HARVEST OUTLOOK AND FARM FOCUS WEATHER.

As always on a Tuesday, I update the latest Harvest Outlook Forecast and talk farming impacts.


So lets get straight into it.

FORECAST

Rainfall Outlook Next 6 Weeks - November 2nd 2021 - December 18th 2021

% chance of exceeding the median rainfall for the coming 6 weeks

The wet signal continues for most of the nation. The takeaway from the guidance and data sets is that the harvest period will be likely disruptive, you will be dodging and working around rainfall and thunderstorm outbreaks from this week right through to the middle of December. Your rainfall amount will vary as we have seen in recent weeks, but the signal for above average rainfall as a whole is very high for northern and eastern parts of the nation, the further west and south you go, the risk of above average rainfall starts to diminish. Watch the Indian Ocean influence, the developing La Nina conditions and the persistent positive SAM phase, the SAM being the short term driver for rainfall through QLD and NSW. That could really enhance rainfall chances.

Temperature Outlook Next 6 Weeks - November 2nd -December 18th 2021

% chance of exceeding the median temperatures for the coming 6 weeks

No change from Friday's update, the data sets have trended colder in recent weeks and I am leaning towards that solution given the amount of moisture, cloud and rainfall forecast during this period. We have multiple ports of moisture coming from the Coral Sea through the northern tropics and from the Indian Ocean, all pooling into the nation, this seeing the rainfall signals increasing and thick cloud cover persisting for days at a time. The weather is not expected to be cold over central and eastern areas, but more likely humid and unsettled with rainy skies more often than not. The southwest of the nation is expected to see cooler and drier air with onshore southwest winds thanks to persistent ridging. The northern tropics will see temperatures moderate over the coming 2 weeks, the last of the very high heat values concluding this week.

Humidity Outlook Next 6 Weeks - November 2nd -December 18th

% chance of exceeding the median humidity for the coming 6 weeks

Higher humidity values against the average continues to be observed throughout the north of the nation and is now spreading south and southeast this coming week. The moisture on some of the modelling coming through is expected to hang up over large parts of the nation's northern and eastern states. This will contribute to showers and thunderstorms becoming widespread as mentioned above, however the impacts to crops in the humid and warm weather with the rainfall could be quite high as many farmers wait to get them out of the ground. The further south and west you go through the nation, there will be breaks in the humidity. The further north and east you go, the longer duration of humidity and warmer weather with rainfall frequent.

Disease Outlook - November 2nd - December 18th 2021

High humidity and warmer weather coupled with a high risk of above average rainfall and cloud cover will lead to a high risk of disease to crops, especially crops that are in the ground. Vingerons should be on alert for Downey Mildew. Orchardists should be aware of the risk of brown rot and other fungal issues with the higher humidity forecast. Cereal crops ready for harvest also at risk from the myriad of fungal issues as we move into a soupy period. The west sees a lower risk for the SWLD with persistent ridging and onshore southwest winds keeping the weather dry and mild with lower risk of humidity issues for now.

Severe Thunderstorm Risks to Farming Next 6 Weeks - November 2nd - December 18th 2021

A high to very high risk of severe thunderstorm outbreaks for northern and eastern Australia. Large hail is still a significant risk through this period for NSW and QLD in particular but as the atmosphere becomes more humid to saturated through the month, the risk of hail decreases and the flash flood risk takes over as the main concern and I think we will transition towards that during this period. Stay weather aware and make sure you keep up to date with all the daily forecasts for your state here. I am covering it daily and pumping out the charts with as much detail as possible so you can have as much information as possible through this period.

Large Hail Risk November 2021

This risk offers a lot of anxiety for many in the east and southeast but fingers crossed we transition to the wetter and cooler phase earlier to offset this risk below.

Queensland

South Australia

CLIMATE DASHBOARD

No change to the guidance in the climate models once again which is good, the Indian Ocean is peaking in it's negative phase and we are seeing that impact on the overall short and medium term forecasts with moisture streaming in from the northwest into the tropics and then southwards into the interior. This influence will continue for the coming 4-6 weeks across the nation. The SAM is currently positive and expected to stay that way, increasing rainfall chances along the east coast as you can see in most data sets below. Finally the ENSO is likely to shift into La Nina during the latter part of November into December, HOWEVER, the shift into the La Nina and the impacts felt in Australia, usually has a lag of about 4-6 weeks and so this is likely to be experienced after Christmas at this stage over the continent.

DATA - Refer to video for more on these sets of data


RAINFALL

Euro Rainfall Accumulation Ensemble Data - Next 6 Weeks - November 2nd -December 18th 2021

Rainfall bias has not changed for the nation from last week. The northern and eastern areas of Australia to experience the wettest weather through this period. The early onset rainfall forecast from July has now begun to verify, with near record rainfall being observed in some locations of the NT and eastern WA. This is a very wet look for the period and this will have heavy impacts on crops and yields this year. We have already seen the impact from the severe weather events in recent weeks and this will continue to impact large parts of the nation. Disease risks also running high in the long duration humidity events. The southwest and west looking drier under persistent ridging.

Euro Rainfall Accumulation Control Data - Next 6 Weeks - November 2nd-December 18th 2021

The control member is one data set with heavy falls being shown through QLD and the NT still and extending south and southeast through the nation. There is also evidence that data is spreading the rainfall into northern WA which could feed the heat trough out west, with showers and storms becoming more frequent over the outback. Note this is one data set. The above is 51 data sets! So the signal is overwhelming wet and humid.

Euro Rainfall Anomalies - Next 6 Weeks - November 2nd -December 18th 2021

Rainfall anomalies are running very much above the average throughout the nation with again the drier bias over the southwest which is normal. But the weather cooler under the persistent ridging. The humid and rainy weather will have huge impacts over the central and eastern parts of the nation thanks to a persistent trough and low pressure coming through southeast and eastern parts of the nation lifting the deep moisture profile into frequent showers and thunderstorms. There could be record rainfall values through November in some locations of Northern, Central and Eastern Australia. On current guidance that risk has increased in the latest data sets in this morning.

CFS Rainfall Accumulation Ensemble Data- Next 6 Weeks - November 2nd -December 16th 2021

The bias of the rainfall is over the southeast and east of the nation and again note the tropical connection of rainfall extending through the NT into SA and then into the southeast. The drier bias is over the far west and southwest set to unfold with a persistent ridge which is what we are seeing this week.

CFS Rainfall Accumulation Control Data- Next 6 Weeks - November 2nd -December 16th 2021

Significant rainfall over the east and southeast of the nation in response to the tropical activity and early onset rainfall, however this model does not cope well with tropical rainfall forecasts, so with that said, that may mean the rainfall over the east on this particular model is being under forecast. But the bias of heaviest rainfall over the southeast and east of the nation continues as well over the Central parts of the nation where moisture will become stagnant and be lifted into widespread showers and thunderstorms.

GFS Rainfall Accumulation - Next 5 Weeks - November 2nd - December 5th 2021

We have seen the moisture deepen in the past week and the coverage of rain and thunderstorms increase with many areas over the northern parts of WA through the NT and into QLD seeing widespread falls, some heavy. The rainfall over the east coast will likely be connected to the positive SAM phase and the persistent onshore flow which we can see developing on the short and medium term forecasts at the moment. The outback rainfall could be significant and lead to record November falls. The weather over the SWLD is expected to be drier under ridging.

GFS Rainfall Anomalies - Next 5 Weeks - November 2nd - December 5th 2021

The outback rainfall prognostics are significant and paint the potential for points east and south down the line from this region, wet and humid weather to establish over much of the nation, can feel it in the air today over the east and the southeast will feel it tonight and tomorrow and that will feature frequently through the coming 4-5 weeks. Rainfall signals over the NT are excessive with 5-8 inches above the usual expectations very significant. That wiil increase the risk of above average rainfall over the remainder of the nation moving through November into December, again we see this happening now.

CMC Rainfall Accumulation - Next 4 Weeks - October 28th -November 29th 2021

This was updated on Friday. The latest data set off the CMC for the coming 4 weeks is very wet, these values are higher than what we saw last year heading into a La Nina year with the waning negative IOD, so there is some cause for concern if you are looking for dry and settled weather to get the crops out, you will be hard pressed to find a stretch of dry weather over central and eastern Australia. Better luck exists back in the SWLD of WA but even there, it is wetter than normal.

CMC Rainfall Anomalies - Next 4 Weeks - October 28th - November 29th 2021

The anomalies over the coming 4 weeks very much above the average, the blue shading is 2-4 inches (50-100mm) above the normal rainfall you would see during this time frame! So that is going to place some areas under significant humidity, rainfall and storm impacts, especially those harvesting through central and eastern Australia. The west cooler and damp but not as wet. The tropics, very active fueling the wild weather.

TEMPERATURES


Euro Temperature Anomalies - Next 6 Weeks - November 2nd - December 18th 2021

A cooler trend in the modelling and this particular run has turned colder than the earlier data sets this week. This is in line with the higher than average rainfall forecast for much of the nation, northwest to southeast movement of rainfall through the interior, to suppress the temperatures exceeding the values. The guidance is unchanged from last week as we move into Christmas, so expect not too many hot dry days in the coming weeks.

GFS Temperature Anomalies - Next 5 Weeks - November 2nd- December 5th 2021

This is still running a little warm and is the outlier for the east and southeast. It is running warmer in the shorter and medium term data as well. Something to watch but more unlikely in coming off. The southwest and west of the nation, cooler under the ridging

CMC Temperature Anomalies - Next 6 Weeks - November 2nd - November 29th 2021

The CMC running cooler than normal for the west of the nation which is in good agreement with the data above and that extends into the central and eastern inland of the nation thanks to the persistent rainfall, cloud cover and onshore winds over the west of the nation as well. The north will see a reduction in the heat levels from as early as this weekend.

This product will be updated once again on Friday.