Well we are here ready to harvest and underway with operations and the guidance has always been wetter as we go through Spring and more unsettled as we get warmer. We have seen that script play out, now we watch, sadly, the rainfall step up a notch in the short and medium term, but also likely to peak later this month and through to Christmas for many of you guys over inland Australia.
Coastal farmers in the south have already experienced the higher humidity and the rainfall and thunderstorm activity, this frequency looks likely to remain above average, but you will get more breaks than your eastern coastal and inland friends with the high humidity expected to remain above average for long duration leading to more rainfall and disease risk.
Farmers out west basking in a cooler and wetter Spring see not much change for the remainder of the season. Your Summer may also start out cooler with more humidity floating in from the east and north thanks to the tropics, raging along with near record humidity values and rainfall observations over central interior parts.
And finally for tropical friends we will be talking more about the MJO moving through the future forecasts from next week now we are seeing the tropics tending active and monsoon is slipping south of the equator soon.
Lets take a look
Rainfall Outlook Next 6 Weeks - November 5th 2021 - December 21st 2021
% chance of exceeding the median rainfall for the coming 6 weeks
No change from the previous update earlier this week. Now we are starting to experience the rainy, humid shift over large areas, heavy rainfall with thunderstorms, flash flooding etc. This is not going away. This is what we are going to be dealing with for the eastern 2/3rds of the country, and again the rule of thumb, the wetter and more humid the further east you go throughout the nation. However, as long as the central interior of the nation remains wetter than normal will continue to mean the southeast and east of the nation remains, humid, wetter than normal with the high risk of disease and weather impacts to your crops. In the short term that is likely to be the focus for many of you out there, managing the risks are just sitting back and hoping that conditions do not turn out to be as wet and unsettled as advertised. For QLD, NSW and VIC, keep watch on the severe weather outbreaks in the medium to longer term, the longer term modelling continuing the higher amplitude pattern. For SA, you are likely to see systems form over the region, passing in from WA and then linking up with moisture from Central Australia allowing for showers and thunderstorms breaking out before hosing down the east. Severe weather impacts and high humidity continues to be a moderate to high risk for the region. For WA, above average rainfall coming in fits and bursts will continue given the moisture rotating through the inland ahead of deepening heat troughs. The tropics will continue to lift rainfall chances throughout this period.
Temperature Outlook Next 6 Weeks - November 5th -December 21st 2021
% chance of exceeding the median temperatures for the coming 6 weeks
We are now seeing the impacts of the higher humidity and increased cloud cover capping day time temperatures over the eastern inland of NSW and into VIC, not cold, but humid and cool. This is the weather you can expect to see across inland SA and VIC and most of NSW and western and central inland QLD as we go through this period. The risk of above average temperatures and heatwaves, very low leading into Christmas. The tropical north should also see a reduction in temperatures thanks to enhanced rainfall and cloud cover.
Humidity Outlook Next 6 Weeks - November 5th -December 21st 2021
% chance of exceeding the median humidity for the coming 6 weeks
Higher humidity values against the average continues to be observed throughout the north and has now shifted into the southeast and east of the nation with the stationary troughs and low pressure lifting this into showers, rain and thunderstorms. The higher moisture content into the medium term 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 is now high. 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 5th- December 21st 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. All farming operations are likely across the weather situation and should be on alert over the coming 6 weeks.
Severe Thunderstorm Risks to Farming Next 6 Weeks - November 5th- December 21st 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. In the medium term we have 2 events that could bring nasty severe weather issues to the nation's east and southeast. 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.
Riverine Flood Risk - Next 6 Weeks - November 5th - December 21st 2021
As mentioned last night, this zone remains under a very high risk of flood issues and I will update this chart again next week to include more of QLD and the outback of SA through the NT. But for now this is a huge area of concern through harvest.
Flash Flood Risk - Next 6 Weeks - November 5th - December 21st 2021
We have already observed flash flooding from many outback communities this week from the NT, through northern SA into western QLD and northwest NSW and northern VIC. The risk of flash flooding remains elevated on the current guidance from modelling this morning. Remain weather aware and stay up to date with the short and medium term forecasts in particular through to mid November if you are living in the eastern 2/3rd of the nation.
Large Hail Risk November 2021 - New South Wales and Victoria
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. The medium term offers a heightened hail risk through to about the 21st of November.
The risk should start to reduce from December, and looking in the medium term, the risk may be peaking during the period from the 8th-21st of November through southern and eastern areas.
All it takes is one storm to cause significant damage - as we saw through the Barossa last week. So you may be sitting in a less frequent rainfall/storm region in SA, but you are residing in a zone where the dry air is wrapping into the moisture and that could see hail risks be increased in future forecasts coming up next week.
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. This will be updated on Tuesday.
DATA - Refer to video for more on these sets of data
Euro Rainfall Accumulation Ensemble Data - Next 6 Weeks - November 5th -December 21st 2021
A wet and unsettled run of weather is anticipated for the run through harvest into Christmas. All Agricultural regions in the nation will be dealing with elevated humidity, above average rainfall chances and disease risks through this time. I cannot be anymore specific than that, because the risk is so broad. Your rainfall total will vary from place to place given thunderstorms are involved and we have already seen that this week. The further north and east you go through the nation the wetter you will likely be. Flooding is a significant risk for VIC, NSW and QLD plus areas of the outback.
Euro Rainfall Accumulation Control Data - Next 6 Weeks - November 5th - December 21st 2021
Singificant rainfall of 500-600mm is possible over parts of the NT and this exceptional rainfall forecast from the data sets will mean rainfall further south and east will be equally wet, well above average with some areas seeing rainfall records set. Now you can see that dry area over SA, that does NOT mean SA will be dry, that means there will be pockets that miss out on the flash flooding and heavy rainfall through this period. It could be western NSW, it could be northern VIC, it could be southern WA. This overall is a wet forecast for Ag areas across the nation.
Euro Rainfall Anomalies - Next 6 Weeks - November 5th -December 21st 2021
Exceptional rainfall anomalies above normal continues across vast areas of Australia. This would lead to flood risks increasing through the coming 6 week period leading into Christmas time. The northern tropics drive the wet weather signal for much of the nation and there will be little breaks in the humidity for the northern half of the nation. The south can expect to feel a humid and wet remainder of Spring and start to Summer.
CFS Rainfall Accumulation Ensemble Data- Next 6 Weeks - November 5th -December 21st 2021
The wet signal continues for much the nation, but I want you to recognise the rainfall signal over interior parts increasing, in addition to what has already been observed. The rainfall could lead to flooding in some parts of the east and southeast and possibly the outback.
CFS Rainfall Accumulation Control Data- Next 6 Weeks - November 5th -December 21st 2021
Heavy and extensive rainfall being forecast for parts of eastern and central Australia but as mentioned in multiple updates the tropical modelling is a weak point in this particular model and something that we need to factor into forecasting. That could mean rainfall totals further south and east may be understated.
GFS Rainfall Accumulation - Next 5 Weeks - November 5th - December 8th 2021
The rainfall totals in the coming 5 weeks are exceptional off the 30 member data set, this is the control member, which also highlights the nature of the rainfall favouring the north, central interior and the eastern states. Even numbers through SA are quite high and may lead to record rainfall totals being observed north of the Goyder's Line. The numbers of the SWLD also above average for this time of year.
GFS Rainfall Anomalies - Next 5 Weeks - November 5th - December 8th 2021
The GFS is now moving into line with the other modelling, highlighting the southeast, the central interior and northern and eastern parts of Australia as the areas to record above average rainfall. But with the excessive moisture content we are experiencing right now through large parts of the nation leading to heavy rainfall totals, this chart may be underdoing the anomalies in some areas so just be weather aware and understand that some areas could see 1-2 months of rainfall from a thunderstorm.
CMC Rainfall Accumulation - Next 4 Weeks - November 5th -December 6th 2021
Rainfall totals in the brown of 100-200mm over eastern areas of QLD through NSW and into VIC is exceptional for a 4 week period, however I will point out that some of the members, triple the rainfall shown here, some of the other modelling is drier in these areas, but the signal is wet for the eastern two thirds of the nation and wetter the further north and east you go. The SWLD of WA starting to see numbers pick up and over the NW of Australia, numbers are also picking up. The tropics, well above average rainfall.
CMC Rainfall Anomalies - Next 4 Weeks - November 5th - December
Highly anomalous rainfall over northern and eastern parts of the nation over the course of the next 4 weeks off this particular product may break records over northern and eastern Australia. These values eclipse last years signal for northern and eastern inland areas lead into the first La Nina phase so this could set up a high risk of flooding for many areas heading into December and Summer in general.
Euro Temperature Anomalies - Next 6 Weeks - November 5th - December 21st 2021
No change in the guidance and again it has been well documented, below average temperatures emerging in line with the humidity and cloud increasing with rain also becoming extensive. It is basic science, less sun, less heat. Nothing more needs to be said.
GFS Temperature Anomalies - Next 5 Weeks - November 5th- December 8th 2021
The GFS has moved into line with it's sister model CMC showing a cooler bias now across the nation. You may remember from last week that this model was showing warmer weather for much of the north and east and now it is moving away from that, recognising the rainfall will be more abundant.
CMC Temperature Anomalies - Next 6 Weeks - November 5th- December 6th 2021
A cooler signal continues under the wetter weather, thick cloud cover and copious amounts of moisture available. This has been a strong signal from this model and continues to lead the way in predicting the wet weather and cooler weather.
More details to come on this during Sunday so again stay up to date with the short and medium term forecasting right through this month, I will endeavor to update daily as many of you are in your busy period, sweating on the rainfall, humidity, severe weather risks and the like over much of the nation. Weekend posts will be a little more broad but more detailed posts due out Sunday afternoon.