Category Archives: BoM Australia

Weather Bureau for Australia

BoM summer Outlook axed in a fortnight now “lives at risk” due Vic floods

Summer rain Outlook 16 Nov foretold near average for SE Aust. Summer rain Outlook 30 Nov better but already wrong if the ‘Lives at risk’ scare is half correct. OK so anybody can make mistakes – lets check what they forecast for November rain on Oct 12th and then on Oct 26th. Here is map of November rain percentages so the later Outlook on 26th Oct was worse than the one on the 12th. Taxpayers could save $millions slashing BoM budget – we could get forecasting from www. Let BoM do core job of running our weather observations network properly.

Cape Bruny AWS reads warmer than Stevenson screen 18m away

There are two temperature series for Cape Bruny on the southern tip of Tasmania. CAPE BRUNY LIGHTHOUSE 94010 and it seems that an AWS was commenced in 2002 CAPE BRUNY 94198. The BoM site map shows the screen and AWS are ~18m apart.

I downloaded the max and min monthly data from CDO online and for the years of overlap 2002 to 2016 the CAPE BRUNY 94198 annual max is 0.45° warmer on average than CAPE BRUNY LIGHTHOUSE 94010. Furthermore the AWS was warmer than Lighthouse in every year.
For the same period the CAPE BRUNY 94198 annual min is 0.16° cooler on average than CAPE BRUNY LIGHTHOUSE 94010. Furthermore the AWS was cooler than Lighthouse in 15 of the 19 years, the readings were the same for 2008 and 2012, 2013, 2014. An interesting case of BoM AWS reading on an annual mean temperature basis (how global warming is measured), consistently 0.29° C higher than Stevenson screen readings only 18 metres away. Yet the BoM maintain their AWS are calibrated to be equivalent to liquid in glass thermometers.

BoM says Hobart October 2017 was the warmest ever

But the BoM fails to say that outside the Hobart urban heat island (UHI) record warmth is harder to find.
I checked the following stations around the Hobart region – first the mean monthly max – only Tasman Island agreed with Hobart but the site has only operated from 2002.

then the mean monthly min gives a similar result.

So the BoM should have told the ABC that although central Hobart had a record warm October – few other sites in the district confirmed that so on balance you would assume that the UHI effect has been quietly ramping up warmth in Hobart data for a ~century.

Australian BoM October rain Outlook disaster

Could have done better – miniscule areas with above average rain predicted but it looks as if about half of the misgoverned nation enjoyed over average rain. And they get Tasmania exactly wrong.
October max(daytime) temperatures were forecast to be high in most of the coastal rim and cool in the centre extending to the SW. Reality was that pattern was nothing like that with a fail along the coastal half of Qld and many central failed areas. I wonder who benefits from these Outlooks – anybody out there hangs out for them?
October min(night) temperatures were forecast to be a bit cooler than the days with a similar shape. Reality was the peak hot nights were nowhere near where they were predicted but there were some small wins in the cool areas. Again I wonder who benefits from these Outlooks.

Lets check the BoM 3 Month Outlooks – first rain – OK I think it shows not one square centimetre of Australia was due for above average rain. But reality was that vast areas of Australia had above average rain. Monster fail.
Now Max (daytime) temperature – I think it shows not one square centimetre of Australia was due for average or below average temperatures. But reality was that large areas of Australia from Carnarvon-Southern Vic- Tasmania and FNQ coast experienced near average or very mildly warm temperatures . And nowhere in the rest of Australia did the scale of temperature anomalies reach the extreme level of the predictions. Fail.

Now Min (night) temperatures. Not one square centimetre of Australia was due for average or below average night temperatures. Yet in the real world large areas were either anomalously cool or only very mildy warm. Big fail here.

Heat-wise – September was a pussy in Australia

Charts here of max t anomaly show you several previous Septembers were hotter than 2017 – starting with 1928.
The UAH satellites Australia band has eleven hotter Septembers.

You can make BoM max min and mean t anomaly maps – have fun.
Going back to the charts if you make a mean t anomaly chart for Australia – which gives you a relative idea of what goes through to IPCC globull-warming central – the Oz contribution heat wise last month was even more insignificant with many previous Septembers warmer than 2017. There – some perspective.

Listing worst BoM errors in Goulburn Airport or Taralga daily minimums

Data from CDO disk bought from BoM in 2007 plus from CDO online then compared to Minimum temperature daily contour maps. Ask me if you can not find daily t in CDO or the maps.

Error A 5 Jan 1991 Goulburn Airport min = 9.7 – Taralga min = 19.2 – diff = -9.5 There is no sign of the 9-12 contour colour near Goulburn so the BoM map is indicating Goulburn is in error. Proved by Goulburn Tafe @ 20.5.
www.bom.gov.au/jsp/awap/temp/archive.jsp?colour=colour&map=minave&year=1991&month=1&day=5&period=daily&area=ns
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