LONG TERM OUTLOOK - 6 WEEKS - CAN WE GET A HARVEST GOING IN THE EAST!?

Very tough times for those in QLD and NSW with high humidity and excessive rainfall continuing to cause many operations to grind to a long halt. Produce such as cherries have copped an absolute belting and coupled with a lack of pickers, lots of good fruit getting smashed. Stone fruiters and struggling with the high humidity and wet weather and we have some wheat crops that have just had about enough rain for one year!


SA has faired reasonably well with the rain lifting out of Ag Areas earlier with the low moving further north and just enough rainfall to be not too annoying.


WA things are hot and dry.


Can we see conditions ease in the coming weeks over the east or is the flood weather about to take it up a notch?


FORECAST

Rainfall Outlook Next 6 Weeks - November 26th 2021 - January 9th 2022

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

The wetter as you go through Australia continues in line with the waning negative IOD phase, the deepening La Nina phase and the persistent positive SAM signal. The wet weather ramping up this weekend and really not taking a break for parts of eastern QLD and NSW over the coming fortnight. For the tropics the rainfall is expected to rapidly increase after a very hot week. The heat that has been in place over the north of the nation helping to draw in the tropical weather to the north. The wet signal does extend to most all of the nation but it is a lower risk over the southern and southwest, but even there, wet weather is expected. Flooding and severe flooding is possible in many areas during this period if the data verifies. Rainfall is conditional over WA and dependent upon the movement of tropical moisture to the north and placement of troughs and low pressure systems which is common for this time of year for this region.

Temperature Outlook Next 6 Weeks - November 26th 2021 - January 9th 2022

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

Seeing a shift in the climate guidance from the well below values to near seasonal to warmer values returning to WA and SA as well as central interior parts. This may spread further east into VIC and NSW as well as QLD at times. But as seen last week with the high heat, it leads to heavy rainfall at this time of year over in the east, so the hotter weather is a double edged sword.

Humidity Outlook Next 6 Weeks - November 26th 2021 - January 9th 2022

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

I was hoping the signal would shift but looking at the rainfall data and extended PW values into January, the risk of higher humidity remains maxed out over the east, central and northern parts of the state with the west seeing drier weather at times, but even there, moisture will increase as the monsoon returns. That will lead to above average humidity values over northern Australia which we have seen of late with DPs into the low 30s.

Disease Outlook - November 26th 2021 - January 9th 2022

The wet weather, and now a shift to warmer weather with high humidity increases the risk of fungal diseases to many crops. This signal does not change over the coming 6 weeks. The west may be dry for now, but there will be an increase in humidity returning through this period and with the higher temperatures this could see prolonged periods of above average humidity values.

Riverine and Flash Flood Risk December 2021

The fact we have ongoing flooding for much of December as a lag from November, additional rainfall will continue to exacerbate this risk through until early 2022. Many inland rivers could be flooded right through Summer 2022. The risk will return for outback areas once the monsoon starts so the back half of the month, areas away from the east need to pay attention to trends in the medium term forecast.

Riverine Flood Risk Summer 2021/22

The flood risk is ongoing and continues through December and January. Keep up to date with the medium term forecasts in the east as rainfall could return next week and persist again.. The weather should turn wetter over the inland of WA as tropical weather increases with that starting from the second week of December as per some of the guidance. The monsoon should start to have an impact on rainfall for the north from mid December at this stage.

CLIMATE DASHBOARD

What a significant week of rainfall across the nation, all thanks to the three drivers working together to promote these large scale rain events. The IOD is waning still, but the influence appears to continue for another 2 weeks. I was anticipating the influence to wane by now but there is still more moisture being drawn in until mid December and an early monsoon could provide a decent amount of moisture as well. The ENSO is the driver that is taking over, with a La Nina phase underway and strengthening in the next 4-6 weeks, likely to peak in January before waning through February. The SSTs in the Coral Sea suggest that the La Nina has been underway for some time, thankfully we have now seen all global agencies including the WMO calling it a La Nina. The SAM remaining positive into early December with brief stint back to neutral values at times, but generally positive of normal is likely.

TROPICAL WEATHER

The MJO has passed through to our north in the past week and is now indiscernable with no impact expected over the Maritime Continent. With a La Nina developing and the waning negative IOD phase, the enhanced moisture, build up conditions will persist and the the likelihood of an early monsoon is gaining momentum as the MJO phase may redevelop by mid December which could assist in enhancing rainfall over the tropical north. There are some signals that it could favour QLD and the Coral Sea.

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


RAINFALL

Euro Rainfall Accumulation Ensemble Data - Next 6 Weeks - November 26th 2021 - January 9th 2022

The majority of members increasing the rainfall signal over the east with no change in that guide, it is only getting wetter and more broadly wet. The northern tropics, active and well ahead of schedule which I am siding with during this period. That will mean elevated moisture levels passing through the nation and that means further widespread rainfall chances.

Euro Rainfall Accumulation Control Data - Next 6 Weeks - November 26th 2021 - January 9th 2022

Exceptional rainfall totals in the southeast and east, with inland flooding continuing to increase in chance over VIC, NSW and QLD. The tropical weather also well above normal in terms of coverage and I am leaning with that solution. The Euro again showing that tropical moisture sweeping into WA is a representation of the monsoon arriving through this time and that will provide above average rainfall chances for the remainder of northern Australia. The east, you think it is wet now, just wait for the coming 6 weeks!

Euro Rainfall Anomalies - Next 6 Weeks - November 26th 2021 - January 9th 2022

The numbers continue to increase above the average for this period as we end the year and kick off 2022. Many areas over the east have observed record November rainfall and having this rainfall presentation suggests a lot of wet weather to come. The northern tropics looking wet but ignore the brown and red shading next to the bright blue. The overall signal is wet for the north and northwest. There is a strong chance of a strong monsoonal flow developing over the Coral Sea during this period, which may increase early cyclone activity for eastern Australia.

The Euro Control Anomalies for the coming 6 weeks - this has major flooding written all over it, but is now starting to show that QLD may be in the firing line for the worst of it and a maintaining for flooding for NSW and VIC.

CFS Rainfall Accumulation Control Data- Next 6 Weeks - November 26th 2021 - January 9th 2022

The very wet signal continues on the deterministic data set, this model does not pick the tropical weather well at all, and if you use a little bit of logic, if this is showing the rainfall as is across the nation without the early onset rainfall signal, there is every chance that it may be UNDERDOING rainfall totals over the east in particular which is cause for concern. The tropical rainfall is well understated here. Mixed odds in rainfall distribution elsewhere is a product of summer time weather and that is very hard to pick well ahead of time. The higher confidence in the forecast is found over the east.

GFS Rainfall Accumulation - Next 5 Weeks - November 26th - December 29th 2021

Significant rainfall signals continue for eastern Australia and tropical rainfall expected to increase over the coming weeks, we have seen daily totals clear 100mm in recent days. The modelling is drier over the north and west but it is an outlier on this idea. The east is where the forecast confidence remains high and based off recent updates, this is continuing to INCREASE in number for this region which if it verifies is remarkable.

GFS Rainfall Anomalies - Next 5 Weeks - November 26th - December 29th 2021

The model is now showing a dry bias over the northern and western parts of the nation with the monsoon being analysed over the Pacific Ocean. That remains very low confidence. The high confidence is over the east and southeast of the nation where the rainfall is expected to remain well above normal.

CMC Rainfall Accumulation - Next 4 Weeks - November 26th - December 22nd 2021

Additional rainfall to come over northern and eastern Australia is excessive and this is a concern once again for those looking for drier weather. Numbers will remain near to above average for the coming period over much of SA and through pockets of SA with the tropics tending more active and a monsoonal phase approaching from the north.

CMC Rainfall Anomalies - Next 4 Weeks - November 26th - December 22nd 2021

The excessive wet phase is expected to continue as we run into Christmas, this has not changed since this updated last week, and what is more concerning is the fact this is additional rainfall anomalies above what has fallen over the east.. Blue shadings in a time when the north is wet spells trouble for further flooding rainfall across the nation and cooler weather. I would ignore that drier signal inland of Darwin as that is conditional. This is only the next 4 weeks which shows you how wet the phase is.

TEMPERATURES

Euro Temperature Anomalies - Next 5 Weeks - November 26th- January 10th 2021

The east is looking very much below average with a decent supply of rainfall, cloud cover and this will suppress temperatures. The moisture may return frequently (after this drier period) to bring cloud cover through southern WA and into SA and then the southeast. Certainly are seeing that right now. The tropics seasonal and the west coast is above normal.

GFS Temperature Anomalies - Next 5 Weeks - November 26th- December 29th 2021

It is persisting with the warmer signal for northern Australia which is interesting, as the other models have been running cooler and the tropics indeed have been running hotter through this season, so certainly merit to this forecast.

SUMMER REVIEW

December 2021 - Rainfall Anomalies

This is not the greatest climate model but it does OK in picking trends. For the record it always shows the tropics from run to run in either bright blue or deep red. The constant theme this model has been showing is the wet signal over the east and tropical moisture spreading south through WA.

January 2022 - Rainfall Anomalies

The wet bias continues through the southeast and east and over the west coast and drier over the tropics. Again I do not buy that, the take away is the signal of that wet weather over the southeast and along the west coast.

February 2022 - Rainfall Anomalies

The wet signal increases over the tropics (will be wet throughout the wet season with La Nina) and note the tropical mischief being analysed through February off WA. The wet signal continues for the southeast and east coast.

SEASONAL

Summer - Rainfall Anomalies

But looking at the Euro, you can see this is seeing the La Nina involved and I suspect that the next update due next week will increase rainfall for the season as the climate drivers trend wetter.

I will have a look at December on Sunday in greater detail and next week I will have a Summer and Autumn Outlook plus a preview of Winter 2022.


There is a lot of weather going on now but I am already forecasting deep into 2022. The question people want answered is that is there going to be an El Nino next year? I will answer it next week.




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