Rainfall Forecasts Should be Benchmarked

ACCORDING to Bill Gates, “You can achieve incredible progress if you set a clear goal and find a measure that will drive progress towards that goal.” This may seem basic, but it’s not practiced enough, and certainly not when it comes to rainfall forecasting.

John Abbot's corvette which was submerged in the Brisbane flooding of January 2011.

John Abbot’s corvette which was submerged in the Brisbane flooding of January 2011.

The Bureau of Meteorology increasingly use their weather and climate forecasts to warn of looming catastrophe. This use of ‘forecasts’ to advance an agenda is common in politics, but it’s not something the Bureau should be engaged in.

A key Bureau goal should be the best possible rainfall forecast for the public. Their rainfall forecast should be presented and reported in a measurable and understandable way. Instead we are given vague probabilities, which research has shown are often misinterpreted by farmers.

Furthermore, there should be some follow-up. For example, at the end of a week, a month, or a season we should be told how reliable their daily, monthly and seasonal forecasts have actually been.

Its five years now since Brisbane flooded, so about five years since I started working with John Abbot and artificial neural networks to see if was possible to actually forecast the extraordinary wet season of summer 2010/2011 in south eastern Queensland.

Back in 2010, sea surface temperature and sea surface pressures profiles across the Pacific suggested we were in for a big wet. Yet the Wivenhoe reservoir upstream of Brisbane, a dam actually built for flood mitigation, was kept full of water.

John Abbot’s little red corvette sports car was drown in the Brisbane flood. It was in a river-side garage in St Lucia, Brisbane, and totally submerged for 36 hours. He was heartbroken. The loss spurred us to see if we couldn’t apply the technique he had used to make the money to buy that car, to rainfall forecasting. In particular, we were keen to see if artificial neural networks with the right algorithms, and high quality historical temperature and rainfall data, could have forecast the flooding. John Abbot regularly used artificial neural networks and historical trading data to successful forecast directional trends in the share market.

By August 2011 we had monthly rainfall forecasts for 20 sites across Queensland, and we wanted for compare our output from the best general circulation model (POAMA) used by the Bureau of Meteorology. But try as we might we couldn’t actually get the taxpayer-funded Bureau to give us the data we needed to make proper comparisons.

The Bureau were not doing the one thing that Bill Gates says is critical to improvement: benchmarking.

After flying to Melbourne, and threatening to jump out a sixth floor window if the data wasn’t handed over (well I exaggerate somewhat), we got access to only enough data to enable us to publish a series of papers. Indeed, the Bureau still refuses to make available the most basic of data which would allow their rainfall forecasts to be objectively scored.

Back in 2011 it was evident that John Abbot and I could do a better monthly rainfall forecast than the Bureau. To our surprise key science managers at the Bureau agreed: conceding that our forecasts were more skillful. But, they argued, climate was on a new trajectory so our method would not work into the future!

This claim is, of course, based on the theory of anthropogenic global warming. This is the same theory that continues to underpin all the forecasts provided by the Bureau through the use of general circulation models.

An alternative approach using artificial neural networks, fits under the umbrella of ‘Big Data’ and ‘machine learning,’ that relies on pattern analysis, and is proving successful at forecasting, where results are properly benchmarked, in fields as diverse as medical diagnostics, financial forecasting and marketing analysis.

I will be in Deniliquin, NSW, on Friday 26th February, showing both temperature and rainfall data for the Murray Darling region that indicate our climate is not on a new trajectory. I will also be explaining the principles of rainfall forecasts using artificial neural networks, and making some forecasts.

I will also show how proxy data giving an indication of climate change over the last 2,000 years can be deconstructed into sine curves. Seven sine curves of different frequency and amplitude potentially corresponding to natural climate cycles driven by variations in the Earth’s orbit and solar activity (e.g. magnetic field) can be used to generate a sinusoidal projection, suggesting future global cooling. Cooling in the Murray Darling Basin is typically associated with period of below average rainfall.

Five sine curves which can be fitted to proxy data corresponding to a temperature reconstruction from a South African stalagmite.

Five sine curves which can be fitted to proxy data corresponding to a temperature reconstruction from a South African stalagmite.

The information session is being held by West Berriquin Irrigators at the local Deniliquin RSL from 6pm. RSVP to Linda Fawns on 0409 044 754 or westberriquinirrigators@gmail.com.

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11 Responses to Rainfall Forecasts Should be Benchmarked

  1. Val Majkus February 23, 2016 at 2:09 pm #

    Go Jen! Any idea when the drought will break in the Murray’s western catchments? Bourke, the Warrego, the Paroo?

  2. DaveR February 23, 2016 at 8:20 pm #

    It became clear some years ago that Australia’s BOM, and with them fellow travelers the UK Met office and NIWA from NZ, were all totally sold on anthropogenic global warming, so much so that the topic was not even up for discussion, let alone scientific examination. The Climategate emails proved that.

    It also became clear that all 3 agencies had incorporated the effects of AGW into their weather forecasting, both short and long term. And what a complete fiasco that has led to in all 3 countries.

    No wonder BOM dont want any review of their forecasting with actual weather or benchmarking with other forecasting methods.

    As Sir Humphrey said: “Its unheard of!”

  3. Daryl McDonald February 23, 2016 at 9:28 pm #

    I have had quite a bit of succes sin the World’s most important profession,..FOOD PRODUCTION, in the past few years by betting on ‘Red’ when the BOM is betting on ‘Black’. Irrigated food production in the MD Basin must be one of the World’s most challenging tasks. Yet through benchmarking and objective analysis, I have been able to achieve good yielDs, and hence sound finacial outcomes.

    Cheers, SLOWLUNR.

  4. Roger February 24, 2016 at 2:25 am #

    A really interesting idea that you have. I would take it in a different direction and use betting / gambling to predict rainfall.. There bureaucracy will hate it but it will probably do a better job at predicting weekly weather.

  5. Debbie February 24, 2016 at 10:26 am #

    Good for you Jen.
    It needs to be said.
    I’m with you Daryl.
    BoM desperately want attention from people like us but we’re all basically laughing at their precipitation forecasts.
    They’re much more interested in proving that their precipitation forecasts are ‘not wrong’ rather than actually working on improving them.
    In a lot of cases they are worse!
    The 2013 precipitation forecasts were woefully incorrect and very much play a part in the disaster that has unfolded in the far west around Menindee Lakes and the Lower Darling.

  6. Robk February 25, 2016 at 5:35 am #

    Well done Jennifer and John. A standout in “innovation and agility”. I wish you all the best. The way you are treated by the establishment is the real test of character of the components of that establishment and I for one, am keen to witness to your progress. Thank you.

  7. spangled drongo February 25, 2016 at 2:22 pm #

    Good stuff, Jen. The drowned Corvette should never have happened and I hope John got compensation. With all the advantages those people had at their fingertips at Wivenhoe they had plenty of time to produce good things if they had been paying attention.

    Even Campbell Newman who was Lord Mayor of Brisbane at that time told them weeks before that it was going to be a big flood but they still went to sleep.

    It just shows you CAN make a sow’s ear out of a silk purse if you really want to.

  8. Michael Cunningham February 25, 2016 at 4:31 pm #

    “Back in 2010, sea surface temperature and sea surface pressures profiles across the Pacific suggested we were in for a big wet. Yet the Wivenhoe reservoir upstream of Brisbane, a dam actually built for flood mitigation, was kept full of water.” True, but the state government was warned as early as October or November of possible severe flood risk; the “responsible” minister never responded to advice he received advocating precautionary measures. Also there were many warnings with advice to reduce the dam level in the week or two before the flood. The failure was at the political level rather than the forecasting level. (FYI, the flood stopped four metres from my back door; I’d expected on the basis of the latest state government advice to have at least 600-800mm inside, and had moved many things to higher ground.) But happy that you are developing better tools for what should be one of the BoM’s major foci.

  9. Daryl McDonald February 26, 2016 at 6:49 am #

    I think the ‘experts’ had been seduced by Tim Fappery and his mates at BOM, CSIRO, & ABC. Now Broken Hill and Sthn NSW irrigators have run out of water,…………………… Laugh then weep.

  10. hunter February 29, 2016 at 11:24 am #

    The miasma of the climate obsessed mind manifests as declining levels of quality science based products and policies. In a way the rationalizations of the climate community to justify their reactionary stance on any issue is similar to that of Imperialists of prior ages. In a sense we are in the age of Climate Imperialism, with a version of “the white man’s burden” as their self serving rationalization.

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