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.
Let’s be fair.
It is very hard to predict October rainfall on 29 September.
I recommend that BoM should predict October rainfall on 29 October.
They could do this as an adjunct to temperature homogenisation.
In our area (SE Qld) we got more than 3.5 times the average but not quite the record set in 1972 of about 4.6 times average. BOM should be looking at the SOI. If predicting a week ahead they should look at what ants do. We knew it was going to rain before BOM.
Slightly OT.
Again the Bureau shows max anomalies above average where the actual temps show below average.
NSW districts 56, 57 and 58 are shaded in above average for Oct, 2017 (but the actual temps are below).
www.bom.gov.au/web03/ncc/www/awap/temperature/maxanom/month/colour/history/ns/2017100120171031.gif
www.bom.gov.au/climate/current/month/nsw/summary.shtml
This use of the 1961-1990 averages as a base anomaly appears to help the BoM’s cause.
Good point Ian.
I checked here www.bom.gov.au/jsp/ncc/climate_averages/temperature/index.jsp#what and it’s true that the BoM is still on 1961-90 anomalies. Since according to their dodgy data we have piled on close to one degree of warming since then (see www.bom.gov.au/climate/updates/articles/a015.shtml), what on earth is the point of assigning probabilities of exceeding those levels over a season? Practically everywhere will be “likely” to exceed the 1961-90 average over 3 months or longer, which is in fact what the BoM always predict!
Standard practice is to use as normals the average for the LAST 30 years, updated at least every ten years. That means we should already be on 1980-2010. Predictions against those averages would be far more meaningful. But of course since the BoM’s temperature predictions themselves are so bad anyway, it hardly matters what they compare them with.
Doctored trends, superseded normals, and totally unreliable predictions – what a trifecta for the $300-million a year weather bureau of a supposedly advanced nation!