I cringe every time I read these radar threads with the massive misinformation often sprouted as truth.

There may be a few radars that scan at 0 degrees, but they tend to be atop mountains.
Ambit claims that most scan at 0 are totally incorrect.
The truth is most scan at a base elevation of 0.5 degrees.

The images provided on the web are not simple base scans. They are a composite of several elevations combined together. The primary intent is to provide a constant altitude PPI image, and modern systems are also programmed to seek higher elevations in known problem permanent echo locations.
And yes, they are deliberately dumbed down because the Bureau otherwise receives endless emails about PE breakthrough.

Grafton radar is and has always been a S band radar, not C band.

The reported intensity IS NOT RAIN RATE. It is reflectivity.
The displayed intensity can only be considered as a GUIDE to rain rates, not gospel truth.
The are many ways relectivity can be converted to rain rates, all delivering different answers from the same reflectivity input value.
The difference comes about due to drop size distribution variations within rain events.
For instance, one single 3mm drop will return as much power as 729 1mm drops in a cubic metre. Guess which sample holds more water for the same dBz return? From this simple example it should become clear why thunderstorms do allegedly overread on the more accurate modern radar.

The older radars do underestimate reflectivity due to their less advanced signal processors and sampling methods.

This is an excellent online training guide: http://www.wdtb.noaa.gov/courses/dloc/topic3/lesson6/player.html

And your going to tell us something new? Truth is most here are probably aware - I don't think it really adds much here to the current discussion about the lack of radars in certain areas. If someone doesn't know radar viewing in Australia is CAPPI then you probably shouldn't be talking about the radar network. There is also the wavelength issue (why they chose a doppler C band at Yarrawonga with a storm attenuating wavelength is beyond me) and the issues that has with the attenuation of the signal are a nightmare. You also have the siting of radars which is generally fairly difficult due to the state politics.

My apologies on the Grafton radar - I thought it was done on the C-Band wave that was carried out for Wagga, Moree (Just checked the BOM website) - C bands are commonly used by the weather news stations in the US because they are cheaper but still have heavy attentuation issues. In all probability Grafton was put in as an S-Band as there was a high impact event that caused public pressure to install it.

As to the reflectivity - this should be another given. For those who aren't aware most radars are calibrated to local observation to provide such estimates - reflectivity is only moderately useful in CAPPI type scans anyway - give me GR Level 3 or full coverage any day. I certainly don't use the intensity when I am looking at storms (attentuation and radar calibration), I tend to look for radar derived structure (but thats a whole other story).

Anyway, I've gone tangential. Suffice to say that the bureau network has a number of deficiencies that should be closely thought about before diverting more money to model development. Just saying.

Sorry to have attempted to have added factual corrections to prior posts. I didn't realise that would be off topic.

The reason why C band radars are installed and in use is as you have stated.
COST EFFECTIVENESS.

Yarrawonga was not originally a doppler radar.
It was upgraded early on in the RNDSUP era with in house technology. It was chosen as an existing radar with one of the best coverages, narrow beamwidth and lack of PEs. The proximity to Melbourne was an added asset.
After the upgrade it was not allowed to operate as a Doppler till the big S1s were switched on - Politics.

Yes C band suffers attenuation, but better to have a radar than none surely?

There is a progressive introduction of more S band radars as more doppler radars come online. S band provides the added advantage of doubled nyquist velocity along with reduced attenuation, but at typically double the cost.

I agree there should be a Mallee radar. Should have been in years ago, and be up for replacement.

Perhaps the old Grafton is the new Emerald - rushed in to meet a political desire. You could be quite correct, too long ago to remember.

As for radar calibration, they are all calibrated to a defined representative signal power.
Local observation plays absolutely no part in it.
Local interpretation certainly may vary especially as we move from the tropics down to the temperate regions, but at the end of the day they are all calibrated to the same dBZ reflectivity values - never has been any different.

Sorry for my tangential offering :-/

Unfortunately there are some of us who don't know all that much about radar operations so very useful information, Zathrus! Thank you!
There are certainly still many areas of Australia that the general public need radar coverage. It surprises me that the Mallee has not got one to date as the coverage from Melbourne, Mildura or Mt Gambier is of very poor quality, because of distance. I have a question that may have already been answered previously, but is what we see on the BoM site what the BoM forecasters use?

No, but in the past yes!

The forecasters these days have access to the full volumetric data, along with other derived products such as thunderstorm prediction tracks from the volume data.

In the initial days, yes the composite PPI images as viewed on the web were all that the forecasters had access to - and the web didn't exist back then!

Having said that though, the web images do provide the basis of the national merged images used as a quick heads up before delving into more detailed products.

My apologies Zathras, was in a rather cynical tired mood last evening. Tend to forget how little people know about radar in Australia compared to the US, and sometimes forget that many of the people on this forum weren't as fortunate to have my background.

I think what annoys me about the C-band is how the bureau somehow trys to claim it is a positive thing (read the Yarrawonga description to see what I mean) - and then points out that its actually designed for light precipitation (which is really not exactly that useful as a radar product except in model assimilation). I am sure you aware the debacle with the S band doppler upgrade when it came to what the bureau asked for versus what was provided from treasury. Embarassingly NZ has shot past us - their entire network is now S band, with a combination of doppler and Dual-pol sites as well in their network. They actually have more of those than we do. If one reads the bureau history - we find that a whole bunch of top end radars were lavishly spent on to deal with the tropical cyclone issue after the fallout from Tracey, only for the satellite revolution to make them of very little use.

Interesting on the calibration - I guess I shouldn't be surprised given we just plugged and play with the TITAN and Mesocyclone detection algorithms along with the storm tracking software. I assume that standardised calibration would have been to a highly observed site test? I would have thought there might have been some differences based on the height of radar siting.

When one sees the quality of the Mildura radar - and the tendency to switch it off for wind-finding during convective hours (the 4:45 to 5:30 window for example - even though they have the option not too), you wonder a little - is it really that useful...even a precip rate in excess of a hundred mm an hour wasn't even yellow within the 128km window. Of course one has to wonder if we really make best use of the radar system we have at all in non Metro areas - we have the operational capacity for cell based warnings rather than effective thunderstorm watches over large areas. Anyway, thats a whole different discussion. Once again sorry for the snippyness.

My opinion that Grafton radar is NEEDED to get a doppler. Look at our STW's, they are always so late and not easy to update. It has caused chaos in communities from those dangerous impacts from supercells and potential tornadoes.

My hands up for Grafton get an upgrade. Its poor radar and so underdeveloped compared to US.

Safety comes first than the population.

Late STWs have nothing to do with the radar network in Australia. Thats more a warning system and procedural problem. Which also extends to the types and scope of warnings issued. At the moment Grafton probably services the warning procedure and that would therefore raise the question - should we upgrade this as a priority? Given the lack of knowledge regarding thunderstorm climatology in Australia, and indeed the high end events it is really difficult to use this as a justification to favour one location over another. Unfortunately it is likely that meteorological services in Australia will remain reactionary to the latest killer event (Over the last few years, Bushfires, Tropical Cyclones, Flash Flooding - all have received the funding priority) and this will likely extend to operational observations such as radar.

The long and short of it - don't hold your breath.

Matt no offence intended here mate, But,.. Our radar systems will likely never come close to rivaling that of those in the USA..Theres are highly needed due to the high level of dangerous supercells not to mention high tornado rate.. Add that with the storm related deaths.

If there were a way for the redtape to be unwrapped, Beaurocrapic BS be dropped from what the BOM's initial core role is, then perhaps what we as sideliners have been given little access to would become a lot broader. Oh and a Few pollies take a cracker out of there over inflated payrates and retirement benifits and spread a little more into our weather prediction needs.

And look out side your own and very small chasing region, take for instance all of the areas -not- covered by radar.. IF we were given atleast a radar overlay system as that of the states our weather forecasting probabilities would increase 10fold, add that with that the BOM have to work with and then your worry or Lax STW would become more timely, efficient ohh and accurate.

Grafton have a good radar, very good actually, i use it here when i chase between the lower mnc into the hunter and way out west at times over the Newcastle radar and even at times trust its overlay into the 512 and dont bother with some of the sydney radars,. Thankfully the Namoi went up as it covered a nice blackspot.

There have been many a times when ive chased way out west and even areas not to far from populated regions and there is No radar coverage AT-ALL, I've been onto monster HP supercells some with atleast 10-15km bases pelting golf-baseball hail, 120km winds, possible nader sightings, severe flash flooding,... called these into the BOM with the response oh,.. is it storming out there? At times even these mammoth beasts clearly visible on sattelite.. And these storms have affected countless people over the years to only go un noticed by those that should take the most..and were there any STW not one.

A broader radar network with each and every overlaying and a much better gridded layout of AWS would make one heck of a difference in all acpects..

Even when they decommish the old they should be sent into more remote areas until a time they can be upgraded, some coverage is better then none.

In a nutshell, we are all but squirrels climbing up the wrong tree..
All we can do is do as best we can with whats currently available and just hope and pray the network expands within our lifetime..

A little while back - before Namoi radar was introduced, but after it was announced, i did these litte google earth overlays representing optimal coverage out to about 200km.

Firstly, this has Gunnedah (now Namoi), Cobar, Broken hill and Parkes


secondly, this has the 4 from above plus the current radars.


As you can see, a number of new radars are needed in NSW and of course Australia, but at the end of the day if funding comes through it becomes a game of "who needs it more (i.e affected population numbers)" vs "political agenda". Personally, i doubt much more of Australia will be covered by radar, there are 3 black spot areas i can think of that will maybe one day get one, being the Mallee, Parkes and Mt Isa (who are getting one http://www.bom.gov.au/australia/radar/about/srep.shtml#mount_isa_radar) and of course a whole bunch that should be upgraded or moved to a better location in the same area (longreach for instance) but unless a radar in your backyard is going to sway an election result don't hold your breath for one any time soon.


Simon

I can honestly say I have never heard radars mentioned politically. As for Longreach, that one won't be going anywhere, it's one of the special ones.

from the budget...
LINK


The increased frontline capabilities...
LINK


There will also be $300,000 for a trial of advertising on the BOM site? Trying to drum up revenue....fair enough as long as it isn't popads!!!



Total expenditure(If I am reading it right) for the BOM in 2012-13-

$355,564,000

LINK


Ironically in 2011-12 there was 12.3M spent of trying to have The Wolverine filmed here... LINK

*sighs*

Oh lawdy, I almost messed my pants when I read that on ABC. $300k on a feasibility study for advertising on the BoM website. What a waste of money! How long would it take them to make it back if they decide to go ahead with the plan?

At least they're pumping a bit of money into additional forecasters, will help in getting warnings out on time.

Okay, I have written a long post. I hope I do not show my ignorance here and that my points come across clearly:)(by the way, thanks for the information zathras) -

As the map by Simmah shows, most of the east coast of NSW has pretty good radar coverage. I would say that parts of the Mid-North Coast (particularly around Port Macquarie) and far south-east NSW are the only real weaknesses. I do not consider these are major problems though since storms can certainly be detected in these areas, it's just the finer detail is missing.

I would like to raise a question though. Would the replacement of older radars with newer doppler radars actually result in an improvement in the warnings from the BoM? Take the Grafton radar for example, would the replacement of the existing radar with a doppler radar result in an improvement in the warning capabilities for the Northern Rivers? This may sound like a silly question but bear with me. For the Northern Rivers, the BoM does not issue warnings for specific storms but rather more generic severe thunderstorm warnings. Now I would think that on any given day the meteorologists on duty would assess the potential for severe thunderstorms (ie. potential for damaging winds, large hail and/or tornadoes). Later, if storms are detected by radar and meet a certain criteria then a severe thunderstorm warning is issued accordingly (correct me if I am wrong here-I am thinking spotter reports/AWS obs may also play a role). Throughout the day, the warning area may then be adjusted when needed. Based purely on reflectivity data it usually is possible to identify storms capable of producing large hail. No real need to identify a mesocyclone since supercells are often pretty clear even from PPI scans alone (at the BoM of course they have access to additional information too - lucky them).

In short, I think the BoM generally does are decent job in issuing severe thunderstorm warnings for areas with good radar coverage. There are usually warnings covering storms capable of producing damaging winds and large hail - no major issues with that. Of course there is still the occasional severe storm that goes unwarned though – but I won’t be too critical of that, it happens. One area where I think warnings are inadequate is for tornadoes. This is indeed a very tricky one as in Australia tornadoes are not very common and usually occur in quite marginal conditions. Furthermore, our tornadoes are generally not long-tracked and long-lived supercells producing multiple tornadoes are extremely uncommon. Such short-lived, isolated tornadoes occurring in marginal conditions are just very difficult to warn for. I can think of a couple of events in recent times where tornadoes have gone unwarned, for example, the Evans Head tornado and more recently the Townsville and Asquith tornadoes. The tornado in Asquith is particularly interesting since it occurred close to a doppler radar and rotation was detected, yet no warning was issued! To me this suggests that doppler radars are not going to be a magic solution for warning tornadic storms unless fundamental changes to the warning system occurs. After a tornado has been reported to the BoM, that information is often included within the severe thunderstorm warning. This generally is too late however, as the tornado has already occurred. To warn for tornadic storms, what would be required is to first indicate when conditions are somewhat conducive to tornadoes. If a storm is later detected in a favourable environment and appears to mean business then an updated warning would have to be issued immediately! With this approach, many storms are going to be “tornado warned” but never go on to produce a tornado. This would be a major problem, but then I think warning for tornadoes after they occur is also a problem too.

I am not meaning to be critical here, I think the BoM does a good job. I just wanted to point out that I believe improving radar coverage is not the be all and end all for improving our severe thunderstorm warning capabilities.

Welcome to the gang, Mt Isa.
http://www.bom.gov.au/products/IDR752.loop.shtml#skip
(I notice they've forgotten to draw in the QLD/NT border)

Awesome! This is gonna be great for further tracking cyclones once they move inland. As well as provide better forecasts for that area

Bit extra information for those interested:
http://www.bom.gov.au/weather-services/announcements/radar/mount_isa_radar_nov2012.shtml
http://www.bom.gov.au/australia/radar/info/qld_info.shtml#mount-isa75

Now for one in Central West NSW (on the hills just west of Wellington)and another in central or north west Victoria to replace that horrible Mildura thing.

Homer

Yes, I know Mt. Isa can get cyclones and storms but the Central West of NSW has it's fair share of severe weather, combined with a much greater population. A new radar in the Central West of NSW would ideally cover the area roughly bounded by Coonabarabran-Mudgee-Orange-Young-West Wyalong-Nyngan. Fringe coverage could extend a little beyond this to places like Cobar and Griffith. This would make either Parkes or Wellington a suitable location.