Some projecgtions of future rainfall trends can be found here

I note that in general a drying trend is predicted, but this drying trend is not certain with some model runs predicting an increase in rain. In general the reduction in rainfall seems most severe in winter and spring, and most severe in the south of the continent, with some areas of the north having at least 50% chance of increasing rainfall.

And of course weatherzone has a section for monitoring recent rainfall (link)

A 3 month anomaly chart shows that the south of the continent has been close to or a little above average for Spring, and the north has been below average, which is roughly opposite to the predicted AGW trend. A significant reduction for much of the east due to the El Nino is also obviouis:



The bureau also have a site for monitoring rainfall trends (link)

Overall for South Australia, during Spring there seems to be an upward trend in rainfall, which has been most pronounced for November.



In contrast rainfall for Winter does seem to have a downward trend as predicted by the models, however there is plenty of variation, and the trend is probably not beyond what I think could be caused by natural variability. There is also an obvious multidecadal cycle that we would appear to be close to the bottom of at the moment.

As my signature says zero rainfall in the Townsville area so far this wet season. The outlook is for continued dry spell at least up to Christmas Day by the most recent models.

Hopefully the wet will kick in by the end of December. We aren't desperate for water with at least 3 years supply in the dam but still in all the flora and fauna needs it.

Can anybody tell me why NE NSW is not affected by the El-Nino? I'm pretty sure I've read it somewhere on these forums, and the map Mike posted just proves it once again. It's one thing I've never understood.

You have to remember SBT, that historically most of Townsville's December rainfall comes at the end of the month, co-inciding with the arrival of the monsoon. The MJO is still predicted to arrive right at the end of the month.

There is an archive of all rainfall for sections of Australia here -->> http://www.australianweathernews.com/data/archive/32/ That link is for the Townsville area

Another example is this link which is for the Capricornia and Wide bay Burnett region http://www.australianweathernews.com/data/archive/39/

The trend I found is that

A: It can rain anytime

B: It can be dry anytime..

Yep I know that RD but most of the others around Australia probably don't. All I can say is bring it on and be quick about it Heuy.

And also historically I get more than 17mm in 7 months. This just about matches if not exceeds any dry period I have seen here. Still great totals the last 3 or so years, and especially this year courtesy to Jan and Feb. Can't expect it to continue though.

I posted this in the temperature trends thread and am re-posting it here as it is of relevance:

Warwick Hughes, [ ex BOM ] blog "Errors in IPCC science" has regularly dealt with the way in which the politician's, assisted by some elements in the BOM who have a global warming agenda, have regularly distorted and straight out lied about the declining rainfall in Perth and other Australian cities.
The end result is the expenditure of billions of tax payer's hard earned to build what will in all probability eventually turn out to be very expensive to run and ultimately unneeded and unwanted desalination plants at various locations around Australia.

Hughes blog posting;2009 update- Perth dam catchments rainfall still normal, Govt building $Billion seawater desalination plant #2
Hughes shows that despite some quite hysterical claims by various politicians that Perth's rainfall has been seriously declining over the long term, there is no substantial evidence that any such decline is evident in the data from 1975 to 2009

The posting and the history of the rather corrupted reasons behind the decisions that led to the building of the desalination plant as above can be followed back through the links provided to other similar postings and back up data from Hughes.

Hughes, when he posts which is somewhat irregularly, often provides some very interesting aspects on the Australian climate and climate data and his blog is well worth regularly checking.
He also gets a mention on occassions on some of the most prominent and factual skeptic orientated climate blogs.

That doesn't apply with every elnino Mega. Sometimes the entire east coast misses out.

According to an article I read on Long Paddock some time back the wettest 30 year period in the past 300 years was 1950-1979. The driest was 1770 to 1799. So two things can be drawn from that.

a) Captain Cook and his crew did it tough and

b) the roll out of broadscale agriculture post war coincided with the wettest period in 3 centuries with the belief it was the norm. Any period that fails to meet that level of rainfall is automatically termed a drought when history shows it to be the norm. The reality is that the 50's , 60's and 70's were abnormally wet. The so-called drought is more likely to be exactly what this continent's flora and fauna have evolved from than the wet.

There is evidence long term that supports cycles of wet and dry periods of decades. Usually around 30 years or so. Based on that we may be heading into a wet cycle.

There is another thing to keep in mind. We always measure current rainfall against an "average". For Australia, it is actually a pretty bad measure. (This has been mentioned by someone somewhen in the forums - but I can't find so sorry that I can't attribute).



If it indeed is the case that the rainfall "norm" for Australia is drought irregularly interrupted by floods (as to me at least seems to be the case), then rather than a mean or average, the median may be a better measure. If we hypothetically consider the following rainfall pattern:

Y0 – 480mm
Y1 – 520mm
Y2 – 510mm
Y3 – 500mm
Y4 – 490mm
Y5 – 1000mm
Y6 – 500mm
Y7 – 510mm
Y8 – 420mm
Y9 – 520mm

If we consider the average for the above then, bar the “BIG” one (Y5), every year is below average (550mm in this case). On the other hand, the median here is 515mm (510mm+520mm)/2. In this case that would be a far better measure of the rainfall “norm” than the average - half the years are above and half below this number. And infact, (including the extreme “drought” year Y8) all are well within one standard deviation (154mm) – another measure of significance.

And as CF hints at above, if the average is further based on a particularly wet period, then average rainfall will be few and far between in “normal” periods…

Where there are irregular and sizeable extremes – the average is pretty much well meaningless.

Yes indeedy, the median would be a better measurement, and should result in somewhat less "we didn't reach the average AGAIN this year/month/etc" rages on this forum and when you're chatting to any other person in the street who is interested in the weather.

I just spotted Mega's post too, and yes there are times where NE NSW is affected...i remember periods of the 90's where we (Coffs) copped some pretty long periods of poor rain (for there) and lots of water restrictions. Though that was partly due to the fact that the dam had a tiny capacity, which was fixed around 2000'ish.

Yes. 1993 & 1994 were very dry years for Kempsey in NE NSW too. Yearly rainfall totals of 659mm and 601mm, respectively. Kempsey's average is 1207.5mm, so 1994 failed to meet half of the yearly average. Such low rainfall had not been seen since the Federation drought. I remember a big downpour of rain on Christmas Day 1994 that really was the sign of that drought breaking with 1995 immediately bringing better rainfall.

Every year here in the Alice that receives less than 100mm has been followed by over 300mm the next with January being the wetest.
So if the trend continues 2010 will be a good year and January should receive over 100mm fingers crossed!!

This graph shows the cycles that occurred in the annual rainfall for Alice Springs (PO) up to 1987 (it closed then), and the projection of likely cycles up to 2015 (I've not added in the data that started in another part of the Alice from around 1983 but I doubt there would be any real difference in the cycles there):



This is on the basis of there being 3 cycles in its annual rainfalls, every 2.5,8 and 28 years. Notice that the curve rises from 2009 through 2010 and again towards 2013. This would seem to bear out forecasts of more general wetter times ahead over the next decade or so.

Keith you are a great source of info!

Here's the rainfall graphic from the latest climate summary from BoM:



Hmmm... Looks like Australia has had the second highest decadal rainfall in the last 100 years! The big dry? (tongue firmly in cheek)

Just goes to show how "averages" can mislead...

FOUND THIS VERY INTERESTING RAIN AND WEATHER GEAR ON ANOTHER SITE THREAD
FROM http://www.boards.ie/vbulletin/showthread.php?p=63869733 posted by OLD AUSSIE

"The records below indicate that the worst extremes of climate change were there previously and that Australia's extremes in weather conditions have moderated.

.......

The Brisbane Courier Friday 11 October 1889

THE PREDICTED DROUGHT. Australian weather statistics 1782 - 1889.
" In order to throw some additional light on the above question, I will furnish a few condensed Australian weather statistics of the last 107 years, and if anyone can found a positive forecast on them he is welcome to do so ; all that I can see in them is the simple fact that floods and droughts alternate out here with "lucid intervals" of ordinary settled and moderately wet or dry weather.
Captain Cook in 1770 says little about the weather. Dampier in 1690 or thereabouts was equally silent.
Captain Matthew Flinders reports drought and bush fires from 1782 to 1792.
There was a great drought in 1797 for 100 miles round where Melbourne now stands ; 1799 to 1806 were very wet years, and in 1806 the floods culminated by a rise of 101 ft. at Windsor, on the Hawkesbury River.
The crops were destroyed, wheat rose to 80s. a bushel, and a famine prevailed.

The excessive rain kept on till 1810, but 1811 cut it short, and was so dry that water was worth 8d. per bucketful in Sydney.
This drought was sharp but short, and there was plenty of increasing rain for years afterwards, till in 1820 the Hunter River rose 37ft.

Ten years now elapsed without any more floods, and it was so dry from 1826 to 1829 that water at last became worth 4d. a gallon in Sydney. 1830 saw the first flood for ten years.

Ordinary weather followed till 1837, but 1838 and 1839 saw the champion drought of the century. Stock were all but exterminated. The Murrumbidgee is a great river, 150ft. wide, 60ft. deep, and overflows its banks, like the Nile, when the head snows melt, for five miles on each side to a depth of 3ft. This gives a volume of water equal to a river of 1450 ft. wide and 120 ft. deep, and besides this it fills a group of lakes each from seven to eighteen miles in diameter.
Yet this great river dried up so thoroughly in 1839 that the fish died and putrefied at the bottom of it.

I make no comments on what such a drought now would do to Queensland, and I am at present only going for dry facts and bald statistics.
1841 broke up this drought with the champion flood of Queensland; the Bremer River rose 70ft., and the Brisbane bar not being then dredged, there was no quick "get away" for the water, and it filled the lower story of the commissariat stores here, and Ipswich was very short of rations for some days.

Moderate rain carried the colony of Now South Wales (then the only one) on till 1849, when dry weather began and lasted till May, 1851.

The scattered bush fires of Victoria got " boxed" into one mighty whole on 6th February, 1851 (" Black Thursday "), before a southerly hurricane which sent smoke and leaves across Bass Straits.

1852 brought a flood that swept Gundagai away and drowned the inhabitants ; 1853 saw great overflows of the Lachlan, Murrumbidgee, and Darling rivers, but not from local rain ; 1854 was dry; 1855 and 1856, ordinary weather; 1857 was a flood year, with three months ceaseless rain from February to May.
Settled weather lasted till 1863, which, with 1864, both gave heavy flood. The weather settled again till 1873 (bar a small drought up North in 1866), which, with 1875, was very wet, and gave a flood each.

Settled weather again carne, with a small local flood in 1879-80 ; 1882 very wet: 1883 to 1886 very dry; 1887 very wet; 1888 very dry; 1889 moderately wet.

Here we have 107 years of statistics, and who can discern from them the rule that guides the weather ? A matter which enters so largely into our health and comfort, happiness and prosperity, that I hope to be excused for thus dwelling upon it. ......
N. Bartley The Brisbane Courier 1889 "
Source: The Brisbane Courier Friday 11 October 1889



Reports of Drought by our Ealy Settlers.

Governor Arthur Phillip 1791
Governor Arthur Phillip wrote the following to the Colonial Secretary, the Right Honourable W. W. Grenville on 4 March 1791:

"From June until the present time so little rain has fallen that most of the runs of water in the different parts of the harbour have been dried up for several months, and the run which supplies this settlement is greatly reduced, but still sufficient for all culinary purposes... I do not think it probable that so dry a season often occurs. Our crops of corn have suffered greatly from the dry weather."

On 5 November 1791, the governor of this colony, Arthur Phillip, reported that the normally perennial 'Tank Stream' river flowing into Sydney Harbour had been dry for "some months".
It did not flow again until 1794. Phillip marks the start of the droughts in July 1790; no rain had fallen by August 1791 **

During the drought in 1814 Governor Macquarie had to import food to avoid what he called:
"the heavy calamity of very great scarcity, both of animal feed and of grain, if not in an actual famine."

Well the trend has continued with the Alice Airport having over 130mm so far this January 2010.