Farmer climate focus - Sam Becker, Jarrah Cattle Company

Jarrah Cattle Company’s Sam Becker runs a livestock business that includes some forage cropping. The climate and managing groundcover to ensure feed budgets are met, provides the greatest challenge for management.

Sam Becker

Banana, Qld

Location snapshot

Catchment:   Lower Fitzroy Catchment

Altitude:        181 m

Enterprise:    Stud Hereford, Redford and Jarrah Red cattle and forage cropping, including sorghum and oats.

Rainfall:        Wet season (Oct-Mar): 78% rainfall
Cool season (Apr-Sep): 22% rainfall

Seasonal rainfall climate drivers: Banana, Qld

El Nino-Southern Oscillation (ENSO) is the key climate driver, however, ENSO impacts are very weak post-January to May.

What are your ‘go-to’ sources of climate/weather information?

BOM is a big one and we also use The Long Paddock reports supplied by DAF which allows us to see which percentiles we’re sitting in and how much groundcover we have. We also link that in with our records of past rainfall and then looking at the future rainfall as well. I also get a fair bit of information about climate change from social media to be completely honest and then when you read stuff about that and then look at your past three to five year annual rainfall, for example, we’ve been below our annual rainfall for the last five years, so, it’s looking at that to try and find trends. It’s more to find those trends to manage how heavily we stock and where we stock.

How do you consider climate in your farm management?

A big thing we do is try and link our groundcover and rainfall and look at those two things to see if we should be buying or reducing stock. That’s probably been reactive to an extent, but we have also been making decisions on the go, I guess that sort of reflects the decisions that we have made. We don’t want to start with nothing. We want to have groundcover when we go into the wet season and make sure there’s a bit of a body of feed. If there’s nothing there we would have sold. We try to de-stock before we get to that stage, or at least we keep selling off dry cattle to spread our breeders around so that we keep some level of groundcover there.

Can you share a climate success (or failure) story with us?

Probably a failure. In the last five years we were too reactive to the climate. We were selling down, but we probably weren’t doing it quick enough, so we did– particularly with one property – eat it to the ground. We sort of got trapped when the cattle became out of spec, so they became hard sell. We were definitely reactive to that. We had a set number in our heads that we knew our properties could run and we didn’t take into account the last five years with below average rainfall and then the last two which were significantly below. We still, in our minds, thought that we could run a certain amount of cattle which, in turn, lead to one property significantly suffering.  

What’s your soil moisture looking like at the moment?

We’re pretty dry, as in we have had hardly any rain to date since April. So, yes, we are very dry. Not much moisture, not much protein in the soil, we do have a good grass-cover but it’s all dry feed. Because of this we are supplementing our breeding cattle with a fair bit a custom-mix dry lick that is made with our deficiencies and our country in mind.

Do you have altered management plans for the rest of the year considering La Nina has been announced?

We are definitely considering it. It’s now when we consider these trigger points we have that prompt us, depending on how much feed we’ve got, to start selling off dry cattle. This is so we can spread our breeders around so that we keep that good body of feed and then wait until rain comes before we increase our numbers. We’ve made a big effort this year to make sure we start off with good ground cover for the wet season. We definitely aren’t going to start buying in cattle thinking we are going to get good rain, we are going to wait until we’ve had decent rain, the grass has got away and then we would look to build our numbers again.

Have a farming climate story to share? Please contact us.

The co-efficient of variation (CoV) for rainfall helps understand which months are more reliable than others. The chart shows a generally reliable monsoon rainfall, with November as the most reliable month and July as the least reliable month.

El Niño-Southern Oscillation is the major climate driver in the region. An analysis of Oct-Jan rainfall shows some broad trends towards average or better in La Niña years, low rainfall years in most El Niño years and neutral years as completely random.

Developed by the International centre for applied climate sciences https://climateapp.net.au/ has some handy tools to understand the climate for your area.

A summer-dominant rainfall at Banana, Qld. An output of https://climateapp.net.au/

Tracking close to average rainfall for 2020. An output of https://climateapp.net.au/

Climate in-brief

This weeks chart shows humidity well above normal down the centre of Australia.

• Conditions in the tropics, our major source of moisture, continue to be “disorganised” according to the latest NCEP update this week, as the atmosphere continues to realign with warmer tropical waters;

• The SAM index is finally weakly positive, assisting the formation of moist air into eastern Australian agricultural areas;

• 90-day SOI has exceeded La Niña thresholds (+8), and the air pressure at Darwin is now below normal for the first time this season;

• Multi-week models are favouring rain across southern areas and the ranges in the next 10-days. All other areas look to week 3-4 of October for moisture to arrive;

• Summer cropping analysis for La Nina years; and

• What does this years La Nina mean for our climate in 2021? - the latest research.

Australian weekly rainfall and relative landscape water balance

The air pressure at Darwin is finally below normal. Moisture has streamed down the inland over the last week.

Rainfall maps courtesy http://www.bom.gov.au/jsp/awap/rain/

The high pressure system in the Tasman Sea keeping eastern Australia dry, but the interior has been in the sweet spot.

Australian relative landscape water balance ‘upper soil’ courtesy BOM

Climate drivers

Not too much change from last fortnight. The SAM is finally back in positive territory after a month below zero. Research would suggest our climate drivers are in a good state for rainfall across eastern Australia in the coming weeks and months. The 90-day SOI is now in La Nina territory at +8. For those in central-eastern cotton areas looking for rain, a more emphatic positive shift in the SAM and SOI would help prospects.

What to know about the climate drivers and how they are measured? Click here

30-day air pressure anomaly

Why hasn’t it rained? The 30-day mean sea level air pressure shows an intense high pressure ridge sitting in the Tasman Sea, with moisture in recent days streaming down through the red centre into SA and Western Victoria.

https://psl.noaa.gov/map/

Multi-week model survey (8-28 days)

The next genuine chance for rain appears to be in the eastern half of NSW mid-October with northern areas coming online at the end of October through to early November. The Niño 4 SST region has finally warmed up. This index has quite a strong correlation with rain in CQ and Gulf areas in November, so it’s plausible to expect November will be more favourable than October.

Model form: the BOM multi-week model continues the ‘blue kiss of death’ with over-exuberant wet forecasts. Since May if this model were remotely close Keepit and Copeton Dams would be overflowing. Seasonal and multi-week models struggle with systems originating in the Tasman Sea and assume a simplistic east-west moisture airflow. The NCEP/GFS continues to jump around and is showing a colourful system with some strength eventuating across NSW mid-Oct. The IRI model is normally super-cautious and rain across NSW this month adds to confidence levels. NT and Ord cropping zones will have to wait for the end of the month, as the air pressure at Darwin has finally moved below zero.

9-day ECMWF rainfall outlook

Fresh this morning, this European model shows rainfall for the next week in patches around southern areas, northern NSW ranges with storms developing through SE Qld.

Access courtesy https://meteologix.com/au

Monitoring the SAM

Recent research by Hendon et al, (2014) at the Centre for Australian Weather and Climate Research found the Southern Annular Mode to be the leading mode of circulation variability through parts of inland eastern Australia where cotton is grown; particularly in the spring planting period.
 
A positive SAM has been proven to increase moisture supply into fronts and troughs forming in eastern Australia. The chart provided by Climate Prediction Center (US) shows the most recent observations of the SAM or (AAO). 

A negative SAM traditionally leads to a dry westerly circulation pattern through eastern Australian cropping areas.
 
BOM researchers Lim and Hendon (2013) found the SAM has the strongest connection with El-Niño Southern Oscillation in October and November – whereby the SAM is influenced most by El Niño or La Niña conditions.

Growers and advisors are encouraged to monitor the phases of the SAM together with seasonal forecasting, multi-week and short term weather models during planting. A short cartoon explaining the SAM can be found HERE. 

The SAM has been more negative than positive, which stifles East Coast Low (ECL) events along the Tasman Sea. Its been slow to align with the La Nina and wet Modoki phase. Its good to see ECLs popping up off SE Qld in the forecasts, as these events can be game-changers. This is also a key driver for Namoi and Gwydir Valleys, so a shift north of the black line will direct more moisture into those regions.

Antarctic Oscillation or SAM forecast below (25 Sep)

http://www.bom.gov.au/climate/model-summary/#tabs=Indian-Ocean

SOI check

The 30-day SOI remains positive and indicating a La Nina, with the 90-day average firming. The latest technical report from NCEP (US) this week reports a strengthening Walker Circulation (tropical air flow in the troposphere), which acts as a large-scale conveyor belt for moisture reaching Australia. The atmosphere is gradually responding to the warm ocean temperatures.. Darwin hPA is now below 1010, which is a good sign for moisture transport over inland Australia. SOI explained here

Click on the image to see the latest values courtesy longpaddock.com.au

Global tropical hazards

(from U.S Climate Prediction Center)

 A typically stable period for our northern tropics, there are no cyclones or hazards forecast. In contrast the Bay of Bengal and South China Sea is very active. Click on the image to go through to the CPC website.

Cyclone season 2020-21: almost double last years cyclones anticipated

With the Australian cyclone season less than one month away, AccuWeather meteorologists say Australia may have not only a more active tropical season than the last but also one with more storms making landfall on the nation's shores.

During the 2019-2020 hurricane season, the Australian basin produced nine cyclones, slightly below the average of 11, with the first cyclone developing in a late start to the season. Cyclone Blake, which formed off of northwestern Australia on Jan. 4, 2020, came two months after the official start of the season, which runs from November to April.

The first cyclone of this season is expected to form before the end of December, kicking off a potentially more active season for the basin.

For the full article, click here: https://www.accuweather.com/en/hurricane/australian-tropical-season-to-pull-a-topsy-turvy-from-last-year/823466

Summer crop GSR analysis - Lower Namoi/Gwydir

This weeks chart is from CLIMATEAPP. It shows MOREE, NSW YTD rainfall (RED line) ahead of median (Blue line). Click the chart to go through to www.climateapp.net.au and choose your location in ‘hows the season?’

ENSO and rainfall

With so much emphasis on forecast models its prudent to look at statistics under this scenario;

• When the oceans are in this state (RHS image) there is a high probability that above median rainfall will occur in the next 4 month period at Burren Junction;

• A La Nina condition has profound affects on the Rowena growing Season Rainfall at Rowena. The botton chart shows La Nina (dark blue), neutral (light blue) and El Nino (red) state, based on a fairly couse assumption on the Nino3.4 index at years end;

• With LT average for that location being around 288mm, the worst case scenario over the analysis period looks to be average, with many La Nina totals well exceeding average;

• Post-January, the correlation with ENSO decays and other factors such as the MJO take over.

Chart courtesy AgEcon and BOM climate data online

Different flavours of La Niña - a word of caution

While scientists monitor the magnitude of cooling SSTs across the ENSO regions for La Niña strength, one could easily assume a moderate-to-strong event equates to “lots of rain, just on what scale”. Commentary from international experts this week helps to explain the nuances among La Niña events, and how each occurrence differs in terms of rainfall.

2010 v 2020 SST distribution (top image, below) shows cooler waters in the Coral and Arafura Sea regions now (red circles), when compared with 2010. These are key zones for convective moisture, feeding into northern area agricultural areas.

The 2020 La Niña, characterised by cooler waters through the Maritime continent north of Australia, are believed to be more similar to events occurring in the 1980s rather than signature events of 1998 or 2010. Whilst analogue year and statistical analysis has its critics, its useful to revisit Nov-Jan rainfall in those years.

• 1983-84 La Niña rainfall (Nov-Jan) shows NSW, SA and Southern Qld in the sweet spot with a north-west moisture flow from a warmer Indian Ocean, and drier in the tropics.

• 1988-89 La Niña rainfall (Nov-Jan) shows the main beneficiaries of the event occurring in NSW and SA, with much of Qld not achieving average 3-monthly rainfall.

At this stage, guidance suggests from a tropical forcing perspective, the 2020-21 La Niña is expected to have more activity through the Eastern Indian Ocean and less over the Maritime Continent (north of Australia). Under this scenario, summer rainfall potentially favours the mid-latitudes rather than the tropics and northern Australia.

SOI check

The 30-day SOI remains positive and indicating a La Nina, with the 90-day average firming. The latest daily air pressure values suggest the SOI shift is more related to higher pressure over Tahiti rather than Darwin. We would prefer to see the Darwin hPA contribution drop some more to encourage more moisture flow over inland Australia. SOI explained here

Click on the image to see the latest values courtesy longpaddock.com.au

Apple’s ‘Weather’ App

Pre-loaded on every iPhone – just how good is it?

Accuracy:     High Accuracy (according to global reviews we could find). Data is drawn from The Weather Channel (An IBM Business) which incidentally
has its own app. 

Cost:           FREE

Features:     A simple to read

                        Current weather conditions

                        Hourly forecasts for the next 24 hrs

                        10-day forecast

                        Quick swipe to view saved locations

                        Click through to The Weather Company which has further detail, but is full of ads

Pros: Hourly updates. This is a separate computer than the usual BOM and other suspects, which can offer a new perspective on a change coming.

Cons:          No ability to get further detail. No probabilities of precipitation or winds.

Overall:        A simple, yet accurate app that can give a quick overview of conditions.

Farmer climate focus - Janine & Christian Powell

Ag Econ’s Janine Powell lives with her family on a farm near Burren Junction. Her husband Christian is part of a family farming operation that is focused around dryland and irrigation farming enterprises, the climate is a huge consideration in their business.

Location snapshot

Catchment:   Namoi Valley (Murray Darling Basin)

Altitude:        163 m

Enterprise:    Broad acre dryland, irrigated farming and livestock

Soils:             Cracking grey vertosols (Plant Available Water 200mm)

Rainfall:        Wet season (Oct-Mar): 63% rainfall
Cool season (Apr-Sep): 37% rainfall

Seasonal rainfall climate drivers: Burren Junction, NSW

Janine & Christian Powell

Burren Junction, NSW

“As broadacre farmers we feel beholden to the weather. Recently it has been too dry, sometimes too wet… rarely do we get the Goldilocks experience of the weather being ‘just right’” Janine explains.

On farm the Powells take into consideration long-term forecasts for planning crop rotations and plantings. While these forecasts can give a good indication of potential climatic patterns, they are well aware that it is not a guarantee of getting (or not getting) rain.

The Powells have a winter cropping program which includes cereals and pulses. “With the wetter 2020 Winter Spring seasonal model forecast in mind, this year we capitalised on the rain that fell in Feb-April by planting all our dryland area to a mix of winter crops”. Like many other farms in the region, it is the first time in 4 years since the full area has been planted.

“Some of our country is slightly undulating with poor drainage, so we hope it’s not a wet at harvest… at this point it’s looking that way.”

“It’s important to understand which factors drive the climate in our region to better manage risk – particularly during our winter cropping growing season”.

Climate literacy allows farmers like the Powells to consider potential climate risks and how they can be mitigated. “With the wetter outlook, we did contemplate leaving out some of our lower laying paddocks fallow but decided the opportunity cost was too high. Instead we planted those areas to lower cost cereals – if they get waterlogged or even flooded prior to harvest – we won’t have lost too much money.”

The Powells utilise silo bags for temporary on farm storage. “In the past we’ve ensured they were on raised pads and in accessible positions for trucks. This year we are looking at increasing the size of the areas allocated for the bags and potentially improving the road accessibility to some of them.”

When asked which rainfall models they look to for shorter forecasts they both use Meteologix. “It’s a great overview of what many of the international models are predicting, I like to take a rough average of the models as an indication, but the high and low also give a potential range of what you might expect.”

This year to date the Powells have had 392 mm of rain. May and June turned out dryer than expected with a total of just 25 mm. Rainfall for July and August totalled 74 mm and they have their hopes on high September rainfall to finish the winter crop.

“During rainfall events we are glued to the BOM radar and then afterwards we are on OzForecast seeing where the rain fell locally.” Janine likes looking at the broader BOM image of the state or Australia image to see the overall movement of the system, whereas Christian likes to be zoomed in to see where (and on who’s farm) the rain is falling. The Powells recently installed a Davis weather station that is linked to the OzForecast network to see real and accurate on farm weather data. “The purchase may have also been prompted by one too many disappointing instances of the gauge over reading due to an ill placed sprinkler!”

“Certainly, for the bigger picture it’s important to have an understanding of the cyclical nature of Indian ocean Dipole and El Niño-Southern Oscillation phases. Access to good quality climate information can help our farming business make better decisions, more often”.

Across Australia the 2020 Winter crop is forecast at 47.9 million tonnes 64% higher than last year and 20% higher than the 10-year average (ABARES September Crop Report). Janine is encouraged by this outlook, “A decent winter crop will be a real help to Australian farmers, the Ag sector and the broader Australian economy – it’s what we all need”.

Have a farming climate story to share? Please contact us.

January 1st 2020, Dry rivers and wondering if it will be another cropless year

Planting in APRIL on the back of good rain Feb-Apr

September crop inspection - Faba beans

September - the faba beans are filling the pods.

Meet the researcher

Jon Welsh

Farmer Forecast lead climate analyst

When and why did you become interested in climate?

I came home to a mixed farming business at Walcha in the mid-1990s which ended up adding a block at Coolah in the central west five years later. 1994 was my first year on the farm, which was coined a ‘once in a generation’ drought - technically every 25 years. When you own livestock, protracted droughts can be gruelling, physically and emotionally. More so with cattle that eat the drought feed as quick as a bank can print the money. My father would not sell into a depressed drought affected cattle markets, so we fed, fed, fed, and lopped kurrajong scrub. Dry times in 1994, 2002, and the first half of 2005 then another drought of 2006 and a near record breaker of 2009 seemed more than bad luck. During the contrasting 2005 dry first half and wet second half of the year I started to wonder if science could help anticipate these emphatic shifts and that our farm’s fortunes were driven by the climate. Waiting for natural springs to break out and truck drivers giving advice on Bogong moth sightings was not working on a farm management level.

So, was it simply the toll of feeding cattle that motivated you?

“our cattle in One of the many drought years, which, in hindsight, had strong correlations with both the Modoki index and IOD. If only I knew then what I know now”

Yes and no. Yes, because when you started feeding it was nearly impossible to know when to stop. We fed all our cows through a dry time for 10 months, sold them - then it rained cats and dogs 8 weeks later. Feeding over long periods costed a fortune and we almost gave back all the profits we made the year before when the dollar sunk to 45c (and stock prices were at record high levels). No, because the ‘once in a generation’ droughts that were meant to be 25 years were happening every 5 years or less. Old timers in the district used to shake their heads and say, ‘things were never like this’. The annual rainfall at Coolah could vary from 350mm to 1200mm in any given year. We used to budget for 28” but I don’t think we ever hit near that number in 13 years we were at Coolah. We bought a black soil grain farm and sold the grain crop on it for $130/t when grain was everywhere in a great season. No rain for 6 months followed, and we bought grain back to feed stock for $300/t. If science could help, then decisions to buy and sell stock and grain would be more informed – rather than simply a game of Russian Roulette.

What was your first step in understanding climate science?

There was 35 years of historical on-property rainfall records at Coolah and I started to compare them with climate cycles. I started to search online and find out about El Niño and La Niña which I thought was complete hocus pocus and witchcraft at the time. That preconception was mainly from 1997 touted as the El Niño ‘event of the century’ which was a good year with a wet spring. I cold-called CSIRO oceanography research in Hobart. I was dusty and stressed one lunch time with no end to the drought in sight. I was transferred by the receptionist to Dr Mike Pook who was very helpful, and we had a cordial chat. I was encouraged he gave airtime to a complete stranger. He then suggested I investigate the research done by ‘a bunch of scientists in Japan’ who had done some neat analysis on the Indian Ocean and the effects on the Australian climate. So, I scribbled down a Japanese surname and a research agency in Tokyo. With that encouragement I looked up the telephone country code of Japan and made an international call. To my surprise the receiver (Prof Toshio Yamagata) spoke broken English and was happy to discuss his findings. Our conversation centred around the Australian drought and farmer suicide here that must have made international news at that time. I was heartened once again and continued my climate investigations. After thinking excel was a brand of planter, I put the 35 years’ worth of monthly data into a spreadsheet as requested and sent it via email to the Japanese Agency for Marine Science and Technology (JAMSTEC). The climatic analysis that eventuated from the Japanese researchers aroused my interest in climate science and Australian rainfall.

In 2009, Japanese national broadcaster NHK, flew out to Australia to report on a farmer using Japanese research to manage droughts. The Australian Bureau of Meteorology first referred to the Indian Ocean Dipole in climate analysis in 2013

Speaking at an APEC international climate symposium in Japan – how did that happen?

In 2008 I was in routine communications with Dr Behera Swadhin, a colleague of Prof. Toshio at JAMSTEC, Japan. Halfway through the year they asked me to talk at the upcoming climate symposium at Tokyo University on “Impacts of the Indian Ocean on SE Australian Agriculture”. I did not know what it all meant but it was an expense paid trip and I figured nobody in Japan would understand me anyway, so nothing to lose. For the presentation, I managed to convince the local Graincorp contact to release some site-specific receival data from various silo locations in NSW and did some basic regression analysis on annual grain intake and Indian Ocean Indices, with the help of my Japanese mentors. I then muddled my way nervously through the 40 minutes on stage at Tokyo University. It was a relief when the presentation was over. The hospitality shown, the tours of JAMSTEC and seeing the huge climate supercomputer in Yokohama was quite an experience.

Tell us about your move into cotton research and climate extension?

The move into climate research and extension is a complete accident. Family farming businesses are complex and transitioning between generations, while accounting for siblings rarely goes in a straight line. I ended up in Narrabri in 2013 without a job and met with Cotton Research & Development Corporation for a position that included a climate extension component. With that, came a well-resourced project and very supportive cotton R&D Managers: Dr Ian Taylor and Allan Williams who instilled free-thinking and a no-limits approach to finding out whatever I needed to wherever I needed to look. I was informed the only other personnel on the project register was NSW DPI research economist from out west of Wee Waa somewhere, Janine Powell. The 4-year CRDC project gave access to CSIRO researchers, universities, international research contacts, extension specialists nationwide, conferences, as well as exposure to climate R&D among a host of other things. A new business eventuated with Janine as founding partners from the previous project, to what is Ag Econ and Farmer Forecast currently. Climate ‘researcher’ tag given in this interview is probably not as apt as climate ‘survivor’.

“A late La Niña condition finally arrived after another dry winter. A bin-busting pioneer G33 sorghum crop, pictured with agronomist, James Miller”

What areas of climate extension and research are you involved in now?

As part of the ongoing CRDC role, distilling relevant information sources for decision making for cotton growers and advisors currently covers traditional NSW and Queensland areas, but is now shifting into the tropics, which is exciting. Post-graduate lecturing at UNE and course content on agricultural climate risk management is currently in its 7th consecutive year as well as routine workshops with agronomists at decision times, also communications to Local Lands Services. In terms of climate research, the bulk of time commitment is spent on reviewing existing journals and planning new research projects for cotton and other RDCs via the Managing Climate Variability program including MLA, GRDC, SRA and AgriFutures – mainly for relevance and application to farming. However, there is some applied research coming through the pipeline I am involved in with UNSW and CSIRO, which we hope to publish in scientific journals this year.

After increasing your climate literacy over the years how has it affected your attitude to risk and farm decision making?

Partners can live in a marriage their whole life and never understand the opposite sex. In the same vein, farmers can live with the climate their whole life and not understand it, simply accept it. From my experience there have been wins and losses on the farm over the years trying to anticipate broad scale shifts in the climate, particularly when the lure of super profits beckons from a good trade. I bought a sizeable cotton seed contract once that increased 400% in six months on a dry forecast, purchased cattle for $1/kg at the end of a drought which made super profits before it rained. But there have been losses as well. Forward selling a portion of Faba Beans during a wet harvest ended in disaster after 300mm - which isn’t easily forgotten. The commodities market is clearly better educated on climate than it was 10-15 years ago, without as many short-term wild swings in prices. Climate knowledge has without doubt, helped manage our livestock numbers and manage risk over the last 3 years. With a decent standard of climate literacy, I am probably more cautious now on decisions than ten years ago - relying on black cockatoo sightings and new growth appearing on river red gums was a fools paradise. I’m not sure there’s ever a pot of gold awaiting seasonal forecast info, but it can certainly can help stop bad decisions when the evidence is there.

New research – summer rains in the mid-latitudes

The study has found that the influence of climate change and the depletion in stratospheric ozone are the major drivers over the Atlantic Oceans that shift the westerly winds further south. However, over the Pacific and Indian oceans, natural variations induced by sea surface temperature changes in the tropical Pacific also play an important role in the southward shift and can intensify these winds in the southwest Pacific Ocean.

A major component of this natural variation is the Interdecadal Pacific Oscillation (IPO). This is a shift in the state of sea surface temperatures, air pressure and wind direction over decadal timescales. The study found that the state of the IPO in the early-21st Century led to warming in the subtropics and mid-latitudes, which increased the generation of transient eddies at around 55°S, acting to strengthen and shift the winds south. Changes in the Southern Hemisphere westerly winds have profound impacts on Southern Hemisphere rainfall patterns, the Southern Ocean and Antarctica. Understanding the mechanisms that create these wind shifts has significant implications for prediction of Southern Hemisphere climate over the coming decades.

Paper: Yang, D., Arblaster, J. M., Meehl, G. A., England, M. H., Lim, E. P., Bates, S., & Rosenbloom, N. (2020). Role of tropical variability in driving decadal shifts in the Southern Hemisphere summertime eddy-driven jet. Journal of Climate, (2020). https://doi.org/10.1175/JCLI-D-19-0604.1

Key climate indices: ENSO & Indian Ocean

Refreshed global models are showing consensus for the Niño 3.4 region to stay outside the -0.8 SST threshold in La Niña territory. Some of the international analysts are calling for a stronger, more intense event now and one global expert has put himself out there by calling for back-to-back La Niñas in 2021-22. The typically erratic Indian Ocean Dipole is making a run for wetter phase, which will certainly help, but is unlikely to over-ride the main ENSO influence prior to decaying in November.

Bureau of Meteorology modelling 14 September

http://www.bom.gov.au/climate/model-summary/#tabs=Indian-Ocean

Global tropical hazards

(from U.S Climate Prediction Center)

 A typically stable period for our region, there are no tropical hazards forecast. In contrast the Atlantic has already experienced a record breaking amount of activity this hurricane season (Jun - Nov). Click on the image to go through to the CPC website.

Seasonal forecast: October - December 2020

Form: Coming out of a dreadful run of form from a wet winter that didn’t eventuate for central/northern areas, GCMs are keeping in-step with the developing La Niña signal with cool, wet conditions throughout the forecast area. The only model a bit less bullish on a solid wet signal was UK Met, whereas the IRI was heavy on the tropics copping a wet time in the coming three months.

What to know more about the climate drivers and how they are measured? Click here