Eight days out from the 21 May 2022 federal general election and much of the NSW Northern Rivers region is on flood watch again

Australian Bureau of Meteorology (BOM):

Flood Watch for the Northern Rivers and Central West

Issued at 12:21 pm EST on Thursday 12 May 2022

Flood Watch Number: 3

MINOR FLOODING POSSIBLE IN THE NORTHERN RIVERS AND CENTRAL WEST FROM THURSDAY

A trough over western inland New South Wales will generate further moderate to heavy rain in many areas of the Central West on Thursday. This may cause minor flooding along the Castlereagh, Macquarie and Bell Rivers from Thursday night.

* Reissue to include Castlereagh *

River level rises have been observed from recent moderate rainfall in the Northern Rivers. Further moderate showers expected on Thursday may see river levels rise to minor flood levels.

Renewed minor flooding is also possible along the Bogan River where a flood warning is current.

The Bureau is continuing to monitor the situation and will issue further catchment specific warnings if and when required.

Catchment soil moisture is average.

The weather system is expected to cause flooding for the catchments listed. Flood Classes (minor, moderate, major) are only defined for catchments where the Bureau provides a flood warning service.

Catchments likely to be affected include:

Tweed and Rouse Rivers - minor flooding 

Brunswick River and Marshalls Creek - minor flooding

Wilsons River - minor flooding

Richmond River - minor flooding

Castlereagh River - minor flooding

Orange, Molong and Bell River - minor flooding

Turon and Macquarie Rivers to Burrendong Dam - minor flooding

Macquarie River d/s Burrendong Dam - minor flooding

Flood warnings are current for the Culgoa, Bokhara, Bogan, Paroo and Warrego Rivers.

For the latest flood and weather warnings see www.bom.gov.au/nsw/warnings/

For the latest rainfall and weather forecasts see www.bom.gov.au/australia/meteye/

For the latest rainfall and river level information see www.bom.gov.au/nsw/flood

 [my yellow highlighting]

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There is a chance of above median rainfall across much of the continent from 14 May 2022 to September 2022.

According to BOM long range forecasting there is also a 50-60% chance of the Page and Richmond electorates in the Northern Rivers region being “unusually wet” between 14 to 27 May 2022.

Stream Flow Forecast

Click on image to enlarge

Climate outlook overview

Issued: 5 May 2022

Winter (June to August) rainfall is likely to be above median for most of Australia, except south-western Australia, the south-east coast, and southern Tasmania which have roughly equal chances of being above or below median.

June to August maximum temperatures are likely to be above median for northern, south-western, and south-eastern parts of Australia, but below median for broad areas of inland southern and central Australia.

Minimum temperatures for June to August are very likely to be warmer than median across almost all of Australia.

The weakening La Niña, the chance of a negative Indian Ocean Dipole, and other localised drivers are likely to be influencing this outlook.

Latest Climate Driver Update, 10 May 2022:

La Niña maintains strength

The 2021–22 La Niña event continues in the tropical Pacific, with little change in strength in the past few weeks.

Several indicators of La Niña, including tropical Pacific sea surface temperatures, cloudiness near the Date Line, and the Southern Oscillation Index (SOI), have maintained or slightly increased their strength over the past fortnight. However, beneath the surface of the tropical Pacific, waters have warmed closer to neutral El Niño–Southern Oscillation (ENSO) levels.

Most climate models surveyed by the Bureau indicate a return to neutral ENSO by the early southern hemisphere winter. Only one of seven models continues La Niña conditions through the southern winter. La Niña conditions increase the chances of above average rainfall for much of eastern Australia, while neutral ENSO has little influence on rainfall patterns.

The Indian Ocean Dipole (IOD) is neutral. All climate model outlooks surveyed suggest a negative IOD may develop in the coming months. While model outlooks have low accuracy at this time of year and hence some caution should be taken with IOD outlooks beyond May, there is strong forecast consistency across international models. A negative IOD increases the chances of above average winter–spring rainfall for much of Australia. It also increases the chances of warmer days and nights for northern Australia.

The Southern Annular Mode (SAM) index is currently positive and is forecast to remain positive for the coming four weeks. During autumn SAM typically has a weaker influence on Australian rainfall, but as we approach winter, positive SAM often has a drying influence for parts of south-west and south-east Australia.

The Madden–Julian Oscillation (MJO) has recently strengthened in the western Indian Ocean. Most climate models indicate the MJO will briefly weaken, and then re-strengthen again later this week in the Maritime Continent or western Pacific region. Should the MJO re-strength in the Maritime Continent region, it can enhance rainfall in north-eastern Australia. It also typically increases cloudiness to Australia's north.

Climate change continues to influence Australian and global climate. Australia's climate has warmed by around 1.47 °C for the 1910–2020 period. Southern Australia has seen a reduction of 10–20% in cool season (April–October) rainfall in recent decades. There has also been a trend towards a greater proportion of rainfall from high intensity short duration rainfall events, especially across northern Australia. [my yellow highlighting]

Latest Bureau Of Meteorology Climate Driver Update, Australian Daily Extreme Temperatures Jan-Aug 2021 & Spring rainfall predictions

Issued 31 August 2021

Tropical Pacific Ocean likely to cool, but remain ENSO-neutral

The El Niño–Southern Oscillation (ENSO) is currently neutral. Sea surface temperatures (SSTs) in the central tropical Pacific Ocean are near average, despite slowly cooling over the past two months. Waters beneath the surface are slightly cooler than average.

While most models indicate SSTs in the central tropical Pacific are likely to continue cooling over the coming months, ENSO-neutral is favoured to persist. Only two of the seven models surveyed suggest SSTs will remain cool for long enough to be considered a La Niña event. This cooling of the tropical Pacific may be contributing to the wetter than median climate outlooks in Australia.

Most climate models predict the negative Indian Ocean Dipole (IOD) event will persist through the southern hemisphere spring, despite current values rising marginally above the −0.4 °C threshold. Stronger-than-usual easterly winds across the tropical eastern Indian Ocean over the last three weeks have weakened the IOD event, however, this is most likely to be temporary. A majority of the five climate models surveyed by the Bureau predict the negative IOD will persist into November. A negative IOD increases the chance of above average winter–spring rainfall for much of southern and eastern Australia.

The Madden–Julian Oscillation (MJO) is currently in the western Indian Ocean, where it has remained since early August. This phase of the MJO typically sees increased cloudiness over the Southeast Asian parts of the Maritime Continent and eastern Indian Ocean, along with enhanced easterly wind anomalies, which may have acted to weaken the negative IOD. Forecasts generally indicate a weak MJO will progress eastwards across the Indian Ocean in the coming week.

The Southern Annular Mode (SAM) index has been positive over the past week and is forecast to remain so for the next fortnight. A positive SAM typically has a drying influence on south-west and south-east Australia during winter, and enhances chances of above average rainfall over much of New South Wales during spring.

Climate change continues to influence Australian and global climate. Australia's climate has warmed by 1.44 ± 0.24 °C over 1910–2019, while southern Australia has seen a reduction of 10–20% in cool season (April–October) rainfall in recent decades.

Next Climate Driver Update expected on 14 September 2021.Climate Driver

Daily maximum temperature extremes graph for Australia: 1 January to 31 August 2021

Above median spring rainfall likely for eastern two-thirds of Australia

Issued: 26 August 2021

• Rainfall for spring (September to November) is likely to be above median for south-east WA, the NT, SA, Queensland, NSW, Victoria and eastern Tasmania (chance of exceeding median is greater than 60%). Much of the eastern States show a greater than 80% chance, as does eastern parts of the NT and SA. Conversely, parts of western WA and south-west Tasmania are likely to have below median rainfall (chance of exceeding the median is less than 40%).

• The pattern for the months of September and October is similar to the spring outlook, though the likelihood of exceeding the median rainfall is not as high in the eastern two-thirds of the country, and extends further west into eastern WA for September.

• Rainfall for October to December is likely to be above median for the eastern half of Australia, and below median for north-west WA.

• Past accuracy (Opens in new window) for September to November rainfall is high to very high for most of the eastern two-thirds of Australia, with moderate accuracy for central and eastern Victoria, most of WA and the central NT shifting to low accuracy for central areas of WA.

BOM September 2021 rainfall outlook: Taree to the NSW-Qld border

Yes, it's been a bit wet recently...

On Thursday 7 January 2021 the Yamba Pilot Station recorded a total of 34.4mm of rain and this was followed the next day by rainfall of 22.8mm.

Up to 11 January 2021 the pilot station recorded a total of 81.9mm of rain. 

The Daily Telegraph, 11 January 2021:

Last year was a hot and wet one for the Clarence Valley, with some rainfall records broken and above average temperatures recorded.

According to the Bureau of Meteorology, Wooli Beach set a new record in total rainfall, with 2201.6mm recorded in 2020, eclipsing the previous record of 2004.8mm in 2011.

Grafton Research Station also had its wettest year since 1959, with 1600.2mm recorded.

Yamba’s Pilot Station had 1746.6mm of rainfall in 2020, which was about 20 per cent higher than the average annual rainfall total for the station.

Grafton Airport AWS had a total of 1527.8mm last year, a 33 per cent increase on the station’s rainfall average.

Meanwhile, Grafton experienced its third driest November since 1917 with just 7mm of rain recorded, immediately followed by its wettest December in 164 years of data, recording 513mm.

BOM senior climatologist Dr Lynette Bettio said for NSW, rainfall was above average for most of the state.

“That was a real contrast to what we saw in 2019 with those extreme drought conditions across the state,” she said.

“Starting to relieve some of those drought conditions we saw good rainfall at the start of the year which helped out with those winter crops but we do still need to see more rainfall in the coming months to really relieve that long-term drought that we did see in 2019 but it was a good start…..

Tropical Cyclone Uesi predicted to cause damaging seas along Australia's east coast as it weakens

Tropical Cyclone Uesi at Category Two level, Monday 10 February 2020

The Tropical Cyclone Warning Centre Port Vila, Vanuatu, has this particular cyclone tracking south west towards south-east Qld and the NSW North Coast as it weakens.

Weatherzone reported on 10 February 2020 that:

At this stage, there is a fair bit of uncertainty around the movement of this system from Thursday onwards, with a range of plausible scenarios. 
Some forecast models suggest that Uesi will move towards the southwest on Thursday and Friday, which would allow it to move closer to Australia's east coast towards the end of the week. If this happens, the remnants of Tropical Cyclone Uesi, most likely in the form of an extra-tropical cyclone, could cause direct impacts in eastern NSW or southeast Queensland. These impacts could include large and dangerous surf, strong winds and heavy rain. It's worth pointing out that dangerous wind and rain would only occur if the system gets close enough to the coast, while powerful surf can reach Australia even if the system stays well offshore.

The Weekly Times, 11 February 2020

According to the Fiji Meteorological Service, which is tracking Uesi, its current route should take it in a south-westerly direction towards the coasts of both New South Wales and Queensland. It could enter Australian waters as early as Thursday.

The Australian Bureau of Meteorology also says there is a moderate chance the cyclone could turn southwest towards Australia on Thursday — giving odds of between 20%-50% the storm will enter the Coral Sea’s eastern region.

Issued at 2:37 am AEDT Thursday 13 February 2020. 
Refer to Tropical Cyclone Advice Number 7.

ABC News, 12 February 2020:

Tropical Cyclone Uesi could cause more havoc across the NSW coastline later this week, bringing swells of up to 5 metres. 

The news comes as the clean-up continues after the weekend's wild weather. 

The category three cyclone, which is passing north-east of New Caledonia, will track south-west towards the Tasman Sea and could cause increased swells, wind and rainfall as early as Thursday. 

ABC News weather journalist Graham Creed said the cyclone was expected to come closest to the coast on Friday and Saturday. 

"This may produce large swells, which combined with king tides may cause issues for beach erosion, as well as prolong the potential for locally heavy rainfall in showers and thunderstorms," he said....

The forecast at this stage is for swells of about 2 to 3 metres starting on the north NSW coast on Thursday and increasing to 3 to 5 metres on Friday....

By 8pm this evening, Thursday 13 February Cyclone Uesi will have dropped to a tropical low (while possibly maintaining an intensity equivilant to a Category 2 tropical cyclone) and is expected to sit less than 600km to the east of Tweed Heads as the crow flies.

At 2am Friday 14 February 2020 the tropical low is expected to be sitting further south less than 600km to the east of Moonee Beach.

Late Friday night the low will continue to track south before veering further away from the NSW coastline on Saturday.

SEE BOM ADVICE FOR UPDATES AT 
http://www.bom.gov.au/products/IDQ65231.shtml

*Image from Weatherzone, tracking map from the Australian Bureau of Meteorology & animated satellite image from NOAA Environmental Visualization Laboratory

Even the Australian Bureau of Meteorology rain radars are finding they are impacted by NSW bushfires

This tweet is from the Director of ABC News on 6 December 2019:

The ⁦@BOM_au⁩ satellite map over this significant part of NSW suggests desperately needed rain .. but unfortunately, all of the activity picked up here is bushfire smoke. Extraordinary. #NSWbushfires ⁦@abcnews⁩ ⁦@NSWRFS⁩ pic.twitter.com/zZry4r1mLk

— Gaven Morris (@gavmorris) December 6, 2019

Australia 2018: State of the Climate

Australian Bureau of Meteorology, State of the Climate 2018, December 2018:

“Australia's weather and climate are changing in response to a warming global climate. Australia has warmed just over 1 °C since 1910, with most warming since 1950. This warming has seen an increase in the frequency of extreme heat events and increased the severity of drought conditions during periods of below-average rainfall. Eight of Australia’s top ten warmest years on record have occurred since 2005.

The year-to-year changes in Australia’s climate are mostly associated with natural climate variability such as El Niño and La Niña in the tropical Pacific Ocean and phases of the Indian Ocean Dipole in the Indian Ocean. This natural variability now occurs on top of the warming trend, which can modify the impact of these natural drivers on the Australian climate.

Increases in temperature are observed across Australia in all seasons with both day and night-time temperatures showing warming. The shift to a warmer climate in Australia is accompanied by more extreme daily heat events. Record-warm monthly and seasonal temperatures have been observed in recent years, made more likely by climate change.”

DOWNLOAD FULL REPORT (PDF 7.16 MB)

Report at a glance

The Bureau of Meteorology and CSIRO play an important role in monitoring, analysing and communicating observed changes in Australia's climate.

This fifth, biennial State of the Climate report draws on the latest monitoring, science and projection information to describe variability and changes in Australia’s climate. Observations and climate modelling paint a consistent picture of ongoing, long term climate change interacting with underlying natural variability.

These changes affect many Australians, particularly the changes associated with increases in the frequency or intensity of heat events, fire weather and drought. Australia will need to plan for and adapt to some level of climate change. This report is a synthesis of the science informing our understanding of climate in Australia and includes new information about Australia’s climate of the past, present and future. The science underpinning this report will help inform a range of economic, environmental and social decision-making and local vulnerability assessments, by government, industry and communities.

Key points

Australia

·         Australia's climate has warmed just over 1 °C since 1910 leading to an increase in the frequency of extreme heat events.

·         Oceans around Australia have warmed by around 1 °C since 1910, contributing to longer and more frequent marine heatwaves.

·         Sea levels are rising around Australia, increasing the risk of inundation.

·         The oceans around Australia are acidifying (the pH is decreasing).

·         April to October rainfall has decreased in the southwest of Australia. Across the same region May–July rainfall has seen the largest decrease, by around 20 per cent since 1970.

·         There has been a decline of around 11 per cent in April–October rainfall in the southeast of Australia since the late 1990s.

·         Rainfall has increased across parts of northern Australia since the 1970s.

·         Streamflow has decreased across southern Australia. Streamflow has increased in northern Australia where rainfall has increased.

·         There has been a long-term increase in extreme fire weather, and in the length of the fire season, across large parts of Australia.

Global

·         Concentrations of all the major long-lived greenhouse gases in the atmosphere continue to increase, with carbon dioxide (CO₂) concentrations rising above 400 ppm since 2016 and the CO₂ equivalent (CO₂-e) of all gases reaching 500 ppm for the first time in at least 800,000 years.

·         Emissions from fossil fuels continue to increase and are the main contributor to the observed growth in atmospheric CO₂.

·         The world’s oceans, especially in the southern hemisphere, are taking up more than 90 per cent of the extra energy stored by the planet as a result of enhanced greenhouse gas concentrations.

·         Global sea level has risen by over 20 cm since 1880, and the rate has been accelerating in recent decades.

·         Globally averaged air temperature has warmed by over 1 °C since records began in 1850, and each of the last four decades has been warmer than the previous one.

Future

Australia is projected to experience:

·         Further increases in sea and air temperatures, with more hot days and marine heatwaves, and fewer cool extremes.

·         Further sea level rise and ocean acidification.

·         Decreases in rainfall across southern Australia with more time in drought, but an increase in intense heavy rainfall throughout Australia.

Too warm, too dry as Winter draws closer to Spring in Australia 2018

Australian Bureau of Meteorology (BOM), 12 Jly 2018:

Warmer days and nights favoured for August–October

August to October days and nights are likely to be warmer than average for most of the country, with high chances (greater than 80%) in eastern Victoria and NSW, and southern Tasmania.

Days and nights in August are likely to be warmer than average for most of Australia, with high chances (greater than 80%) of warmer days in the southeast.

Historical accuracy for August–October maximum temperatures is moderate for eastern and northern parts of Australia, as well as southern WA. Elsewhere, accuracy is low to very low. Historical accuracy for minimum temperatures is moderate for the northern half of Australia, SA, and Tasmania, but low to very low elsewhere.

Temperature - The chance of above median maximum temperature for August to October

Drier than average August–October likely in northeast and southeast mainland

August to October is likely to be drier than average in Victoria, NSW, southeast SA and northeast Queensland

The August outlook shows most of Victoria, NSW and Queensland are likely to be drier than average.

Historical outlook accuracy for August to October is moderate over most of the country, except for interior WA, where accuracy is low to very low.

Rainfall - Totals that have a 75% chance of occurring for August to October

Drought

June rainfall was below average for most of Australia, and very much below average for parts of the east coast

The start of the southern wet season has been drier than average

Rainfall deficiencies persist in both the east and west of the country, increasing in the east at the 6- and 15-month timescales, and along the west coast at the 15-month timescale

Lower-layer soil moisture was below average for June across most of New South Wales, the southern half of Queensland, South Australia, the Northern Territory, the Kimberley and the south of Western Australia

Soil Moisture

Soil moisture in the lower layer (from 10 cm to 100 cm deep) for June decreased over eastern Australia, and increased over parts of northwest Western Australia following above average rainfall for June.

Lower-layer soil moisture was below average for the Kimberley and southern Western Australia away from the west coast, most of South Australia and the Northern Territory, New South Wales and eastern Victoria, southern and eastern Queensland south of a line between Birdsville and Townsville, and along the coastal fringe of eastern Cape York Peninsula.

Map of lower level soil moisture for the previous month

NSW Dept. of Primary Industries, NSW State Seasonal Update - June 2018. Click on map to enlarge:

Tweed, Richmond, Kyogle, Lismore, Byron Bay, Ballina, Clarence Valley local government areas, as at 15 July 2018 according to Combined Drought Indicator:

The entire Northern Rivers region is considered drought affected.