SA - HARVEST OUTLOOK

Lets get straight into the outlook for the coming 6 weeks and look at the range of weather impacts on your property based off the latest data.


Remember the further you go out, the less reliable the guidance gets, however we have had a fairly persistent wet and cooler signal with elevated risks of severe weather.


% chance of exceeding the median rainfall for the period October 24-December 6 2021

There has been not too much change from the previous update, the higher than average rainfall connected to the Indian Ocean Dipole will run through the northwest of the nation, throughout the tropics and into the southeast states, lifting the chances of rainfall. There will also be influence from the ongoing increase of temperatures in the tropical waters over northern Australia. This is leading to above average rainfall over northern Australia and this is being projected southwards as upper level winds turn more easterly and northerly through the month of November. This will also lead to an increase in severe weather risks the further east you live in the nation. The weather very humid as well through northern and eastern Australia and again this will be transported south and east. Overall a wet month for the nation, starting out of the gates with a stormy start to November which will persist for much of the month for northern WA, the NT, QLD and NSW. Occasionally wet and humid for SA and VIC and the southwest of the nation likely to see seasonal conditions.

% chance of exceeding the median temperatures for the period October 24-December 6 2021

No change from the previous update, with the warmer bias continuing over the northern and eastern areas of the nation and the southwest continuing with the cooler Spring. The weather over the eastern inland may be cooler than normal at times with more rainfall and cloud cover leading to lower temperatures. The northern tropics may see some moderation to the high heat values as we go through the month and into December.

Severe Thunderstorm Risk November

The most active severe weather is expected further north and east of the Ag Areas. That is good news for those salvaging what they have for harvest. The active weather connected to troughs and deeper moisture over inland and eastern Australia. That does not mean that the odd storm outbreak won't impact areas further south, it is just more likely to occur over interior regions.

Large Hail Risk November

Large hail risk more likely over the eastern and northeast of the state with a low risk further south over Ag areas for the most part. The hail risk will increase once we see persistent temperatures into the 30s, so as we go through the month the risk will increase with thunderstorm outbreaks. Negligible risk further west towards WA.

Flash Flood Risk November

Higher moisture content means there is a higher risk of severe thunderstorms leading to flash flooding over the northern and eastern parts of the state, again aligned with where the moisture will pool and be in phase with troughs and low pressure. The risk is very low towards the western areas of the state, but again, all it takes is one storm to produce unusual weather and we have seen a lot in areas further north and east throughout the nation and this will seep south through November and December.

Damaging Winds Risk November

Damaging winds will continue to be highest risk over inland areas and to the east of the state where the ingredients to produce robust thunderstorm activity will be found. Thunderstorms have a moderate chance of producing damaging winds this month which is a little above normal for the Ag areas, we usually get more damaging wind risks in December through February.

Frost Risk November

Low risk for Ag areas and mainly early in the month IF we get a cooler blast but at this time it remains very low.

Humidity Risk November

High humidity values over northern and eastern areas could pose risks to crops and livestock, this will clip SA, but areas out over the Riverlands and Murraylands should be aware of the risk of fungal issues moving through the coming month and indeed into Summer as the risk will be increasing. Brown rot and downey mildew for crops and orchards, and irritating conditions for stock that cannot dry out will also be running high moving through Summer coupled with the warmer temperatures.

DATA


RAINFALL

Euro Rainfall Accumulation Ensemble Data - Next 6 Weeks - October 22nd -December 6th 2021

A very wet signal for much of the nation with potential flood risks for the southeast and east with these rainfall values. Higher humidity values and warmer temperatures will increase your risk of mildew, rot and other fungal issues for your crops, particularly those summer crops that are in flower, fruit and at risk of impact from these conditions in the east and south. The severe weather risk from thunderstorms is running high to very high through this period with rainfall likely to be derived from storm outbreaks through the east and periodically, large scale rainfall events sweeping west to east.

Euro Rainfall Accumulation Control Data - Next 6 Weeks - October 22nd -December 6th 2021

This highlights the convective nature of rainfall - it will not end up like this but that is a wet look for the nation running into December.

Euro Rainfall Anomalies - Next 6 Weeks - October 22nd -December 6th2021

That is a VERY WET look or northern Australia with rainfall anomalies 100-200mm above normal for the 6 week period. The rainfall anomalies along the east coast 50-100mm above normal. At this stage most of the nation seeing a 25-50mm increase on normal for this period. That is a wet signal.

CFS Rainfall Accumulation Ensemble Data- Next 6 Weeks - October 22nd -December 6th 2021

We track this daily here, and no change to the signal of wetter bias the further east you go and seasonally it is what you expect as you travel north with the tropics waking up. The tropics are wide awake earlier than normal and this will impact late Spring and Summer rainfall.

CFS Rainfall Accumulation Control Data- Next 6 Weeks - October 22nd -December 6th 2021

The control member way too dry for the north of the nation and through QLD on current guidance from the climate drivers, but that persistent wet signal for the east coast is the theme on this particular product which has carried on this entire week. That is potentially 300-500mm of rainfall for eastern QLD.

GFS Rainfall Accumulation - Next 5 Weeks - October 22nd -November 24th 2021

This model has now fallen into line with the Euro and CMC showing heavier rainfall nation wide which is good to see, that means that we can now prepare for many areas to record above average rainfall and humidity values.

GFS Rainfall Anomalies - Next 5 Weeks - October 22nd - November 24th 2021

Now running wetter than last update which means that the rainfall signal is increasing across the nation.

CMC Rainfall Accumulation - Next 4 Weeks - October 22nd -November 22nd 2021

A very damp four weeks on the way, as advised in the video, your short and medium term forecasts will chop and change I am cautioning all that are making preparations for harvest to be aware of the forecast rapidly changing over the coming week, most likely trending wetter for southeast and eastern Australia. Something to watch.

CMC Rainfall Anomalies - Next 4 Weeks - October 15 - November 14 2021

Very wet look, and it is increasing each update. The west turning wetter now in the latest outlook for the medium term too. Numbers are coming up over SA and into the NT and northwest. This is picking up on the warmer waters right across northern Australia and the IOD.


TEMPERATURES

Euro Temperature Anomalies - Next 6 Weeks - October 22nd - December6th 2021

This is still closest to the post where other models are running too cool or too warm. There is likely to be below average weather for the western interior of WA and through eastern parts of Australia, especially over the coming 1-2 weeks before conditions warm further. We will feel some of that warmer and humid weather this week but then turn cooler and wetter again through November. The battle in terms of temperatures continues. The north will be the opposite, running warm for the coming 1-2 weeks before the rainfall increases. Overall this is indicative of a wet and stormy period with inconsistent temperatures throughout the continent and no especially long run of hot or cooler weather for any one area away from the southwest.

GFS Temperature Anomalies - Next 5 Weeks - October 22nd -November 24th 2021

The GFS is still running way too warm in my opinion, and while it is not impossible as nothing is impossible in weather, it is highly unlikely at this time.

More details to come on this particular product on Tuesday.

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