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#983941 - 13/04/2011 21:57 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
1008 hPa, 77% Humidity, 12 C.

Has started raining...


Edited by -Cosmic- (naz) (13/04/2011 21:57)

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#984796 - 17/04/2011 12:13 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Originally Posted By: -Cosmic- (naz)
1008 hPa, 77% Humidity, 12 C.

Has started raining...

1.9 mm total over 2 days...negiligible change in flow; remains steady.

The Global Spectral Model Run (MRF) from NOAA shows a possibly major rainfall event towards the end of the month (forecast 00Z15apr2011 to 12Z30apr2011 PRATE 1000 and PRMSL 1000). This may or may not have been an anomlay (the next run does not appear to indicate the same rainfall totals, ~40-50 mm).

A moderate flow is expected from this rain at this stage (~1.6 units). September 3rd 2010 flow was over 20 units. The pressure (MRF MSLP) is expected to drop markedly to 1006 from around 1021.

Flow has not been significant or even moderate since about 0.47 units was estimated on the 23rd of March this year.


Edited by -Cosmic- (naz) (17/04/2011 12:16)
Edit Reason: Clarify

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#984829 - 17/04/2011 16:00 Re: Streamflow Observations [Re: Seira]
kimballthurlow Offline
Cloud Gazer

Registered: 26/03/2011
Posts: 11
Hi Cosmic-naz,
I understand the BOM responsibility (and your recent posts seem to amplify that) for forecasting and warnings on an Australia-wide and regional basis. Have we become a sufficiently large and sophisticated community where a specialist division of the BOM could be set up to research, understand and monitor the more local ramifications of intense rainfall and other weather events of significance in real-time? I am particularly interested in the usefulness or otherwise of the typical engineering calculation for volume/speed determined from intensity. For example, you talk about dry under-soil contributing to a different rate of run-off. It appears to me that such studies need to occur on a national basis with professional integrity and government support. regards, Kimball

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#984906 - 17/04/2011 21:55 Re: Streamflow Observations [Re: kimballthurlow]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Originally Posted By: kimballthurlow
Hi Cosmic-naz,
I understand the BOM responsibility (and your recent posts seem to amplify that) for forecasting and warnings on an Australia-wide and regional basis. Have we become a sufficiently large and sophisticated community where a specialist division of the BOM could be set up to research, understand and monitor the more local ramifications of intense rainfall and other weather events of significance in real-time? I am particularly interested in the usefulness or otherwise of the typical engineering calculation for volume/speed determined from intensity. For example, you talk about dry under-soil contributing to a different rate of run-off. It appears to me that such studies need to occur on a national basis with professional integrity and government support. regards, Kimball

Firstly, thanks for the your interest smile .

This is a bit of a long-winded explanation…so bare with me smile

I believe we have the resources to begin the process of forming such divisions associated with specialist monitoring, however the science (and in the case of the basis of this thread, streamflow monitoring) is still very much, regionally, in its infancy. There has been a particular major focus recently on understanding the basis of primary contributors to Adelaide Hills catchments (e.g. groundwater in the Willunga Basin south of Adelaide), and more broadly other larger catchments such as those of the Murray-Darling. There are many variables involved in an accurate understanding of groundwater-surface-water related system, suffice to say that there is now the National Centre for Groundwater Research and Training (NCGRT) established at Flinders University.

While groundwater is very important in contributing to the likelihood of significant surface-water events, and likely conditions conducive to major rainfall events, I acknowledge the issue to more how funding is spent and prioritised. Much of it, I believe, goes to water resource management, wherein modelling is conducted based on in-field observations, or quality-controlled datasets. The issue then becomes one of environmental change…which, to say the least, can be profound, both agriculturally and horticultural (I have noticed changes in rainfall even locally within the Central Adelaide Hills region with increasing population and vineyards becoming established).

Since vegetation have been planted along many catchments in the Hills, runoff has become more manageable…however it is and was the initial clearance of vegetation and reduction in available native habitat – environmental change during and after settlement – which may have likely caused major degradation; this is well documented:

“Assessing the impacts of dryland salinity on South Australia’s water resources”
CSIRO Land and Water, Technical Report, 9/00, Jolly et al. 2000.

Having done some research on Catchments in the Hills…I believe that on occasion environmental changes may not be sufficiently account for, with the likely causes of these being unknown.

My main concerning is consistency, even if what is being monitored is not accurately calibrated, consistent records (using the same process) can be kept at a bare minimum. It makes it far more manageable and straight forward to correct if this done. However, there are some environmental changes which are the focus of our research, so to say regional (or national) change is an “issue” is quite a relative notion.

Hope that goes some way towards shedding light on these things for you smile .


Edited by -Cosmic- (naz) (17/04/2011 21:59)

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#984938 - 18/04/2011 06:24 Re: Streamflow Observations [Re: Seira]
kimballthurlow Offline
Cloud Gazer

Registered: 26/03/2011
Posts: 11
HI Cosmic-naz,

Thanks for that insight.

I have a particular interest in that sort of thing, as it relates to torrents despatched recently in SE Qld., with subsequent loss of life.

Anyway, there is a Commission of Enquiry here in Queensland, no doubt there will be some professional assessment of what can be done in the future with regard to understanding rainfall input and subsequent stream flows. A useful warning system may result.

regards
Kimball

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#985482 - 21/04/2011 12:09 Re: Streamflow Observations [Re: kimballthurlow]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Originally Posted By: -Cosmic- (naz)
The Global Spectral Model Run (MRF) from NOAA shows a possibly major rainfall event towards the end of the month (forecast 00Z15apr2011 to 12Z30apr2011 PRATE 1000 and PRMSL 1000). This may or may not have been an anomlay (the next run does not appear to indicate the same rainfall totals, ~40-50 mm).

A moderate flow is expected from this rain at this stage (~1.6 units). September 3rd 2010 flow was over 20 units. The pressure (MRF MSLP) is expected to drop markedly to 1006 from around 1021.

It seems there may be an increasing likelihood of significant rainfall on or around the 29th of April…

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#985484 - 21/04/2011 12:25 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
It's not 12 pm CST (Central Standard Time) yet...but I am suspicious there is a risk of thundery showers/rain this afternoon.

...particularly for the Lower Southeast.

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#985974 - 24/04/2011 14:23 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
22/04/2011:

2.4 mm overnight. Currently 21 C (12:10 pm) with a light SSWerly. Mediocre Cumulus about. Pressure: 1011 hPa.

23/04/2011:

The peak in rainfall (MRF) circa beginning of next month is still there. Pressure: 1018 hPa (7 pm).

24/04/2011:

The peak in rainfall is now visible in the 7-day run (GFS)…in fact two peaks around the 29th. The first peak reaches almost 6 mm, the second about 9 mm. The peaks are the only ones visible on the graph. The pressure is expected to take a nose dive around the 28th, dropping about 5 hPa…the streamflow (runoff) increases by about 6-fold (to a moderate flow)…soil moisture (top layer) jumps abruptly, by about 4% (if I’ve interpreted that accurately).

Most impressively of all the precipitable water (PWAT) climbs gradually (from today) to almost 28 kg/m2, before dropping sharply on the 29th to reach 12 kg/m2 by the 30th.

All the above (notes 23rd-24th) seems to be pointing towards severe weather in a short space of time (maybe a day or two).


Edited by -Cosmic- (naz) (24/04/2011 14:25)
Edit Reason: Corrections

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#985975 - 24/04/2011 14:29 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Can anyone correct me on this, was I seeing things:

The temperature was only 16 C yesterday (1 C overnight to today)...I thought I saw sleet falling yesterday (very overcast, still)!

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#986281 - 27/04/2011 13:20 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Indications are that there is significant weather on the way, starting the 29th.

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#986317 - 27/04/2011 18:40 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Rainfall: expecting several peaks including (one or more) 15-20 mm.

Temperature: average (2-metre) below 20 C starting 30th, below 16-18 C thereafter.

0-10 cm soil moisture: jump from 0.11 to 0.18, maintained (i.e. not temporary).

Precipitable water: likely to be around 14 kg/m2 tomorrow, then jumps to 28 kg/m2 by 30th, maintained until the 2nd.

Streamflow (runoff): a moderate peak is expected on or around the 30th of April.

Today’s max temp: 29!
Yesterday max temp: 28!

Forecast temp 4th May: around 16!

Pressure: change is not as noticeable…gradually fall then gradual rise, partially consistent with a system from the west, more so a system from the west combined with a pre-frontal trough and Northwest Cloud band formation.

I suspect there may be an upper-level trough involved as I’m talking (above) about surface or near-surface pressure, not the upper levels.

One last thing to note: on the GFS ACCESSG + 144 HRS Mon 2nd May 2011, the 5400 Thickness Line is clearly over Adelaide.


Edited by -Cosmic- (naz) (27/04/2011 18:44)
Edit Reason: Corrections

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#986329 - 27/04/2011 19:42 Re: Streamflow Observations [Re: Seira]
Max Record Offline
Weatherzone Addict

Registered: 18/04/2009
Posts: 1659
Loc: Adelaide
Good call on your post from the 21st! smile Not that we don't exactly know how much there will be from then on; it is at least precipitation. And also, don't think you arouse much interest in this thread - I regularly read this. I just don't respond because I don't want to sound dumb. blush wink
_________________________
2017: 478.0mm
2016: 680.0mm
2015: 392.8mm
2014: 450.4mm
2013: 470.6mm
2012: 426.8mm
2011: 518.2mm
2010: 549.4mm
2009: 459.2mm
Yearly Average: 460mm

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#986342 - 27/04/2011 20:42 Re: Streamflow Observations [Re: Max Record]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Originally Posted By: Max Record
It is at least precipitation.

Yes...looking forward to it smile !

Originally Posted By: Max Record
And also, don't think you arouse much interest in this thread - I regularly read this. I just don't respond because I don't want to sound dumb. blush wink

I'm ok with not much interest to an extent...I simply provide information and some possibilities (or probabilities) based on that information.

Also, I have a thing that if no one looks into this stuff, how are we going to have a better understanding of what goes on in the future.

If you weren’t there to plot it out, how can you claim to know what went on…it also helps to have a computer model or two nearby wink smile .

Lastly, there is no such thing as a dumb question, only the one that everyone wants to ask but no one will lol smile .

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#986889 - 30/04/2011 15:31 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
There is a trough situated overhead, extending all the back to northwest WA, and down past TAS. All that is (seems) needed is an increase in the dewpoint and for a “kink” to develop in the trough (to the north), and tomorrow’s forecast of 10-20 mm is looking increasing likely.

You almost have to look all the way back to the Western Indonesian Archipelago to see what’s going on.

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#987148 - 02/05/2011 14:39 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
The GFS (AVN) was accurate to within less than a millimetre (6.5 mm to 6.7 mm actual), to within the last 3 hours of the forecast for yesterday.

No significant/moderate runoff.

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#987590 - 04/05/2011 20:20 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Streamflow has been increasing gradually, audibly over the last 3 days...this is very unlikely to be a consequence of 9.9 mm falling over a period 29/4/11 to 2/5/11...it's more likely a consequence of sub-surface (groundwater) flow, the pressure having increased from 1009 hPa on the 2/5/11 to 1018 hPa today.


Edited by -Cosmic- (naz) (04/05/2011 20:23)

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#987641 - 05/05/2011 10:08 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Originally Posted By: -Cosmic- (naz)
Streamflow has been increasing gradually, audibly over the last 3 days...this is very unlikely to be a consequence of 9.9 mm falling over a period 29/4/11 to 2/5/11...it's more likely a consequence of sub-surface (groundwater) flow, the pressure having increased from 1009 hPa on the 2/5/11 to 1018 hPa today.

Now higher than 1020...

Also:

http://www.epa.sa.gov.au/xstd_files/Water/Brochure/fact1.pdf
http://www.epa.sa.gov.au/xstd_files/Water/Report/mtlofty.pdf

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#987802 - 06/05/2011 12:32 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
Unfortunately this is a little in retrospect, so it isn't really a prediction:

What looks like a cut-off low that has formed in the Bight off a frontal system...these can be the types lows that generate much of the "breaking winter rains" across Southern Australia, and in particular the Southeast.

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#987805 - 06/05/2011 12:49 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
It might be worth watching this low for a while (with the activity off the NW coast of WA) to see what happens smile .

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#987955 - 07/05/2011 12:30 Re: Streamflow Observations [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7616
Loc: Adelaide Hills
There seem to be warning signs from this system...for tomorrow.

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