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Storm News
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Australian Weather Mailing List Archives: Tuesday, 29 June 1999 |
From Subject
--------------------------------------------------------------------------------------
001 John Woodbridge [jrw at pixelcom.net] Rain Gauge
002 Anthony Cornelius [cyclone at flatrate.net.au] SE QLD wx
003 "Phil Schubert" [philip at zedley.com] Rain Gauge
004 Paul Graham [v_notch at hotmail.com] snow in Sydney
005 Paul Graham [v_notch at hotmail.com] Melbourne.
006 Michael Scollay [michael.scollay at telstra.com. snow in Sydney
007 Anthony Cornelius [cyclone at flatrate.net.au] snow in Sydney and Brisbane
008 Ben Quinn [bodie at flatrate.net.au] SE QLD wx
009 Ben Munro [benjamin at biosys.net] Fog in Sydney
010 wbc at ozemail.com.au (Laurier Williams) Standards of observation (was Rain Gauge)
011 Kevin Burrows [k.burrows at bom.gov.au] Standards of observation (was Rain Gauge)
012 "Andrew Miskelly" [amiskelly at ozemail.com.au] MRF
013 Blair Trewin [blair at met.Unimelb.EDU.AU] Standards of observation (was Rain Gauge)
014 Lindsay [writer at lisp.com.au] snow in Sydney
015 John Woodbridge [jrw at pixelcom.net] SE QLD wx
016 John Woodbridge [jrw at pixelcom.net] snow in Sydney and Brisbane
017 John Woodbridge [jrw at pixelcom.net] Standards of observation (was Rain Gauge)
018 Kevin Burrows [k.burrows at bom.gov.au] Standards of observation (was Rain Gauge)
019 wbc at ozemail.com.au (Laurier Williams) Standards of observation (was Rain Gauge)
020 Paul Graham [v_notch at hotmail.com] Tornado Encounter...
021 "Paul Rands" [prands at healey.com.au] Fog in Sydney
022 "Jason" [kevans at kisser.net.au] Cyclone Thelma Report
023 Kevin Phyland [kjphyland at hotmail.com] Standards of observation (was Rain Gauge)
024 Tom Johnstone [Iain.Johnstone at pse.unige.ch] snow in Sydney
025 Keith Barnett [weather at ozemail.com.au] Not much rain south of Illawarra
026 "Matthew Piper" [mjpiper at ozemail.com.au] Davis Weather Monitor II
027 Rod Aikman [raikman at hotmail.com] Standards of observations
028 "John Graham" [gorzzz at one.net.au] Davis Weather Monitor II
--------------------------------------------------------------------------------------
001
From: John Woodbridge [jrw at pixelcom.net]
To: "'aussie-weather at world.std.com'" [aussie-weather at world.std.com]
Subject: RE: aus-wx: Rain Gauge
Date: Tue, 29 Jun 1999 01:52:15 +1000
Organization: Pixel Components Pty Ltd
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Hi me again,
Yes well the errant dogs could be a problem (wallabies in my case...). If
the accuracy of the instrument is known well naturally that applies. In
some cases it goes the other way, e.g., I have a machine that measures
humidity in 1% increments, but the literature states that the accuracy is
only plus or minus 10%. So why did they bother I wonder... Still I think
it is a good rule of thumb where the accuracy is not known .
Not sure I understand your issue with lack of 'odd' numbers. Presumably so
long as you use some rule which on average splits the 'halfway' readings
evenly up or down then all is OK. (e.g., with .2 graduations, divide by 2
first, apply the odd rule, then x2). But then again, the important thing
is probably to compare apples with apples not oranges. If the BoM specify
round up, then should we all not do the same so that rainfall figures can
be compared meaningfully with recorded averages over time?
Regards,
John.
>snip
I think that, regardless of instrument accuracy, what's most important
is to avoid the "round-up" rule. The rule in all scientific areas
where figures are averaged, totalled or otherwise manipulated is to
round to the odd figure. Otherwise you are building in error. The
problem with the Bureau's 0.2mm rule is that there is no odd figure to
round to, and in an area with 150 raindays in a year, the annual total
will be systematically inflated, on average, by 75 x 0.1 = 7.5mm.
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002
Date: Tue, 29 Jun 1999 09:11:24 +1000
From: Anthony Cornelius [cyclone at flatrate.net.au]
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To: aussie-weather at world.std.com
Subject: Re: aus-wx: SE QLD wx
Sender: aussie-weather-approval at world.std.com
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Hi all,
What is very ordinary rain, has caused some 'phenomenal' flooding!
>From 9am Sunday to 9am yesterday, we had 58.6mm, this caused Bulimba Crk
to rise around 4m and flood Wrights Rd, this has only ever happened in
the worse of flooding, yesterday they closed the road - the 4th time it
has ever been closed in 11yrs, it's now been closed twice this year. I
think this just shows how damp and soggy everything still is! Our back
yard is just a mud bath now, you can't walk on it without sinking a few
inches in mud...and my dog is loving it!! :(
North Pine Dam (just to the N of Brisbane) is currently letting go water
yet again, they've been doing this periodically since Feb.
We had a further 19.7mm from 9am yesterday to today, last night there
were a few short, sharp, bursts of heavy rain, and a few rumbles of
thunder (yes, I've had my 0.2 of a thunderday now! )
This boosts my June total to 189.2mm - the average is 72mm (from the BoM
calander, although I've seen a few different quoted figures...) I have
had 916mm this year.
There is still more to come by the looks of it (but this will fall into
July).
Anthony from Brisbane
Ben Quinn wrote:
>
> Hey Ben from Brisbane here..
>
> 11:45pm here and i just got woken up by a Cg.. this is the fourth night
> in a row i have had thunder with 10-15 rumbles over a few hours each
> night.. isn't it JUNE?!?! :)
>
> BTW i had 37mm here last night, which is pretty ordinary really (but
> nice for this time of year).. others scored much better with some falls
> up to 100mm in the southern suburbs of Brisbane and plenty of falls
> around 40-60 in coastal areas..
>
> As i write this email lightning more frequent and drawing closer with
> moderate/heavy rain..
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> -----------------------jacob at iinet.net.au------------------------------
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003
From: "Phil Schubert" [philip at zedley.com]
To: [aussie-weather at world.std.com]
Subject: RE: aus-wx: Rain Gauge
Date: Tue, 29 Jun 1999 07:53:01 +0800
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John
Woodbridge wrote:
Sent: Monday, 28 June 1999 23:52
To: 'aussie-weather at world.std.com'
Subject: RE: aus-wx: Rain Gauge
Not sure I understand your issue with lack of 'odd' numbers. Presumably so
long as you use some rule which on average splits the 'halfway' readings
evenly up or down then all is OK. (e.g., with .2 graduations, divide by 2
first, apply the odd rule, then x2). But then again, the important thing
is probably to compare apples with apples not oranges. If the BoM specify
round up, then should we all not do the same so that rainfall figures can
be compared meaningfully with recorded averages over time?
I have a new Nylex gauge, an note that on many occasions there is still a
fair amount of drops beaded up in the funnel portion. I try to shake these
down into the measure, and often they will amount to .02mm. With
intermittent showers in windy periods these would evaporate. I think this
would constitute a larger error over time.
Maybe some wetting agent (CRC) should be added.
Cheers
Phil
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004
X-Originating-Ip: [210.84.11.137]
From: Paul Graham [v_notch at hotmail.com]
To: aussie-weather at world.std.com
Subject: Re: aus-wx: snow in Sydney
Date: Mon, 28 Jun 1999 16:54:03 PDT
Sender: aussie-weather-approval at world.std.com
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Hi Michael,
I do seem to remember the weather Bureau suggesting the chance of snow falls
in Sydney that afternoon - I think this was based on reports of snow in some
southern suburbs. But as Don White mentioned, it was really soft hail as 6C
is too warm for snow. However, I recall the "flakes" as falling in the same
way as snow does (with the same aerodynamic characteristics) which convinced
me it was snow rather than hail.
- Paul G.
>From: "Michael Thompson"
>Reply-To: aussie-weather at world.std.com
>To:
>Subject: Re: aus-wx: snow in Sydney
>Date: Mon, 28 Jun 1999 23:19:03 +1000
>
>I remember this event well in the Illawarra. The temperature peaked at
>something like 16C earlier in the day, but a fast moving front with
>cold SW winds and an associated cloud band dramatically dropped the
>temperature around 1-2pm, with the front the temperature plummeted down to
>something like 6C here,
>something I have never seen before or since of at that time of afternoon
>here.
>
>Snow fell on the Illawarra escarpment down to very low levels, I drove up
>Macquarie Pass and the first snow on ground was seen well short of the top
>at approx 400-500m, this was an hour after the fall and it must
>of fell lower. perhaps 250-300m. Snow flurries were reported from the F6
>toll gates and the
>top of Mt Kiera.
>
>Despite the cold no snow fell at my home, just cold bitter rain. Some radio
>reports did mention snow, but I am always the doubter, 6C just is not cold
>enough.
>
>Michael
>
>
>
>
> > I remember the time in 1986 (possibly August) when there was a brief
> > snowfall through parts of Sydney. It lasted about 10 minutes but melted
> > fairly quickly after settling on the ground. I'd be interested to know
>what
> > the temperature was at the time since, although it was cold, I don't
>think
> > it was exceptionally cold. I seem to remember that the cloud was a tall
> > cumulus and this may have been a factor.
> > - Paul G.
>
>
>
>
>
>
>
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> -----------------------jacob at iinet.net.au------------------------------
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005
X-Originating-Ip: [210.84.11.137]
From: Paul Graham [v_notch at hotmail.com]
To: aussie-weather at world.std.com
Subject: aus-wx: Melbourne.
Date: Mon, 28 Jun 1999 17:03:15 PDT
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Hi to Melbournians...
I will be in Melbourne next week (from Tuesday) so if you live there we may
be able to meet up. Just send some e-mail to me at:
paul at marconi.mpce.mq.edu.au
Cheers,
Paul.
(I think there is the "Science in the Pub" which may be worth going along
to...)
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006
Date: Tue, 29 Jun 1999 10:32:18 +1000
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: aus-wx: snow in Sydney
Sender: aussie-weather-approval at world.std.com
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Paul Graham wrote:
>
> Hi Michael,
> I do seem to remember the weather Bureau suggesting the chance of
> snow falls in Sydney that afternoon - I think this was based on
> reports of snow in some southern suburbs. But as Don White
> mentioned, it was really soft hail as 6C is too warm for snow.
> However, I recall the "flakes" as falling in the same
> way as snow does (with the same aerodynamic characteristics)
> which convinced me it was snow rather than hail.
> - Paul G.
My obs of "warm" snow in since I started watching such stuff
from 1973 follows. But I can imagine that given the right
conditions, obs of "snow" in Sydney could go to quite high
temps. Maybe not as high as 6C but maybe 4C to 5C;
There is a relationship between cloud-level, lapse rate and
humidity. When clouds in Katoomba had bases around 2500m,
the RH might have been 60-70% and the lapse-rate enormous
with 4C in Katoomba and 16C in Sydney. Under these conditions,
I've seen very decent snow flakes make it to the ground and
melt on contact with "ice" in the precipitation to temps
approaching 6C. Total ice in the precipitation would come
in around 4C with nice light snow falling from about 1C
down. Accummulation was a function of intensity and ground
temp which in Katoomba would not normally happen until about
-0.5C was reached. In Perisher Valley on rare occasions when
the RH is low, I've seen snow come from a long way up when
the temp is a high as 6C! This would actually accumulate on
top of existing snow cover creating a nice slushy layer.
Bring the clouds down to the deck and forget such sites.
Under high humidity conditions, you need temps below 0C with
first flakes appearing at about +0.5C. On one occasion last
year, the temp was -3C in Perisher (1730m) and -2C in
Jindabyne (900m?) with really heavy snow falling over the
entire altitude range. Now that was an easterly storm with
a 1000mb-500mb thickness around 5340m. Somewhat weird (the
lousy lapse rate) if you ask me. I could "go on" about snow
but that'll do:-)
Michael Scollay mailto:michael.scollay at telstra.com.au
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007
Date: Tue, 29 Jun 1999 11:03:48 +1000
From: Anthony Cornelius [cyclone at flatrate.net.au]
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Subject: Re: aus-wx: snow in Sydney and Brisbane
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Hi all,
To throw in another variable, on the 1st of May, there was snow reported
just to the SW of Brisbane (near Woodridge). Jeff C. was telling me
about this, he was as surprised as I was! I immediately suggested that
there we saw a lot of hail that looked like snow on the ground, however
it was reported as falling.
Temperatures would have been in the low twenties, but under cloud, in
the mid-high teens - under precip, possibly even close to 12-13C
Could soft, melted hail have caused it to look like snow? As it seemed
far too warm for snow!!
Anthony Cornelius
Paul Graham wrote:
>
> Hi Michael,
> I do seem to remember the weather Bureau suggesting the chance of snow falls
> in Sydney that afternoon - I think this was based on reports of snow in some
> southern suburbs. But as Don White mentioned, it was really soft hail as 6C
> is too warm for snow. However, I recall the "flakes" as falling in the same
> way as snow does (with the same aerodynamic characteristics) which convinced
> me it was snow rather than hail.
> - Paul G.
>
> >From: "Michael Thompson"
> >Reply-To: aussie-weather at world.std.com
> >To:
> >Subject: Re: aus-wx: snow in Sydney
> >Date: Mon, 28 Jun 1999 23:19:03 +1000
> >
> >I remember this event well in the Illawarra. The temperature peaked at
> >something like 16C earlier in the day, but a fast moving front with
> >cold SW winds and an associated cloud band dramatically dropped the
> >temperature around 1-2pm, with the front the temperature plummeted down to
> >something like 6C here,
> >something I have never seen before or since of at that time of afternoon
> >here.
> >
> >Snow fell on the Illawarra escarpment down to very low levels, I drove up
> >Macquarie Pass and the first snow on ground was seen well short of the top
> >at approx 400-500m, this was an hour after the fall and it must
> >of fell lower. perhaps 250-300m. Snow flurries were reported from the F6
> >toll gates and the
> >top of Mt Kiera.
> >
> >Despite the cold no snow fell at my home, just cold bitter rain. Some radio
> >reports did mention snow, but I am always the doubter, 6C just is not cold
> >enough.
> >
> >Michael
> >
> >
> >
> >
> > > I remember the time in 1986 (possibly August) when there was a brief
> > > snowfall through parts of Sydney. It lasted about 10 minutes but melted
> > > fairly quickly after settling on the ground. I'd be interested to know
> >what
> > > the temperature was at the time since, although it was cold, I don't
> >think
> > > it was exceptionally cold. I seem to remember that the cloud was a tall
> > > cumulus and this may have been a factor.
> > > - Paul G.
> >
> >
> >
> >
> >
> >
> >
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> > message.
> > -----------------------jacob at iinet.net.au------------------------------
>
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008
Date: Tue, 29 Jun 1999 11:48:01 +1000
From: Ben Quinn [bodie at flatrate.net.au]
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Subject: aus-wx: SE QLD wx
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Hey Ben from Brisbane here..
I got a stormy 36mm overnight, bringing my total for this event to
73mm.. and my total for this month is now 223mm (possibly minus a
suspect 17mm).. this month we have had many days with large Cb sitting
off the coast.. maybe 12-13 days.. and a few nights with lightning off
the coast.. and 5 thunderdays here in Redcliffe.. some other places on
the coast would have had more like 6 or 7 thunderdays..
Some large Cu and Tcu moving onto the coast again, and you know if
you're under one of them as the showers are very heavy, although brief..
Went and photographed the north pine dam with the floodgates open this
morning.. from the bottom of a hill.. after i fell down it.....
(* at &#Y# at $)$#*( at ($#$..
Some nice falls to 9am in the SE quarter of Queensland again.. some of
these places would be nearing the 150-200mm mark for this event..
Palmwoods 100
Nambour 98
Eumundi 85
Cooran 83
Long Pocket 79 (3 days)
Peachester 74
Toowong 74 (3 days)
Landsborough 72
Cooroibah 70
Rainbow Beach 66
Caboolture 65
Yandina 65
Boreen Point 62
Maleny 62
Lytton 60
Kenilworth 58
Mary Cairncross 54
Beerburrum 53
Morayfield 43
Imbil 41
Goomboorian 40
Mt Mee 40
Beechmont 39
Beenleigh 36
Logan City 36
Redcliffe 36
Maroochydore 35
And a scattering of falls from 10-30mm..
The models look interesting for parts of NSW over the next 48 hours or
so.. and once again possibly more upper level action for us at various
times over the next 7 days..
BRING IT ON!!!!!!!!!!!!!!!!!!!!!!!!!! :)
Anthony Cornelius wrote:
>
> Hi all,
>
> What is very ordinary rain, has caused some 'phenomenal' flooding!
>
> >From 9am Sunday to 9am yesterday, we had 58.6mm, this caused Bulimba Crk
> to rise around 4m and flood Wrights Rd, this has only ever happened in
> the worse of flooding, yesterday they closed the road - the 4th time it
> has ever been closed in 11yrs, it's now been closed twice this year. I
> think this just shows how damp and soggy everything still is! Our back
> yard is just a mud bath now, you can't walk on it without sinking a few
> inches in mud...and my dog is loving it!! :(
>
> North Pine Dam (just to the N of Brisbane) is currently letting go water
> yet again, they've been doing this periodically since Feb.
>
> We had a further 19.7mm from 9am yesterday to today, last night there
> were a few short, sharp, bursts of heavy rain, and a few rumbles of
> thunder (yes, I've had my 0.2 of a thunderday now! )
>
> This boosts my June total to 189.2mm - the average is 72mm (from the BoM
> calander, although I've seen a few different quoted figures...) I have
> had 916mm this year.
>
> There is still more to come by the looks of it (but this will fall into
> July).
>
> Anthony from Brisbane
>
> Ben Quinn wrote:
> >
> > Hey Ben from Brisbane here..
> >
> > 11:45pm here and i just got woken up by a Cg.. this is the fourth night
> > in a row i have had thunder with 10-15 rumbles over a few hours each
> > night.. isn't it JUNE?!?! :)
> >
> > BTW i had 37mm here last night, which is pretty ordinary really (but
> > nice for this time of year).. others scored much better with some falls
> > up to 100mm in the southern suburbs of Brisbane and plenty of falls
> > around 40-60 in coastal areas..
> >
> > As i write this email lightning more frequent and drawing closer with
> > moderate/heavy rain..
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> > message.
> > -----------------------jacob at iinet.net.au------------------------------
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009
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Date: Tue, 29 Jun 1999 12:14:57 +1000
To: aussie-weather at world.std.com
From: Ben Munro [benjamin at biosys.net]
Subject: aus-wx: Fog in Sydney
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
There was a thick fog in sydney last night. At least, there was in my part
of sydney ( the hills in the north west). I got up at 2am and couldn't see
the other side of the road, which is less than 20 metres away, even though
there are street lights. It was all gone by 6am this morning though.
On another topic, it has rained for the last eight days here, about 30mm in
total, not a lot of rain. The total for this month is about 55mm so far,
the average for June is 100mm.
Ben Munro
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010
From: wbc at ozemail.com.au (Laurier Williams)
To: aussie-weather at world.std.com
Subject: Re: aus-wx: Standards of observation (was Rain Gauge)
Date: Tue, 29 Jun 1999 02:36:05 GMT
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On Tue, 29 Jun 1999 01:52:15 +1000, John Woodbridge
wrote:
>Not sure I understand your issue with lack of 'odd' numbers. Presumably so
>long as you use some rule which on average splits the 'halfway' readings
>evenly up or down then all is OK. (e.g., with .2 graduations, divide by 2
>first, apply the odd rule, then x2).
Hi John. Yes, I agree, but it becomes sufficiently complex for the
average observer not to be done.
>But then again, the important thing
>is probably to compare apples with apples not oranges. If the BoM specify
>round up, then should we all not do the same so that rainfall figures can
>be compared meaningfully with recorded averages over time?
>
I'd agree with that if the Bureau weren't out of step with the rest of
the world. The prime advantage of recording to 0.1mm with standard
gauges (which have measuring glasses graduated to 0.2mm) IMHO, is
that it usually removes the need to consider rounding at all -- the
eye will usually determine the water level to be on or between a
graduation.
Unfortunately for meaningful comparisons, a large proportion (~30% on
a quick inspection) of bureau observers record to the nearest 0.1. Of
the remainder that record to 0.2, we have no certainty that they round
up or down. Again, this uncertainty would be removed it the Bureau
stipulated recording to the nearest 0.1, as they do with temperature,
dew point, pressure, evaporation, sunshine.....
I guess my concern over this apparently trivial issue stems from the
larger number of practices where we are strangely out of step with the
rest of the meteorological world, and which I believe reduce the
quality of our observational program.
-- Every country in the world except Australia and some Pacific
Islands where the met service was set up by Australia takes
observations at 00, 03, 06... UTC. We persist with 9am, noon... local
time, which is 23 UTC in the east, 23.30 UTC in SA/NT, and 01 UTC in
WA. From what I have been able to work out, this is a historical
remnant from the days when the local Post Offices did most of the
reading, and 9am and 3pm were convenient times to get the first obs of
the day when the staff arrived, and the last obs of the day in time
for the Bureau to process before Bureau staff left for the day.
-- Every country in the world except Australia and NZ retain their
observational schedule on 00, 03.. UTC during daylight saving. We
stick to clock time, so that suddenly 9am becomes 8am, as it were, and
real time measurements like temperature and humidity are not
comparable within months that switch to or from DST, or between the
DST and pre-DST era. Maximum temperatures for the day continue to be
reported at 3pm local DST, which is 2pm local, and frequently before
the day's maximum has occurred.
-- Every country in the world except Australia records the three major
cllimatological parameters of rainfall, max and min temperature so as
to most closely align them with the local calendar day. Our fixation
with 9am results in true max and min temps often being lost during
periods of abnormal temperature variation.
-- Every country in the world except Australia adopts standard, agreed
WMO reporting codes which are either global, regional or national. We
have not updated our national reporting code for at least the last 30
years to my knowledge, with the result that it now has elements that
confuse observers and cause errors (particularly in rainfall
reporting), and completely ignores elements that are routinely
reported elsewhere such as sunshine, evaporation, wind gustiness and
snow depth.
I won't go on, but I do despair at times at the conservatism and "near
enough is good enough" attitudes that I believe are not giving us the
quality of weather observations in this country that we could, and
should, have.
--
Laurier Williams
Australian Weather Links and News
http://www.ozemail.com.au/~wbc/
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011
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Date: Tue, 29 Jun 1999 13:19:01 +0900
To: aussie-weather at world.std.com
From: Kevin Burrows [k.burrows at bom.gov.au]
Subject: Re: aus-wx: Standards of observation (was Rain Gauge)
Sender: aussie-weather-approval at world.std.com
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Hi All,
I am not going to respond to all that has recently been written on the
subject particularly Laurier's last email. However I can make a few comments.
1. On the subject of the time at which maximum and minimum temperatures
and daily rainfall are recorded. The WMO suggest that these items are
reported on the first observation at or after 00z and 12z. The problem is
that these times do not always correspond with the daily cycle. If we go
by local time its a bit difficult to get observers up at midnight to take
observations. Many observers take observations as part of their normal job
and get paid for out of hours observations. Introducing midnight
observations would be extremely expensive.
By the way the USA also has a wide variety of times of reading the MAX
temperature too.
2. Going to UTC observations at 00z and then every three hours creates the
same problems. In SA and the eastern states the max would be being read at
0930 CST and 1000EST. If we shift the time to read the max back to 21Z
then we still have problems in availablity of observers and extra cost.
Remember we dont have Automatic Weather Stations at most observing sites.
3. Its important for climate change studies to maintain a standard time of
observations and this is one reason for our reluctance to change. When you
looking for small changes in temperature over long periods you dont want
the data set corrupted by changes introduced by changes of instrument, site
or observation time.
4. Observations are stored in the database against their standard local
time therefore Adelaide 9am obs in Summer are stored with a time of 0800CST.
5. The Bureau is introducing a new format for transmitting data
internally. Its called the Met Data Format (MDF) and is being introduced
with Electronic Field Books (Laptop PC's). The observer will transmit all
observations in real time and these go straight into the computer database.
Evaporation, maximum wind gust, max and min temps and rainfall to the
nearest 0.1�C or 0.2mm ( I wont comment about reading rainfall to the
nearest 0.1mm apart from sayin that if an observer reports observations to
the nearest 0.1mm then thats how the data is stored) will be reported in
real time where these elements are observed. We still have to use the
SYNOP code for international data exchange. Paper field books will no
longer be used and most of the quality control will be done by the
electronic field book.
Kevin Burrows
*********************************************************************
* Kevin Burrows * *
* Meteorologist * PO Box 421 *
* Climate and Consultative Services * Kent Town *
* South Australian Regional Office * South Australia 5071 *
* Bureau of Meteorology * *
* * Phone: (08) 8366 2691 *
* internet: k.burrows at bom.gov.au * Fax: (08) 8366 2693 *
*********************************************************************
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012
From: "Andrew Miskelly" [amiskelly at ozemail.com.au]
To: [aussie-weather at world.std.com]
Subject: aus-wx: MRF
Date: Tue, 29 Jun 1999 14:00:53 +1000
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Hey all,
Just found it interesting that for Thursday the MRF Model
(http://grads.iges.org/pix/aus2.48hr.gif) forcasts a 534 thickness for
Adelaide. If this were to come true it is supposed to disipate before it
gets much further east, could have been fun and games!
--
Andrew Miskelly
Illawarra/Southern Tablelands
amiskelly at ozemail.com.au
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013
From: Blair Trewin [blair at met.Unimelb.EDU.AU]
Subject: Re: aus-wx: Standards of observation (was Rain Gauge)
To: aussie-weather at world.std.com
Date: Tue, 29 Jun 1999 14:16:45 +1000 (EST)
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Laurier Williams wrote:
> On Tue, 29 Jun 1999 01:52:15 +1000, John Woodbridge
> wrote:
>
> >Not sure I understand your issue with lack of 'odd' numbers. Presumably so
> >long as you use some rule which on average splits the 'halfway' readings
> >evenly up or down then all is OK. (e.g., with .2 graduations, divide by 2
> >first, apply the odd rule, then x2).
>
> Hi John. Yes, I agree, but it becomes sufficiently complex for the
> average observer not to be done.
>
> >But then again, the important thing
> >is probably to compare apples with apples not oranges. If the BoM specify
> >round up, then should we all not do the same so that rainfall figures can
> >be compared meaningfully with recorded averages over time?
> >
> I'd agree with that if the Bureau weren't out of step with the rest of
> the world. The prime advantage of recording to 0.1mm with standard
> gauges (which have measuring glasses graduated to 0.2mm) IMHO, is
> that it usually removes the need to consider rounding at all -- the
> eye will usually determine the water level to be on or between a
> graduation.
>
> Unfortunately for meaningful comparisons, a large proportion (~30% on
> a quick inspection) of bureau observers record to the nearest 0.1. Of
> the remainder that record to 0.2, we have no certainty that they round
> up or down. Again, this uncertainty would be removed it the Bureau
> stipulated recording to the nearest 0.1, as they do with temperature,
> dew point, pressure, evaporation, sunshine.....
While this is of concern, I'm rather more concerned by the possibility
that, on the evidence of a test study I've just undertaken of
district 17 (north-eastern SA), something like 50% of rainfalls
between 0.2 and 2 mm aren't being recorded at all...(the climatological
expectation, based on synoptic stations like Marree, Oodnadatta and
Birdsville, is that 40-50% of all raindays will have > 2mm, but
about 65% of stations have a proportion of more than 70%, suggesting
severe under-reporting of small rainfall amounts).
By the way, you're right about the 0.2mm being a relic of pre-
metrication values (being closer to 0.01 inch).
> I guess my concern over this apparently trivial issue stems from the
> larger number of practices where we are strangely out of step with the
> rest of the meteorological world, and which I believe reduce the
> quality of our observational program.
>
> -- Every country in the world except Australia and some Pacific
> Islands where the met service was set up by Australia takes
> observations at 00, 03, 06... UTC. We persist with 9am, noon... local
> time, which is 23 UTC in the east, 23.30 UTC in SA/NT, and 01 UTC in
> WA. From what I have been able to work out, this is a historical
> remnant from the days when the local Post Offices did most of the
> reading, and 9am and 3pm were convenient times to get the first obs of
> the day when the staff arrived, and the last obs of the day in time
> for the Bureau to process before Bureau staff left for the day.
The 0900 observation time originated because the weather observation
was originally the telegraph test message for post offices, as you
suggest. Not sure about the origins of the 1500 observation - you
could well be right, especially in the early days.
> -- Every country in the world except Australia and NZ retain their
> observational schedule on 00, 03.. UTC during daylight saving. We
> stick to clock time, so that suddenly 9am becomes 8am, as it were, and
> real time measurements like temperature and humidity are not
> comparable within months that switch to or from DST, or between the
> DST and pre-DST era. Maximum temperatures for the day continue to be
> reported at 3pm local DST, which is 2pm local, and frequently before
> the day's maximum has occurred.
I seem to recall that, once again, post offices were the fly in the
ointment here (can't remember the exact logic - a 1000 local time
observation interrupting postal operations?).
> -- Every country in the world except Australia records the three major
> cllimatological parameters of rainfall, max and min temperature so as
> to most closely align them with the local calendar day. Our fixation
> with 9am results in true max and min temps often being lost during
> periods of abnormal temperature variation.
This is where I begin to disagree.
If you maintain a 24-hour observation day, it is inevitable that
there will be some situations where high minima and low maxima will
be lost. With an 0900 observation time, this most commonly occurs
when the 24-hour minimum is the 0900 reset temperature from the
preceding day. (Less commonly, the maximum is the 0900 reset
temperature the following day). However, using a 0000 observation
time - as was the case at some Australian stations prior to 1963 -
means that high minima can be lost if it has become cooler by midnight
that day. As this quite often happens after very hot nights in
southern Australia (the typical scenario is that a hot night will be
followed by a cool change sometime during the day, with temperatures
dropping by evening), such stations show a marked reduction in the
frequency of very high minima prior to 1963.
There are almost as many observation times for max/min temperature
as there are countries. The place where it is a real mess is the US;
whilst first-order stations (the equivalent of our Met. Offices)
record at midnight, climatological stations record at whatever time
they feel like - and changes in the observation time are a major
discontinuity in the climate record.
At Adelaide and Melbourne a 0000 observation time results in mean
minima about 0.3 C lower than a 0900 observation time would.
Once I've finished writing my thesis I will write a paper on this
issue.
There was a proposal about 3-4 years ago to shift the Australian
observing program onto WMO standard hours - easier now because we
don't rely so heavily on post offices. This was shelved, at least
for the time being. From the climate point of view a shift to 2100
UTC (0700 EST) in the eastern states, as was proposed, would have
been a disaster - as this is close to the time of minimum temperature
in winter (meaning just about every cold night would be double-
counted) the discontinuity in the minimum temperature would have been
around 1 C in most places, and exceeded 1.5 C in some.
(For consistency of the climate record, continuity of practices is
more critical than whether or not a practice is more 'accurate' than
any other).
Incidentally, a time of observation around 0900-1100 seems to be the
best compromise between not double-counting too many low minima and
not double-counting too many high maxima - although this is more by
accident than design.
I can see no good reason why rainfall is attributed to the day of
observation rather than the previous day (other than that changing
would require the recalculation of all monthly means, decile maps etc.).
> -- Every country in the world except Australia adopts standard, agreed
> WMO reporting codes which are either global, regional or national. We
> have not updated our national reporting code for at least the last 30
> years to my knowledge, with the result that it now has elements that
> confuse observers and cause errors (particularly in rainfall
> reporting), and completely ignores elements that are routinely
> reported elsewhere such as sunshine, evaporation, wind gustiness and
> snow depth.
I don't know a lot about coding. I think (but am not sure) that
there is some major reworking of the code gradually making its way
through the system.
> I won't go on, but I do despair at times at the conservatism and "near
> enough is good enough" attitudes that I believe are not giving us the
> quality of weather observations in this country that we could, and
> should, have.
Conservatism and continuity can often be two sides of the same coin,
of course.
If it were my decision alone, what I'd probably do is:
- retain the 0900 observation time for max/min temperatures and
rainfall
- aim towards recording hourly observations (initially at Bureau-
staffed stations and AWSs) and report internationally at the WMO
standard hours
- retain the same UTC observing times (one hour later in local clock
time) during daylight saving
Blair Trewin
> --
> Laurier Williams
> Australian Weather Links and News
> http://www.ozemail.com.au/~wbc/
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>
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014
Date: Mon, 28 Jun 1999 08:18:34 -0700
From: Lindsay [writer at lisp.com.au]
X-Mailer: Mozilla 3.0 (Win16; I)
To: aussie-weather at world.std.com
Subject: Re: aus-wx: snow in Sydney
Sender: aussie-weather-approval at world.std.com
Reply-To: aussie-weather at world.std.com
My parters mum (recently deceased) apparently saw snow falling in Sydney
in the 1940's, she was high in a building and said it floated slowly and
melted as it hit the ground.
Lindsay P.
Don White wrote:
>
> Paul...
> A SSW change that passed through Sydney around 3-4 pm on 27 July 1986
> dropped the temp to 7 degrees. The showers with the change included some
> soft hail - the process of formation is different but naturally, because
> of the cold and the soft hail the media claimed "snow".
> It was too warm for that.
> don White
>
>
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015
From: John Woodbridge [jrw at pixelcom.net]
To: "'aussie-weather at world.std.com'" [aussie-weather at world.std.com]
Subject: RE: aus-wx: SE QLD wx
Date: Tue, 29 Jun 1999 14:33:20 +1000
Organization: Pixel Components
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Hi all,
52mm for the 48 hours to 9:00am this morning at Mt. Crosby. This alone
would probably have to be close to, or exceed, the June average (which
would be well down on Brisbane's average).
John,
>From a very soggy & breezy Brisbane.
(Just like a Perth winter really, typical squally weather except it is
coming from the SE - next thing we'll be having some "coldies" just to
annoy Ira).
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016
From: John Woodbridge [jrw at pixelcom.net]
To: "'aussie-weather at world.std.com'" [aussie-weather at world.std.com]
Subject: RE: aus-wx: snow in Sydney and Brisbane
Date: Tue, 29 Jun 1999 14:44:32 +1000
Organization: Pixel Components
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Hi Anthony,
This was the day you guys took off chasing after the ASWA meeting. The
Woodridge event was caused by that small storm cluster that we watched grow
from a tiny cumulus. It was in fact most definitely pea sized hail,
falling around 2:30pm and reported as such in the evening news. Temps were
low twenties. The cell started to generate CG echoes on the Energex
lightning tracker at around 2:00pm in the Woodridge area.
John.
>snip
To throw in another variable, on the 1st of May, there was snow reported
just to the SW of Brisbane (near Woodridge). Jeff C. was telling me
about this, he was as surprised as I was! I immediately suggested that
there we saw a lot of hail that looked like snow on the ground, however
it was reported as falling.
Temperatures would have been in the low twenties, but under cloud, in
the mid-high teens - under precip, possibly even close to 12-13C
Could soft, melted hail have caused it to look like snow? As it seemed
far too warm for snow!!
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017
From: John Woodbridge [jrw at pixelcom.net]
To: "'aussie-weather at world.std.com'" [aussie-weather at world.std.com]
Subject: RE: aus-wx: Standards of observation (was Rain Gauge)
Date: Tue, 29 Jun 1999 15:10:30 +1000
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Oh Blair,
I actually use midnight largely because I am at home then and not at
9:00am. I have often noted that I 'lose' a warm overnight 'min' because by
midnight the following evening it is already much colder...
But what does it all really mean??
If we are talking about a 'day' then that is normally regarded as midnight
to midnight. By definition a "minimum" is the lowest temp in a given
period - therefore nothing has been 'lost' at all, the warm morning simply
wasn't the actual minimum for the period, if you get my drift.
While I on the subject though, I have often though it rather silly to take
a reading of something like rainfall at 9:00am and ascribe it to the
previous calendar day.
John.
However, using a 0000 observation
time - as was the case at some Australian stations prior to 1963 -
means that high minima can be lost if it has become cooler by midnight
that day. As this quite often happens after very hot nights in
southern Australia (the typical scenario is that a hot night will be
followed by a cool change sometime during the day, with temperatures
dropping by evening), such stations show a marked reduction in the
frequency of very high minima prior to 1963.
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018
X-Sender: kburrows at saserver
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Date: Tue, 29 Jun 1999 15:30:29 +0900
To: aussie-weather at world.std.com
From: Kevin Burrows [k.burrows at bom.gov.au]
Subject: RE: aus-wx: Standards of observation (was Rain Gauge)
Sender: aussie-weather-approval at world.std.com
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At 15:10 29/06/1999 +1000, John wrote:
>While I on the subject though, I have often though it rather silly to take
>a reading of something like rainfall at 9:00am and ascribe it to the
>previous calendar day.
Rainfall is recorded on the day it is measured, as is minimum temperature.
It is only the maximum temperature that is transfered back to the previous
day since the maximum generally occurs in the afternoon.
In the climate are of BOM we are always careful to advise clients of the
period over which extremes or totals are recorded.
Kevin Burrows
*********************************************************************
* Kevin Burrows * *
* Meteorologist * PO Box 421 *
* Climate and Consultative Services * Kent Town *
* South Australian Regional Office * South Australia 5071 *
* Bureau of Meteorology * *
* * Phone: (08) 8366 2691 *
* internet: k.burrows at bom.gov.au * Fax: (08) 8366 2693 *
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019
From: wbc at ozemail.com.au (Laurier Williams)
To: aussie-weather at world.std.com
Subject: Re: aus-wx: Standards of observation (was Rain Gauge)
Date: Tue, 29 Jun 1999 07:43:24 GMT
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Blair, Kevin and John,
Thanks for your posts on my admittedly rather provocative
contribution. It was done more to stimulate debate on a
little-discussed issue (outside the Bureau) rather than with any
malice.
Some thoughts:
On Tue, 29 Jun 1999 14:16:45 +1000 (EST), Blair Trewin
wrote:
>If you maintain a 24-hour observation day, it is inevitable that
>there will be some situations where high minima and low maxima will
>be lost. With an 0900 observation time, this most commonly occurs
>when the 24-hour minimum is the 0900 reset temperature from the
>preceding day. (Less commonly, the maximum is the 0900 reset
>temperature the following day). However, using a 0000 observation
>time - as was the case at some Australian stations prior to 1963 -
>means that high minima can be lost if it has become cooler by midnight
>that day. As this quite often happens after very hot nights in
>southern Australia (the typical scenario is that a hot night will be
>followed by a cool change sometime during the day, with temperatures
>dropping by evening), such stations show a marked reduction in the
>frequency of very high minima prior to 1963.
>
Would a fair bit of this problem be removed by reading minimum for the
24 hours to 0000z and maximum for the 24 hours to 1200z?
Kevin wrote:
>On the subject of the time at which maximum and minimum temperatures
>and daily rainfall are recorded. The WMO suggest that these items are
>reported on the first observation at or after 00z and 12z. The problem is
>that these times do not always correspond with the daily cycle. If we go
>by local time its a bit difficult to get observers up at midnight to take
>observations. Many observers take observations as part of their normal job
>and get paid for out of hours observations. Introducing midnight
>observations would be extremely expensive.
and Blair wrote:
>There are almost as many observation times for max/min temperature
>as there are countries. The place where it is a real mess is the US;
>whilst first-order stations (the equivalent of our Met. Offices)
>record at midnight, climatological stations record at whatever time
>they feel like - and changes in the observation time are a major
>discontinuity in the climate record.
>
I think this is the Co-operative Observers Network, or somesuch name.
My understanding of the US system is that they recognised some years
ago that weather reporting could be organised into two categories of
quality: the first-order stations (normally, but not always
professionally manned) where accuracy of readings, visual observations
and timing could be 100% relied upon; and all the rest, where
standards would vary according to the weather savvy and diligence of
the observer. I think an important point is that they recognised the
value of the "amateur" observer, despite the limitations that working,
sleeping and having a life place on maintaining a quality
meteorological record.
What this separation did was to allow the maintenance of tight, and
possibly different, standards at the first-order stations, and
determination of those standards by meteorological and climatological
needs, while allowing somewhat looser standards for co-operative
observers. Thus, the first-order stations perform obs at times that
ordinary mortals may find difficult.
This seems to encapsulate the dilemma. Do you maintain one standard
throughout the system so as to maintain continuity across the record
both in space and time, even though that standard must be degraded to
allow for limitations imposed by one part of the network? Or do you
split the network into elements of differing, and possibly less
comparable, quality?
>Once I've finished writing my thesis I will write a paper on this
>issue.
>
I look forward to it!
>There was a proposal about 3-4 years ago to shift the Australian
>observing program onto WMO standard hours - easier now because we
>don't rely so heavily on post offices. This was shelved, at least
>for the time being.
Does anyone know why it was shelved? Obviously, any change will cause
problems for some but open up opportunities in other directions. It
would be interesting to know both the problems and opportunities that
were identified.
>From the climate point of view a shift to 2100
>UTC (0700 EST) in the eastern states, as was proposed, would have
>been a disaster - as this is close to the time of minimum temperature
>in winter (meaning just about every cold night would be double-
>counted) the discontinuity in the minimum temperature would have been
>around 1 C in most places, and exceeded 1.5 C in some.
>
Understandably. It seems strange that 2100 rather than the more
appropriate (and standard) 0000z was proposed. Possibly the problem
that the few one-obs/day stations would then have had with their
maximum temps ruled out 0000z, again highlighting the compromise in
having one standard to cater for a diverse network.
>I can see no good reason why rainfall is attributed to the day of
>observation rather than the previous day (other than that changing
>would require the recalculation of all monthly means, decile maps etc.).
>
I guess that by the time you get to 9am, the total is virtually split
between days anyway so there's little benefit in crediting the total
to the previous day.
The 9am (or 0000z if we moved to WMO times) 24-hour rainfall
observation does have the advantage that readings from the larger
network become available at what's probably the best time for
processing and dissemination. Basing the 24 hour fall on 9pm (or 12z)
could be interesting -- whilst it may lose some observers who read the
rain at work, it would gain others (like John) who read the rain at
home but are at work at 9am.
The UK (and I think European) alternative could be worth consideration
-- read the rain 12-hourly to 9am and 9pm. Some stations will only be
able to report at one or the other, but many (and most synoptic
stations) would be able to report at both.
John wrote:
>If we are talking about a 'day' then that is normally regarded as midnight
>to midnight. By definition a "minimum" is the lowest temp in a given
>period - therefore nothing has been 'lost' at all, the warm morning simply
>wasn't the actual minimum for the period, if you get my drift.
Yup. Here's another point to consider. Tmax and Tmin are useful
snapshots of the extremes of a day's temperatures, and are practical
in the sense that an observer simply has to set two purpose-designed
thermometers daily. But the advent of electronic means of weather
monitoring should allow us to acquire and better encapsulate much more
information about the character of a day's temperature, rainfall and
other variables.
Some examples of what I mean. Mean temperature is given as the average
of Tmax+Tmin, but you get a more accurate figure by dividing 24 hourly
readings by 24. Many growers would find the number of hours exceeding
certain temperature limits by x degrees more useful than knowing that
there were 5 days exceeding 30C. Rain hours would be a more useful
(and less misleading) concept than raindays.
Kevin wrote:
>Its important for climate change studies to maintain a standard time of
>observations and this is one reason for our reluctance to change. When you
>looking for small changes in temperature over long periods you dont want
>the data set corrupted by changes introduced by changes of instrument, site
>or observation time.
Agreed, and a sound reason for not moving the observational program
with daylight saving. The number of stations in Austalia that has such
a quality time series of data is small, and has been recognised as a
specific subset described on the Bureau's website -- I think there are
about 100. I'm sure Blair's work will cast further light in this area,
too.
Right now, however, we must be experiencing the largest change to
physical siting of stations in the Bureau's history, with hundreds of
AWS's, often replacing manned stations in different locations, and
town-based sites being moved, in some cases into completely different
microclimates, as developments threaten exposure. Isn't this the time
to introduce any other discontinuities that would improve
observational practice long-term, while taking separate action if
necessary to protect the validity of long-term records?
--
Laurier Williams
Australian Weather Links and News
http://www.ozemail.com.au/~wbc/
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020
X-Originating-Ip: [210.84.7.46]
From: Paul Graham [v_notch at hotmail.com]
To: aussie-weather at world.std.com
Subject: aus-wx: Tornado Encounter...
Date: Tue, 29 Jun 1999 01:10:34 PDT
Sender: aussie-weather-approval at world.std.com
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Here is an interesting account of a tornado near Melbourne around 1970:
http://www.drdisk.com.hk/tornado.htm
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021
From: "Paul Rands" [prands at healey.com.au]
To: "aussie-weather at world.std.com" [aussie-weather at world.std.com]
Date: Tue, 29 Jun 1999 18:31:14 +1000
X-Mailer: PMMail 98 Standard (2.01.1600) For Windows NT (4.10.67766222)
Subject: Re: aus-wx: Fog in Sydney
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Reply-To: aussie-weather at world.std.com
Hi there
>There was a thick fog in sydney last night. At least, there was in my part
>of sydney ( the hills in the north west). I got up at 2am and couldn't see
>the other side of the road, which is less than 20 metres away, even though
>there are street lights. It was all gone by 6am this morning though.
>On another topic, it has rained for the last eight days here, about 30mm in
>total, not a lot of rain. The total for this month is about 55mm so far,
>the average for June is 100mm.
>
at 8 AM on the way to work here in Sydney on the Great Western Highway from St marys to Eastern Creek there was thick fog with visibility of
about 50 metres. Was a slow drive to work today. It's drizzling now, so I don't what to expect tomorrow morning
>From the mind of Paul Rands
Personal Site: http://members.xoom.com/paulrands/
Canberra.Net: http://www.healey.com.au/~prands/canberra/
E-mail: prands at healey.com.au
ICQ: 141094
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022
From: "Jason" [kevans at kisser.net.au]
To: [aussie-weather at world.std.com]
Subject: aus-wx: Cyclone Thelma Report
Date: Tue, 29 Jun 1999 16:47:46 +0800
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Hi All :)
Found this TC Thelma report on WA's BOM forcast page......
Heaps of info here including sat pics, radar images and track map.
http://www.bom.gov.au/weather/nt/inside/thelma/
Sunny Warm weather continues here with a max of 29C today :)
26C expected tommorow with Gusty E'ly winds.
Jason Aka JuNgLeJiM waiting patiantly for the next cyclone season to rock around....will November ever come ? :P
Karratha W.A
http://www.kisser.net.au/kevans/weather/
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023
X-Originating-Ip: [203.25.186.115]
From: Kevin Phyland [kjphyland at hotmail.com]
To: aussie-weather at world.std.com
Subject: Re: aus-wx: Standards of observation (was Rain Gauge)
Date: Tue, 29 Jun 1999 20:05:21 EST
Sender: aussie-weather-approval at world.std.com
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Hi Laurier,
I've just finished putting up my new rain gauge (which I got as a Christmas
present!) due to the difficulty in finding an appropriate sheltered spot.
I agree with you about the strange times that we take measurements but are
you suggesting that we take daily measurements at midnight, say, to coincide
with local dates? What is the recommended time for taking a "daily"
recording?
Cheers,
Kevin from Wycheproof.
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024
Date: Tue, 29 Jun 1999 09:52:49 +0200
From: Tom Johnstone [Iain.Johnstone at pse.unige.ch]
Subject: Re: aus-wx: snow in Sydney
X-Sender: johnston at fapse.unige.ch
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At 10:32 29/06/99 +1000, you wrote:
>
>My obs of "warm" snow in since I started watching such stuff
>from 1973 follows. But I can imagine that given the right
>conditions, obs of "snow" in Sydney could go to quite high
>temps. Maybe not as high as 6C but maybe 4C to 5C;
Hi all,
This is a good chance for me to stop lurking and join in the discussion. I
am actually writing from Switzerland, where I'm currently living, but
originally come from Perth. And next year I'll be living in Wisconsin
(Tornado country??). I hope people don't mind a semi-outsider posting here,
but it's nice to compare weather in Australia with what I see over here.
Anyway, I have seen snow fall here in Switzerland at very high
temperatures, albeit melting on impact. This has happened generally in late
spring here in Geneva, altitude 350m. From memory, it usually comes about
when, following a warm spell, a cold front comes in and hits the warm air.
The snow starts falling when the air temperature is very high, although the
air temperature does drop rapidly thereafter. Especially at the start, the
falling flakes are very large. Not like any snow I saw when I was in the
Australian skifields though.
Does anyone know the melt rate (per metre for example) for a snow flake
falling through the air as a function of temperature and humidity? And what
is the normal range of snow flake sizes when it starts falling? That way we
could make an estimate of how far a flake could fall before melting, no?
(Just a naive thought - I don't profess to knowing much about weather).
Tom
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025
Date: Tue, 29 Jun 1999 21:01:29 +1000
From: Keith Barnett [weather at ozemail.com.au]
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To: aussie-weather at world.std.com
Subject: Re: aus-wx: Not much rain south of Illawarra
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Reply-To: aussie-weather at world.std.com
And the drought index is slowly creeping up..it will reach 80 by the
weekend if I don't receive more than 5mm of rain from this next cold
front...
Michael Thompson wrote:
>
> In a repeat of almost the whole of this year so far the Illawarra seems to
> be the stop point of rainfall. All weekend I could see blue cloudless sky to
> the far south, whilst very light showers fell here. This is not the first
> time I have seen this !
>
> The south coast whilst certainly not drought affected is in need of a good
> drink.
>
> Michael Thompson
> http://thunder.simplenet.com
>
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026
From: "Matthew Piper" [mjpiper at ozemail.com.au]
To: "Aussie Weather Mailing List" [aussie-weather at world.std.com]
Subject: aus-wx: Davis Weather Monitor II
Date: Tue, 29 Jun 1999 22:00:52 +1000
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Hi Everyone,
Does anyone know of a place other than Australian Geographic which sells the
Davis Weather Monitor II and the Weatherlink software that goes along with
it. I am thinking of buying one but would like to shop around for the best
price. Any help would be most appreciated.
Thanks,
Matthew Piper
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027
X-Originating-Ip: [203.27.197.6]
From: Rod Aikman [raikman at hotmail.com]
To: aussie-weather at world.std.com
Subject: aus-wx: Standards of observations
Date: Tue, 29 Jun 1999 22:15:28 EST
Sender: aussie-weather-approval at world.std.com
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Hi everyone,
Just been reading your comments re observation standards, and I
thought that I would add this one.
There is also a problem with recording the previous day's maximum
temperature at 0900 the following morning. The mercury column above the
constriction of the maximum thermometer will contract as the temperature
falls from the maximum. This negative error could be from 0.1 - 0.2 degrees,
particularly if a cold morning happens to follow a warm or hot day. In the
'Handbook of Meteorological Instruments' (Brit. Met. Office publication) a
formula is given for the correction of the discrepency, based on the
temperature difference, and the co-efficient of expansion of mercury. I
wonder if any observer or the Bureau ever applies this correction to the
maximum temperatures?
Rod Aikman
Bendigo Vic
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028
From: "John Graham" [gorzzz at one.net.au]
To: [aussie-weather at world.std.com]
Subject: Re: aus-wx: Davis Weather Monitor II
Date: Tue, 29 Jun 1999 23:05:32 +1000
X-Mailer: Microsoft Outlook Express 5.00.2014.211
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----- Original Message -----
From: Matthew Piper [mjpiper at ozemail.com.au]
To: Aussie Weather Mailing List [aussie-weather at world.std.com]
Sent: Tuesday, June 29, 1999 10:00 PM
Subject: aus-wx: Davis Weather Monitor II
> Hi Everyone,
>
> Does anyone know of a place other than Australian Geographic which sells
the
> Davis Weather Monitor II and the Weatherlink software that goes along with
> it. I am thinking of buying one but would like to shop around for the best
> price. Any help would be most appreciated.
>
> Thanks,
>
> Matthew Piper
Try Solar Flair in Vic (03) 59684863....that's where I got mine from.......
Cheer's,
John from Ballina
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| Document: 990629.htm
Updated: 24 July 1999 |
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