IPA Today

Fear, Flooding, Forecasting & Australia’s 2022 Official Rainfall Statistics

Written by
8 January 2023
Originally appeared in Dr Jennifer Marohasy's Website

This year the Australian Bureau of Meteorology waited until after close of business on Friday 6th January 2023 to release the official climate statistics for 2022. After claims of unprecedented extreme rainfall all year, the statistics must be disappointing for those animated by the idea of a climate catastrophe:

Nationally averaged rainfall was [just] 25% above the 1961–1990 average at 582.2 mm, which makes 2022 [only] the ninth wettest on record for Australia.

It is the sixth wettest year for Eastern Australia, where there had been extensive flooding.

Flooding that the Climate Council relentlessly blamed through 2022 on climate change. The Council is headed by Tim Flannery who at the end of April 2007, when most of Australia remained in the grip of severe drought, hyped global warming by claiming our dams would never fill again. Last year they filled to overflowing – again.

Eastern Australia, situated to the immediate west of the southern Pacific Ocean, has always experienced cycles of drought or flood depending on the El Nino-Southern Oscillation which modulates global temperature and rainfall.

Farmers like my father always linked this cycle to changes in the declination of the Moon and there are now research papers explaining the phenomenon. For example, Jialin Lin & Taotao Qian’s ‘Switch Between El Nino and La Nina is Caused by Subsurface Ocean Waves Likely Driven by Lunar Tidal Forcing’ published in 2019 by Nature.

Wet years are usually cooler years in Australia though the BoM claims last year to have been 0.5 °C warmer than the 1961–1990 average. In fact, discounting for the new electronic probes platinum-resistance probes* that I have shown can record 0.4 °C warmer for the same weather and the industrial scale remodelling (the technical term is homogenisation) that strips away past cycles of warming and cooling to the extent that past temperatures are artificially cooled relative to the present, sometimes by almost 3.0 °C (yes that much!) – in reality, last year is likely to have been on average much cooler.

But what about the rainfall statistics? Are all 697 rainfall stations spread across the land mass of Australia actually used to calculate Australia’s average rainfall, and how reliable are the new electronic rainfall gauges?

According to the BoM’s newly released 2022 statistics, the wettest year on record for Eastern Australia is still officially 1950 with 1021 mm, followed by 2010 (1012 mm), then 1956 (986 mm). The 1970s were also wet, especially 1974 with 960 mm, and 1973 with 853 mm.

The official rainfall total for Eastern Australia, where there was so much flooding through 2022, is 819 mms – much less than I expected.

There had been images on television of families huddled on the roofs of homes in Lismore on the morning of 28th February 2022. Waters rose, first entering backdoors, then filling living rooms, then forcing families to hitch each other onto rooftops. Surely the rainfall in places like Lismore was unprecedented?

Many of the submissions to the NSW Flood Inquiry from the Lismore community blamed the new highway built across the floodplain, not the rain, for all the flooding. They explain that the highway acted as a dam stopping water from flowing away and downstream.

Official reports blamed global warming, and either incorrectly reported the 24-hour rainfall total for Lismore (they published 146 mm which is the total for the 24-hours to 24th February, not 28th February 2022) or the reports ignore this important statistic altogether because the official rainfall gauge in Lismore failed. Yes, failed on 28th February 2022. And the Bureau has failed to acknowledge anywhere that there were no measurements from this official rainfall gauge in Lismore from 27th February through until 22nd July 2022.

The Bureau has also failed to acknowledge that there is data available from an alternative rainfall gauge in Dawson Street Lismore that recorded 467 mm to 9am on 28th February. This record only exists as a screenshot taken by a concerned citizen reposted at my blog on 23rd August 2022.

What should be acknowledged as a new 24-hour rainfall record for Lismore of 467 mm on 28th February has not been entered into any of the official reports or into the official Australian Data Archive for Meteorology. It presumably is not therefore part of the data used to decide that 2022 was (only) the ninth wettest on record for Australia.

There was a Special Climate Statement 76 – Extreme rainfall and flooding in south-eastern Queensland and eastern New South Wales published by the BoM on 25th May 2022 replete with regional distribution maps of rainfall across broad geographic bands and with intervals of varying quantity, with the highest value of 200 mm to an unknown total amount (pg. 5). It claims that there has been an increasing trend in extreme hourly rainfall (pg.18) but no actual data is provided – the reference is to State of the Climate 2020. I’ve also been through that report. It provides no actual observational data, nor does it cite any peer-reviewed study.

There is no mention of the reliability of any of the data – temperature or rainfall – by the Climate Council. It can only be concluded that they care more about the narrative. A narrative that is intentionally about blame and frightening especially women and children into action. It might give purpose to the lives of activists like Tim Flannery but at an enormous cost to our children, many of whom are now chronically anxious about the weather.

I was woken on Friday morning at 4am to the sound of rain. Not soft, steady rain. More like a herd of buffalo pounding across my tin roof – intense rain here in Yeppoon, to the east of Rockhampton and to the west of the South Pacific, a vast body of water that reaches about halfway around the Earth. As a child who grew up in the tropics on a farm to the south of Darwin in the Northern Territory of Australia, I used to be reassured by the drumbeating of that intense rain. It signified the beginning of the monsoon and the end of the bushfire season. Now children are being taught to fear something as natural as heavy rain in northern and eastern Australia. The messaging on television has been relentless: rainfall is more intense now – we have a climate emergency. Fear of rainfall is increasing in Australia that is one of the driest continents on Earth.

Climate activist Mali Poppy Cooper, 22, made national headlines when she locked herself to the steering wheel of her car on the approach to a Sydney Harbour tunnel to protest all the flooding in Lismore. Terrible flooding. She was bailed on condition she get psychiatric help. There are stories emerging now of children who experience panic attacks every time it rains.

All through 2022 there was reporting and storytelling, now incorporated into the school curriculum, about how the intensity of the rainfall has increased at Lismore and other locations. Never mind that the new automatic rainfall gauge at Lismore failed and that other gauges in the flood zone show no increase in rainfall intensity or volume when considering the historical record back to at least 1900.

Back in May 2022, Chris Gillham and I made a submission to the NSW Flood Inquiry showing that for the 20 longest rainfall records for locations in the 2022 flood zone there has been no overall increase in the intensity or frequency of extremely wet days to 2021. The wettest year, measured as the year with the highest number of 99th percentile rainfall days by volume since 1900, is still 1974.

We have updated this report** to include the daily rainfall values to the end of 2022 and an additional 5 locations. Our analysis combines data from days with extreme rainfall and compares values since 1900 and for 25 locations both within the flood zones and south to the Sydney region which did indeed record its highest annual total rainfall during 2022. There is still no general trend of increasing rainfall intensity, and therefore it is nonsense to blame climate change for the 2022 flooding. The year 1974 remains the year of most intense rainfall, which was also a year of above average cyclone activity including the infamous Cyclone Tracy.

It is not only a fact that the volume and intensity of rainfall is not increasing, but neither are the number or intensity of cyclones crossing the Australian coastline. They have in fact been in decline since at least 1979, the first year from which we have reliable satellite data.

It was very wet in southeast Queensland through 2022. I was in Brisbane on 3rd March 2022 helping with the clean-up after the devastating flooding of that city.

The Brisbane city flood gauge reached 3.85 metres on the morning of 28th February 2022. This exceeds the major flood level mark but falls short of the 1974 and 2011 floods which reached 5.45 metres and 4.46m, respectively. The Brisbane city flood gauge record goes back to 1832, with the highest flood being recorded in 1841. There was also flooding in 1873 and 1893. According to Aboriginal legend the Brisbane floodplain was not a place for building humpies, yet the European settlers who followed have built a whole city.

The flooding of Brisbane in 1974 was predictable in that the SOI index was an incredibly high 31.6 in November 1973, showing an extraordinary pressure gradient across the South Pacific as measured between Tahiti and Darwin. I was fearful of flooding in late 2010 as the SOI was again very high, 27.1 in December 2010.

After the floods of 1974 the Wivenhoe dam was constructed to ensure Brisbane never flooded again.

Despite the very high SOI and warnings from the mayors of some regional councils and farmers interested in long range weather forecasting and lunar cycles, the Wivenhoe reservoir upstream of Brisbane – built for flood mitigation – was kept full of water because it was believed by the authorities that the ‘dams would never fill again’ because of climate change. They had heard Tim Flannery. The dam operators kept Wivenhoe brimming with water as we entered the 2010-2011 summer despite the high SOI values.

When the torrential rain began to fall, as it always does, and because Wivenhoe was so full of water already, the flooding of January 2011 has officially been documented as a ‘dam release flood’ caused by the emergency release of water. This from a dam originally built for flood mitigation following devastating flooding in 1974. If water levels in Wivenhoe had been reduced through 2010, there would have been no climate emergency.

A class action brought against the Queensland government and one of the dam operators found they were negligent in the way the dam was managed and awarded compensation to those that had suffered loss as a result. But no money has yet been awarded, in part because of subsequent appeals.

During the worst of the flooding last year, in 2022, the dam operators again kept releasing water causing the city of Brisbane to flood. However, this time the torrential rain had stopped. Water kept being released because the BoM incorrectly forecast that more – even worse – rain was imminent. Rain that never eventuated. Now the mantra is that it just keeps raining and the dams will inevitably overflow.

I have benchmarked the skill of the BoM’s simulation modelling for seasonal rainfall forecasting in a series of papers with John Abbot. Our research papers, published in international peer-reviewed journals, as conference papers and book chapters from 2012 to 2017, show that the rainfall forecasting methods developed over a period of 20 years by the BoM provide no significant improvement in forecast skill beyond just simply calculating a long-term average rainfall for the period in question. This is despite spending hundreds of millions of dollars on expensive computers and models that attempt to replicate atmospheric processes.

There are much better methods for seasonal rainfall forecasting that use statistical modelling coupled with the latest advances in machine learning. This is a method that John Abbot and I pioneered and that is detailed in those same scientific papers. The first of these papers was rejected by the BoM’s own publication series in 2012, but accepted and published by the Chinese Academy of Science (Advances in Atmospheric Sciences, Volume 29, Number 4, entitled ‘Application of Artificial Neural Networks to Rainfall Forecasting in Queensland, Australia’).

While the SOI was very high during December 2010, and thus the extreme rainfall of January 2011 easily forecast, the SOI was only 13.8 during December 2021. It was thus not at all obvious to those interested in pressure patterns across the Pacific Ocean as an indicator of seasonal rainfall that we should expect flooding.

The flooding through 2022 was likely exacerbated by an atmosphere exceptionally high in volcanic aerosols from the explosion of the Hunga Tonga-Hunga Ha’apai volcano a month earlier. If the BoM had been tracking volcanic ash from that volcano and using a more reliable system of rainfall forecasting, and there was better town planning with the new highway through Lismore built on piers to let the water flow under the road and across the floodplain, there may have never been the tragedy at Lismore.

Exceptionally high rainfall totals in Hong Kong in 1982 correlate with the arrival of stratospheric aerosol plumes from the eruption of El Chichon in Mexico. Atmospheres high in aerosols can contribute to exceptionally high rainfall, but this is ignored by mainstream climate scientists including meteorologists at the BoM who continue to run simulation models inventing a role for carbon dioxide.

El Chinon was a large volcanic eruption, reaching 31 kms (19 miles) into the atmosphere. Mt Pinatubo that erupted in the Philippines in 1991 was larger, reaching 40 kms (25 miles) and causing surface cooling in the Northern Hemisphere of up to 0.6°C. The eruption of Hunga Tonga in the South Pacific on 15th January 2022 was even larger, reaching 57 kms (35 miles). Yet the BoM continues to deny it has had any effect on temperatures in the Southern Hemisphere. And the Climate Council would be hard pressed to blame us for explosive volcanic activity.

The aerosol plume from Hunga-Tonga travelled west, reaching Australia on 18th January 2022. Flooding followed with main railway lines and roads in central Australia washed away. By February 15th, the volcanic ash had circled the Earth and was back over Australia, evidenced by unusually intense sunsets. After that, it began to rain so intensely that Brisbane flooded – again, and so I was part of the clean-up on 3rd March 2022.

That afternoon a group of us working in Sandford Street, St Lucia, were told to down tools at 2pm. The BoM was announcing on radio that our situation was ‘dangerous’ and ‘potentially life threatening’. All the while the sun kept shining. Not a drop of rain fell from the sky and the waters of the Brisbane River below continued to recede.

As I drove out of Brisbane a few hours later, the flash flooding forecast for that same afternoon was cancelled. Next, on radio there was talk of the climate emergency and the scary ‘rain bombs’ of five days earlier. How it was all ‘unprecedented’ – the volume and intensity of rainfall. More than one metre of rain had fallen at some locations in just a few days.

The rain that fell in Brisbane was not unprecedented, neither in volume or intensity. Back in February 1893 nearly two metres of rain had fallen over a similar period of time at Crohamhurst just to the north of Brisbane. And there was no mention of the 24-hour record of 907mm, the amount of rain that fell at Crohamhurst on 3rd February 1893. This remains the highest 24-hour rainfall total for anywhere in Australia and it was 130 years ago. That rainfall recording station has since been closed.

There was also no mention on the radio of the Hunga Tonga-Hunga Ha’apai volcano a month earlier, the largest volcanic eruption anywhere on Earth so far this century, and how these volcanoes can supercharge the atmosphere to make Eastern Australia even more susceptible to heavy rainfall – and that the ash plumes could be monitored as they cross the Pacific Ocean just as weather stations monitor air pressure and so provide an SOI index.

There was also no mention on the radio that evening of 3rd March 2022 that the BoM seasonal rainfall forecasts are completely lacking in any skill. That the BoM consistently gets its seasonal rainfall forecasting wrong, and that not only did it not forecast the torrential rains at Lismore on 28th February 2022 but that it has so far refused to record any value for the 24 hours to 28th February 2022 at Lismore into the Australian Data Archive for Meteorology.

The most accurate seasonal weather prediction systems rely on statistical models using advances in machine learning to elucidate patterns in historical data. So, the integrity of Australia’s temperature and rainfall record is paramount. Yet both temperature and rainfall records are being constantly eroded by the BoM. Major rainfall events are not being entered into the database. Important weather stations are being closed and the available temperature data remodelled, stripping away evidence of past cycles of warming and cooling that correspond with periods of drought and floods.

But of even more concern to me is that since 2011 the BoM has stopped numerical averaging of the instantaneous one-second readings from the temperature probes electronic probes in its automatic weather stations used to measure temperature. I have shown that this could result in a probe recording up to 0.4 °C warmer for the same weather. To know the effect of this more generally on Australia’s climate through 2022 the parallel data – the measurements taken from mercury thermometers and electronic temperature probes in the same weather stations – needs to be made public. Since 2015, when I first requested this data, the Bureau has steadfastly refused to release it but my appeal against this will finally be heard on 3rd February 2023 by the Administrative Appeals Tribunal in Brisbane.

A helicopter came to rescue the residents atop the hotel in Lismore (Nine)
A helicopter came to rescue the residents atop the hotel in Lismore (Nine)


* Monday 9th January: Electronic’s specialist Lance Pidgeon has reprimand me for incorrect use of the terms ‘electronic probe’ and ‘electronic thermometer’. The new temperature measuring devices used by the BoM are platinum-resistance probes or platinum-resistance thermometers, specifically they use a PT100 platinum resistor, which is a simple electrical resistor.

And as Lance has further explained, and I quote:

The 2018 version of the WMO standard has been written to remove the BoM excuse for not averaging. Someone there is on the ball. Although I do need to check what the status of this is right now, the wiggle room they found in the 2014 WMO standard had been removed from the 2018 standard last time I checked.

The BoM go against the standards in four ways. All of them important. One of the main reasons the WMO gives for the [numerical] averaging is electrical interference. The BoM as you know claim to have put a sleeve on the platinum resistance thermometer to slow its thermal response time down to match the thermal response time of a mercury thermometer, about 30 seconds at 5 M/S wind speed. This does nothing about electrical noise. Nothing at all. It is electrical noise that could randomly synchronize with any one of the the 60 spot readings to shift the temperature up by 0.3 for a single reading and if it happens to increase at a rate of 0.3 per second and continue to syncronise for the right 60 samples then an 18 degree increase is theoretically possible…

More on the other ways BoM go against the WMO standard in a future blog post.

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Jennifer Marohasy

Jennifer Marohasy is a Senior Fellow at the Institute of Public Affairs

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