Jimmie Phang
To: "'synoptic_discussion@bom.gov.au'" <synoptic_discussion@BoM.GOV.AU>
Subject: [synoptic_discussion] W1 hits to significant weather.
Dear all

My apologies because there's no science or meteorology involved this
occasion.

In the month of Feb 2002, there was 143,322,949 hits on our website(combined
general and radar), record for our website The average daily hits for
general bom.gov.au was 1,606,575 and radar 3,512,101.

The number of hits for dates 01-08, 15-17 and 25-26 was above average, I
would really appreciate if anyone can help me put the hits to weather
events. Thank you all.

Regards
Jimmie PHANG

Rob Webb
Hi Jimmie

Sydney had a big supercell on the 16th of Feb that brought about 8500 SES
jobs, that may explain some of the hits (On a Sunday I think).

We also had another fairly big outbreak on the 8th that included Sydney and
people knew about for some time in advance. Not much damage but pretty
spectacular.

Hope this helps.
Rgds
Rob Webb
NSW Severe Weather

Alan Sharp
Jimmie,

I can tell you that the first week of February had three significant events.

Firstly Severe Tropical Cyclone Chris formed north of WA on the 3rd, crossing the coast between
Port Hedland & Broome early on the morning of the 6th
Secondly there was significant rain that caused flooding and consequential traffic chaos in and
around Sydney on 4th & 5th
There was also severe thunderstorms and gusty damaging winds in and around Melbourne about 7th

Here is an extract from an e-mail I sent out to the regions & COSB the week following the event:
....
Tuesday (2.6 Million) did exceed Monday (2.2 million) in Web hits and Radar hits

In fact on Every Weekday last week the number of non Radar hits exceeded 2 million
whereas the previous record was 1.8 million.

Also the previous record of radar hits (4.0 Million on 31/12/01) was exceeded on
seven of the first eight days of February with a peak of 6.75 Million on Friday 8th.
TC Chris did play a significant role in the normal web statistics - but would be about
equivalent with the other significant weather events in the week that is the flooding
in Sydney and the stormy night in Melbourne. It was not such a drain on resources
as the most popular product from Chris - the threat map - was much smaller in size
than the observations graphics for the major capitals. All contained graphics images.

For radar TC Chris was less significant when compared with the demand for information
from Sydney, Melbourne and Brisbane.

Last week was a record week due to to main reason - plenty of significant weather events
including events affecting the three largest capitals and TC Chris and the long term growth
factor. The servers probably were struggling to keep up, will they be ready for next season?
....

I will leave it to someone else to find out what happened in the other two periods

Alan Sharp

Noel Davidson
G'day Folks,

With regard to Jimmie Phang's enquiry about sig weather, we've often thought it would be
really nice and useful to have a data base of such events. Similar to the TC best track
data set, but for heavy rain, flash floods, 'bombs', severe storms, bush fire weather, major
forecast failures, other (?).
The archive would be very useful for forecasting, climatological studies and research.
Maybe this information is available in the Regions (??) in electronic form (??).
If not it would be valuable to assemble such an archive. There needs to be
more thought
on how to define the events and what info to include in an archive, but
even very basic documentation would be good. The Regions would need to provide the
basic info, which could be collated by some central branch, maybe Services Policy,
NCC or NMOC. Yeah, more work for alraedy over-loaded people - but how interesting
would it be even for the data gatherers, and the long-term benefits are
potentially great.

With the currently available tools (NCEP re-analysis data set, LAPS, diagnostic
programs, time series display from the DP, etc, and data from emerging observational technologies),
a systematic look at all types of severe weather events is possible.

The Guru and I have often pondered about diagnostic and prediction studies of such infrequent
but critical events. Just to document the circulation changes, prediction skill, mesoscale
initialisation issues, forecast deficiencies, and to describe the dynamics would be really interesting and
exciting. In fact, as extremely low, almost zero priority projects we have started to do this :
Tracy, Ash Wednesday, Katherine, Wollongong, Laverton Floods, Melbourne flash floods of 1972.....
Of course, anyone who has an interest in collaborating on, or analysing such events could
use the data set and is/would be encouraged to do so.

What d'ya reckon?

Noel Davidson

Andrew Tupper

Noel,
What about the Significant Weather Summaries?

http://web.bom.gov.au/spb/spawspo/public/sigws.shtml

Andrew Tupper

Blair Trewin
As those of you who are AMOS members will know, I write a one-page article
for each AMOS Bulletin featuring a notable surface chart from the past and a
description of associated events. These aren't particularly technical but
still might be of interest. I've tended to steer away from the really famous
events (such as Cyclone Tracy or Ash Wednesday) on the grounds that a lot
has been written about them already. I also tend to favour events which have
impacts on multiple states (for example, the one which is just going to
press covers the intense SA anticyclone of mid-July 1976, which brought
record low minima to SA and the southern NT and record high July maxima to
much of south-western WA).

I don't have any objections in principle to these going on the web somewhere
if someone wants to put them there. There are 38 articles in the series and
all should still exist on my hard drive somewhere.

Blair

Milton Speer
Noel and others,

FYI, In regard to heavy rain and/or wind strengths and/or large swells from lows on/near or even well seaward
of the NSW coast that produce significant impacts, some work is currently underway in the NSW region to
better archive such events. There have been some very useful climatologies documented (e.g. Hopkins and
Holland, J of Climate., April 1997), and in that case, based on rainfall thresholds along the coast, but it is felt
(just as you have expressed Noel) that there is a need for a more comprehensive, regularly updated
archive of such events. I guess the motivating factor in getting this project going was a large number of enquiries
in the NSW Region resulting from the impacts of the March 2001 low on the NSW north coast.

M

Jimmie Phang

Following from Noel's to Blair's comments/suggestions, presenting all this
information on the WWW will be a worthwhile exercise. Everyone will be
benefit from it.

I will make arrangements for this to happen, but not in the immediate
future. Keep in touch.

Regards
Jimmie PHANG

Jeff Kepert

Noel

There was a study done in NSW (in the mid-80's?? by consultants?? never formally published??) which
resulted in a catalogue of all the "significant" east coast lows over the past century ... I don't know if the
list has been kept up to date since. It would have been cited in Linda Hopkin's PhD thesis.

The monthly notable weather summaries (or whatever they're called) must also have a stack of useful
stuff in, albeit unorganised.

Clearly such things are very useful and it would be great if they were readily available, maintained,
and electronic.

Perhaps the upcoming weather services conference could be an opportunity to nut out a list of what would
be useful/feasible?

Jeff

Ted Williams

Hello all,
               for everyone's info' the monthly significant weather
summaries back to January 1996 are on the internal web at -

http://web.bom.gov.au/spb/spawspo/public/sigws.shtml
and the external web at -
http://www.bom.gov.au/inside/services_policy/public/sigwxsum/sigwmenu.shtml

Happy browsing
Cheers
Ted

Milton Speer
Jeff,
FYI That east coast low study you mention was done, in part, by Rosea Kemp, currently in NSW CCS, when she
was a consultant in the eighties. The study concentrated on damage from storm surges and it will be
incorporated into the setting up of the ongoing archive I mentioned previously.

Milton

Rosea Kemp

Thanks Milton, (for name and affiliation) and Jeff (content) for your citations!  These are the ONLY ones
of which I am aware inmeteorological 'literature' regarding these studies. For those who are interested, a
little background.

Fresh from the Bureau in Jan 1980, I (out of the Bureau for family reasons) and the late Don Douglas
(who some older folk may remember as a brilliant and war-time experienced 'seat-of-the-pants' Meteorologist,
and who had just retired) were dumped into a consulting job to determine return intervals, of high water
levels (presumed to be by surge) atCoffs Harbour.  This was a study initiated by the Public Works
Department (PWD) for Coastal Zone Management.  There was no instrumental record whatsoever, so the
job had to be waves from weather. Not really having much of a clue as to how to go about the job, we
figured it best to do the whole NSW coast for onshore winds, thinking we might discover some consistency.
We went back as far as we felt confident of getting a reasonably complete picture.  The result, some 9
months gestation later, was a climatology of ONSHORE windstorms in NSW for a hundred years published
in 1985.  Rainfall was NOT in our brief,but as a final measure we correlated every known NSW flooding event and
found that every single one was already covered in the data, including the possibility of major runoff corresponding with onshore wind, wavesetup, swell, storm surge and/or inverse barometric effects.

The publication arrived here at the bureau without attribution (via the PWD), and the climatology forms the
backbone of the NSW RFC Large WaveDirective, as well as being used in other ways.  I might also add that
the coastal engineers were ecstatic at the scope of the study, and have used it and referenced it many times.

Attribution (or lack of) is not so surprising, as publications were pretty anonymous. For those who want a reference:

Public Works Department  COASTAL BRANCH
ELEVATED OCEAN LEVELS
STORMS AFFECTING N.S.W. COAST 1880-1980
prepared by BLAIN BREMNER & WILLIAMS PTY LTD Consulting Engineers
in conjunction with WEATHEREX Meteorological Services Pty Ltd
Report No 85041                           December 1985

For the second Report, we looked at the continuum, 1980 to 1985.  We found that, as expected in the original study, meteorologically we would have missed many brief swell situations from very distant major systems which directed a tiny window of major swell waves onto the coast at a localised point.  But essentially, the meteorological study was
mirroring coastal buoy measurements for all significant storms.

The reference for that one:
Public Works  COASTAL BRANCH
ELEVATED OCEAN LEVELS
STORMS AFFECTING N.S.W. COAST 1980-1985
prepared by
LAWSON AND TRELOAR PTY.LTD. Coastal, Ocean and Port Consulting Engineers
in conjunction with
WETHEREX Meteorological Services
Report No 86026                           August 1986

All I can guess about these works  is that they were aparently anonymous and not published in meteorological literature, so were virtually unknown.

We intend a NSW study to update the climatology - in the met AND engineering context.

Cheers

Rosea Kemp