: Mon, 4 Jan 1999 16:04:41 +1000
Subject: Re: aussie-weather: East Coast Lows.
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
I hate to be a fiddler for things but I actually wrote that Michael, not
Phil.
Paul Mossman.,
--------------------------------------------------------------------------------------
020
Date: Mon, 04 Jan 1999 16:21:01 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m)
X-Accept-Language: en
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Media Communication of Severe Thunderstorms.
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Paul Graham wrote:
>
> Hi Andrew and everyone,
> In a previous message to this list (a couple of months ago -
> archive on Michael B's australiansevereweather.simplenet.com) I mentioned
> the possibility of setting up a radio network specifically for storm
> warnings (like the NOAA weather radio in the US). Do you think this
> would be feasible? This would allow a continuous update of the storm
> situation rather than having to wait for a local radio station which may
> only broadcast the warning once in the advice period.
> My idea would be to have a scattering of MW or HF AM radio
> stations for this purpose - I believe the US NOAA weather radio is only
> available to those with the right type of receiver (I think it's on VHF).
> Such a network should be as widely accessible as possible, so ideally you
> would want to be able to receive it on a normal AM/FM car radio.
> What do you think of these ideas?
> - Paul G.
It's ultimately one of the ways to go as is something like using GSM
Short Message Service on every carrier's mobile network but somehow
you must be able to reach the masses who arn't tuned-in or turned-on.
As a kid, I can remember the siren going off to call in the
fire-fighters around Katoomba when the upper Blue Mountains blew up
burning down 60+ houses near Bullaburra. There's not a person with
working ears who did not hear that or realise what it was signifying.
There's an opportunity here to broaden the scope of such community
alert devices, but only with the aid of real-time severe weather
information.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
021
From: Blair Trewin [blair at met.Unimelb.EDU.AU]
Subject: aussie-weather: Very hot in SE Australia - except on the coast
To: aussie-weather at world.std.com (Aussie Weather)
Date: Mon, 4 Jan 1999 16:50:34 +1100 (EST)
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Widespread 40+ today in inland SE Australia - 44 at sundry SA locations
(Tarcoola, Ceduna, Polda Basin, Port Augusta) is the highest I've seen,
but plenty of 42/43 scattered through SA, northern Victoria and southern
NSW.
Very sharp temperature gradient near the Victorian coast - Ballarat
(34) was 10 degrees hotter than Melbourne (24), which you don't see
too often.
If the change stalls Wednesday in Melbourne could be very hot indeed.
I wouldn't be surprised to see 42-43 if the change is late enough.
Blair Trewin
--------------------------------------------------------------------------------------
022
Date: Mon, 04 Jan 1999 17:14:12 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m)
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To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Potential hot weather in Melbourne
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Blair Trewin wrote:
>
> All the models are suggesting some seriously warm weather in
> Melbourne in the first half of next week - thicknesses Monday/Tuesday
> next week peak around 574-579, depending on the model - this could
> well mean close to or over 40.
Is there a correllation / formulae / tables / rule-of-thumb that
relates 500-1000mb thickness to temperature at particular altitudes
e.g. 1000mb, 850mb etc.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
023
Subject: Re: aussie-weather: Atypical Storms
Date: Mon, 4 Jan 99 17:31:24 +1000
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Hi to Phil and everyone
That page is interesting (thanks Sam). There was actually a chase report
with pictures ( similar to those at
http://hesston.spc.noaa.gov/~mkay/may28/ ), I think on the SCH, of one of
the 'mini supercells'. Cant remember the chaser or location but I can
remember it certainly was pretty amazing stuff.
>The other thing is the Australian aspect. How closely do US thunderstorm
>morphologies match ours?
I presume that all the different supercell (and other storm) types that
occur in the US would also occur in Australia although I have never seen
a picture of an LP supercell here. Since I began reading up on it, the
sub-classification of supercells has always interested me although the
actual boundaries can be a bit arbitray since it is really a natural
continum of storm types. I suppose that is why the ones that dont conform
to the definitions are so interesting. Also a single thunderstorm might
be of a different type over its existence. A dominant updraft of a
multicell might, given the right conditions, take on deep and persistent
rotation and that storm would then be a supercell. A single supercell
storm can be classic, HP or LP at different stages over its lifespan.
More interesting I find they can be cyclic (which I think I can recall
having read result from occlusion of the original updraft, and initiation
of a new adjacent one, by the advancing gustfront of the rear flank
downdraft) or splitting such as the one Jimmy D chased in Sydney back in
the spring of 1995.
>I know I've seen comments from (Michael Bath?)
>suggesting that most Australian mesos are spawned by classic HP supercells
>but has there been any serious work done on the various animals in our zoo?
I dont think there is enough info on this in Australia, although probably
my lack of understanding in this area (storm nomenclature) is the reason
why I find the labelling of past Australian storms confusing. I think I
can recall the recent (13/10) Brisbane supercell as being classed as a HP
although I dont know if that was official; what I found interesting was
that the TV footage showing what was thought to be the debris associated
with the weak tornado did occur with a clear sky as a backdrop. I could
see no evidence of any rain-wrapping or precipitation beyond that area,
which is a feature of HP supercells. Also, based on the radar imagery, a
bounded weak echo region was at the back of that storm while in many HP
cells the rotation is more towards the front. So I would be quite
interested if anyone can tell me the criteria used to determine the storm
type in that case.
Probably the most interesting storm i have ever seen a picture of in
Australia is that taken from near Orange in NSW (
http://members.xoom.com/wastorms/scell.html ). This storm is very
spectacular, but to me it just doesn't look like your typical supercell.
What does everyone think about that one??.
Another interesting one is the Shellharbour storm which Michael T chased
in March 1997 and which produced a rotating wall cloud and funnel. Being
so close to Sydney I thought there would be some radar imagery on that
one or some official comments on the storm type but there does not seem
to be. I wonder if that was a supercell or a severe multicell which
briefly developed a rotating updraft.
So I guess there are plenty of interesting storms waiting to be chased in
Australia and I am looking forward to what the chasers sorry 'observers'
of ASWA uncover in the next five or so years.
>
>Does anybody know of any web articles that adress these issues in an
>Australian context? Can I get a debate started here?? In the absense of
>ANY INSTABILITY AT ALL in dear old Adelaide - I wait with baited breath....
I dont know of any but I also would be very interested in this.
>What about non-supercell clouds that drop 'landspouts' (ie Cleve SA 1992)??t
>From what I can gather, most tornadoes which occur in the coastal strip
of SW WA, incl. Perth, are not spawned by supercells but are 'Line
squall' tornadoes which are associated with the passage of strong cold
fronts; these are also common in the UK I think.
As for the landspouts, they also are entirely different in their
formation and are more similar to non-mesocyclonic water spouts. I think
it is thought that their formation depends on the convergence of lower
level winds, which sets up weak lower level circulations and these are
intensified as they are streched by developing convective updrafts - that
is why they are usually seen below developing cells or cumulus congestus
and rapidly dissipate when a downdraft forms as the storm matures. This
is in contrast the mesocyclonic variety require both the updrafts and the
downdraft for their formation.
Cheers
David
--------------------------------------------------------------------------------------
024
Date: Mon, 04 Jan 1999 17:39:25 +1100
From: Michael Scollay [michael.scollay at telstra.com.au]
Organization: Telstra Strategy & Research
X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m)
X-Accept-Language: en
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Web Photos
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Michael Thompson wrote:
>
> Different programs measure compression in different ways...
And some programs display the same file differently. Be aware of this
since in resource-rich computers, some apps running in background or
multi-task mode gobble up resources needed by other apps which
otherwise just try their best to display using the limited resources
available.
Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
025
X-Sender: jimmyd at pop.ozemail.com.au
X-Mailer: QUALCOMM Windows Eudora Pro Version 4.1
Date: Mon, 04 Jan 1999 18:28:55 +1100
To: aussie-weather at world.std.com
From: Jimmy Deguara [jimmyd at ozemail.com.au]
Subject: aussie-weather: Lifted Index charts
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
I am not quite sure but it seems that the Lifted Index model charts are
playing up so be careful in using it. For instance, the forecast for
tomorrow at 00z, 03z, 06z seem to be the same or seem to not change....
So be carefull at the momenr. this is the first hickup since I have been
using this resource.
Jimmy
--------------------------------------------------------------------------------------
026
Date: Mon, 4 Jan 1999 18:33:07 +1100 (EST)
From: Paul Graham [pgraham1 at mail.usyd.edu.au]
To: aussie-weather at world.std.com
Subject: aussie-weather: Thickness and Temperature...
Reply-Receipt: pgraham1 at extro.ucc.su.oz.au
Reply-Read: pgraham1 at mail.usyd.edu.au
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Hi Michael + everyone,
I think that thickness surfaces are directly related to isothermal
surfaces. In other words a surface of equal thickness is isothermal.
Another way of thinking of it is: a warm atmosphere is "stretched" while
a cool atmosphere is "compressed" so that pressure decreases more rapidly
with height in a cool atmosphere than it does in a warm atmosphere.
- Paul G.
----------------------------
Paul Graham
paul at marconi.mpce.mq.edu.au
----------------------------
On Mon, 4 Jan 1999, Michael Scollay wrote:
> Blair Trewin wrote:
> >
> > All the models are suggesting some seriously warm weather in
> > Melbourne in the first half of next week - thicknesses Monday/Tuesday
> > next week peak around 574-579, depending on the model - this could
> > well mean close to or over 40.
>
> Is there a correllation / formulae / tables / rule-of-thumb that
> relates 500-1000mb thickness to temperature at particular altitudes
> e.g. 1000mb, 850mb etc.
>
> Michael Scollay mailto:michael.scollay at telstra.com.au
--------------------------------------------------------------------------------------
027
From: "Michael Thompson" [michaelt at ozemail.com.au]
To: [aussie-weather at world.std.com]
Subject: Re: aussie-weather: Atypical Storms
Date: Mon, 4 Jan 1999 17:36:10 +1100
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I must admit that I have been a fan of wind shear for a while now, I like to
see a tower at 45 degrees, not one shooting straight up.
You must separate the downdraft and updraft for long life.
Michael
-----Original Message-----
>From: Phil Bagust
>To: aussie-weather at world.std.com
>Date: Monday, 4 January 1999 8:59
>Subject: Re: aussie-weather: Atypical Storms
>
>
>>Take a look at this page for information on atypical storm types:
>>
>>http://www.nssl.noaa.gov/swat/Cases/cases_pix.html
>>
>>Sam Barricklow
>
>I urge people to do just that. It's a fascinating set of pages and images.
>what struck me was the variety of beasties that can produce rotating mesos.
>
>Low topped supercells I'd heard of, but mini-supercells are a new one to
me.
>What seems to be consistent (although I've only scratched the surface here)
>is that shear is just as, if not more important than instability in
>producing rotating systems. Some of those mini-supercells seemed like they
>might have been quite unimpressive visually - yet they still produced
>tornados!
>
>The other thing is the Australian aspect. How closely do US thunderstorm
>morphologies match ours? I know I've seen comments from (Michael Bath?)
>suggesting that most Australian mesos are spawned by classic HP supercells
>but has there been any serious work done on the various animals in our zoo?
>What about non-supercell clouds that drop 'landspouts' (ie Cleve SA 1992)??
>
>Does anybody know of any web articles that adress these issues in an
>Australian context? Can I get a debate started here?? In the absense of
>ANY INSTABILITY AT ALL in dear old Adelaide - I wait with baited breath....
--------------------------------------------------------------------------------------
028
From: "James Chambers" [jamestorm at ozemail.com.au]
To: "Aussie Weather" [aussie-weather at world.std.com]
Subject: aussie-weather: SA Thunderstorms
Date: Mon, 4 Jan 1999 21:55:50 +1000
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Hi all, anyone in Adelaide/other parts of WA who wants to tell us what's
happening?
PRIORITY - FOR BROADCAST AS SOON AS POSSIBLE
SEVERE THUNDERSTORM ADVICE
Bureau of Meteorology Adelaide
Issued at 8.55 PM on Monday , 04/01/99
For people in the Flinders, Mid North, Riverland and Murraylands
districts, Eastern Eyre Peninsula and the southern parts of the
Northwest and Northeast Pastoral districts (south of Minnipa to
Woomera to Mildura.)
Localised severe wind gusts are possible with thunderstorms in the
above districts this evening.
Isolated damage is possible and people are advised to take
precautions, such as to secure loose outside objects.
Thunderstorms are expected weaken during the next 3 hours.
------------------------------------------------------
James Chambers
http://www.ozemail.com.au/~jamestorm/bristorm.html
--------------------------------------------------------------------------------------
029
From: "Michael Thompson" [michaelt at ozemail.com.au]
To: [aussie-weather at world.std.com]
Subject: Re: aussie-weather: Atypical Storms
Date: Mon, 4 Jan 1999 22:55:31 +1100
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I must admit that I have always doubted this as a supercell, there is no
evidence of wind shear at all, and that worries me. What time of year was
this taken ? I could be a cold Cb, with small hail and even snow if taken
Aug - Sep.
>Probably the most interesting storm i have ever seen a picture of in
>Australia is that taken from near Orange in NSW
>http://members.xoom.com/wastorms/scell.html ). This storm is very
>spectacular, but to me it just doesn't look like your typical supercell.
>What does everyone think about that one??.
>
>Another interesting one is the Shellharbour storm which Michael T chased
>in March 1997 and which produced a rotating wall cloud and funnel. Being
>so close to Sydney I thought there would be some radar imagery on that
>one or some official comments on the storm type but there does not seem
>to be. I wonder if that was a supercell or a severe multicell which
>briefly developed a rotating updraft.
>
No radar was available or so I was told when I asked a few weeks later. I
still do not know to this day whether it was supercell or not, but one thing
was sure, there was strong wind shear, whether this was just in one
direction or not I do not know, but the towers earlier in the day had that
45 degree lean to them. After passing to sea the storm built an impressive
back shearing anvil, and not a thin one, but a real chunky wedge with bumps.
Michael
--------------------------------------------------------------------------------------
030
From: wbc at ozemail.com.au (Laurier Williams)
To: aussie-weather at world.std.com
Subject: Re: aussie-weather: Orange AWS
Date: Mon, 04 Jan 1999 13:12:35 GMT
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On Mon, 4 Jan 1999 12:47:40 +1100, "Terry Bishop"
wrote:
Hi Terry. I missed the earlier part of this thread, so scuse me if I'm
repeating anything or missing points.
> I feel if they could move the AWS to another site such as our Dept. Ag.
>Research station which is situated on the Southern edge of town or the
>Orange Ag. college which is a branch of the Uni. of Sydney situated on the
>Northern edge of town the recording would be more representive of the City
>of Orange climate.
Actually, manual readings are taken and reported daily from the
"Orange Agricultural Institute" -- though they are only 9am, and only
Mon to Fri, there being no weather at the weekend ;-)
With both a manual and auto station at the airport, and this one in
town, Orange is quite well served for daily reporting stations. The
only other town that I can think of off the top of my head that's so
well served is Glen Innes, where the PO, Airport (AWS) and Ag Station
all report daily! By sad comparison, Tamworth has only one AWS which
routinely goes off the air with one parameter or another.
Cheers
--
Laurier Williams
Australian Weather Links and News
http://www.ozemail.com.au/~wbc/
--------------------------------------------------------------------------------------
031
X-Sender: paisley at mail.cobweb.com.au
Date: Mon, 4 Jan 1999 17:35:46 +0930
To: aussie-weather at world.std.com
From: Phil Bagust [mail.cobweb.com.au at redback.cobweb.com.au]
Subject: Re: aussie-weather: Adelaide firing up!
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Whooa!
Just got the shock of my life after stepping out of my office at Uni.
After 4 hours inside a semicircle of cumulus towers and anvils north and
northeast of the city perhaps 25-40km out.
Current temp 39
Might head out after rush hour finishes if there's anything to chase....
--------------------------------------------------------------------------------------
032
From: "Mark Hardy" [mhardy at nsw.bigpond.net.au]
To: [aussie-weather at world.std.com]
Subject: Re: aussie-weather: Thickness and Temperature...
Date: Mon, 4 Jan 1999 19:10:11 +1100
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Paul
Thickness surfaces and isothermal surfaces are not quite the same. Thickness
is proportional to the temperature of the 1000-500hPa layer. Whereas the
isotherm surface represents a temperature slice. Therefore the shape of an
isothermal surface is largely linked to the stability of the underlying
layers. This would not be the same shape as a thickness surface.
(I think)
But yes, there are plenty of correlations between thickness, 850hPa temp etc
and theoretical max temps. The correlations are season, latitude and
location dependent. For example at this time of year T850 + 20C will give
you the theoretical max posssible temp. A thickness of 580 will often give
temps above 40.
Mark
-----Original Message-----
>From: Paul Graham
>To: aussie-weather at world.std.com
>Date: Monday, 4 January 1999 18:41
>Subject: aussie-weather: Thickness and Temperature...
>
>
>Hi Michael + everyone,
> I think that thickness surfaces are directly related to isothermal
>surfaces. In other words a surface of equal thickness is isothermal.
>Another way of thinking of it is: a warm atmosphere is "stretched" while
>a cool atmosphere is "compressed" so that pressure decreases more rapidly
>with height in a cool atmosphere than it does in a warm atmosphere.
>- Paul G.
--------------------------------------------------------------------------------------
033
X-Sender: paisley at mail.cobweb.com.au
Date: Mon, 4 Jan 1999 19:32:12 +0930
To: aussie-weather at world.std.com
From: Phil Bagust [mail.cobweb.com.au at redback.cobweb.com.au]
Subject: Re: aussie-weather: Assesing the Potential for Severe wx
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
> Hey Ben from Brisbane here
Thanks for that mountain of stuff Ben, It'll keep me busy for weeks.
Phil 'Paisley' Bagust
paisley at cobweb.com.au
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034
X-Sender: paisley at mail.cobweb.com.au
Date: Mon, 4 Jan 1999 19:36:47 +0930
To: aussie-weather at world.std.com
From: Phil Bagust [mail.cobweb.com.au at redback.cobweb.com.au]
Subject: Re: aussie-weather: SA severe storms
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
Severe T-storm warnings are now current over virtually the whole of the
state NE of Adelaide. Just got back from a short (25k) drive to Ridge rd
at the top of the Mt Lofty ranges to chack out several cells further out to
the NE. Took several pics. But the anvils are starting to spread and I
cant see any more explosive convection.
Tomorrow. Now that will be the day.
| Document: 990104.htm
Updated: 15th January, 1999 |
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