CLIMATE - ROUNDING OUT 2021 AND LOOKING INTO JANUARY 2022.

The data coming in this morning is largely unchanged and I have scoured through the sets and as I know many are very busy, I will just post a shorter version this morning and more details can be found in the video.


We may be dodging a bullet this December in terms of more flooding rainfall with the monsoonal flow bypassing the north of the nation leading to less moisture being propelled south and east from the tropics. Fingers crossed, as this will lead to a drier and hotter spell for the nation and a chance to dry out some of these catchments while the La Nina strengthens. The wet weather will be back in full force in the New Year and while I am forecasting a very wet start to 2022, I am hoping that it is wrong and we see less flooding potential.


For the west of the nation, the Summer heat has finally arrived and that heat will spread through the nation next week, with some areas expecting to see a very warm week before the weather returns to being humid and unsettled.


Looking further ahead, Christmas looks humid and unsettled for the east and of course over the north, but we may be minus the monsoon which would see less rainfall over the north and east. This pattern will persist through to the end of 2021. WA and SA looking mostly dry through to the end of 2021.


Most of January looks wet and stormy for the east and north and there is likely to be a more generous monsoonal burst through this period going off the climate guide. The west looks hot and mostly dry with that weather pushing into SA, so seasonal weather for these areas.


Lets take a look

FORECAST

Rainfall Outlook Next 6 Weeks - Next 6 Weeks - December 3rd - January 17th 2022

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

The signals from the north not as robust for heavier moisture and rainfall passing through from northwest to south and southeast which is good news for eastern inland areas. However the positive SAM phase may mean that rainfall will be elevated throughout this period regardless of the tropical influence so we must watch this signal closely. The west of the nation looking relatively dry but there are signals of moisture returning with mixed odds for showers and thunderstorms throughout this period, but relatively seasonal conditions for now. SA and VIC should also see mixed odds in terms of rainfall but the further west you go through both states, the drier you will be. The tropical north may start to see elevated rainfall throughout January with a monsoonal burst pushing through nation's north, and through this period is where you find the wild card systems being the tropical lows/cyclones that these models do not pick up.

Temperature Outlook Next 6 Weeks - Next 6 Weeks - December 3rd - January 17th 2022

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

Cooler signal persists for the east and the southeast as we see more clouds and rainfall developing through the outlook period. The west and south of the nation may trend a bit warmer in the short to medium term, but temperatures could come down with persistent troughing over the north and through the west of the nation leading to more clouds and rainfall returning. The tropical moisture and rainfall distribution will be key to observed temperatures through this period. Most of the nation should see seasonal values overall with the cooler bias over the east and the warmer bias still out west despite the cooler signal appearing in the latest data sets. Will review this again on Friday.

Riverine and Flash Flood Risk December 2021

Still have elevated risks of flooding throughout this period with deep moisture pooling over northern and eastern Australia and the positive SAM leading to more rainfall in the short term. There may be a lull in the middle of the month but the rainfall should return in full force during the end of the month into January.

Riverine and Flash Flood Risk January 2022

The monsoonal weather over the north and east will fire off the next chance of heavy rainfall and flooding potential for northern and eastern Australia and you can see that evolution in the video with rainfall rates increasing as we go through early 2022. The weather will continue to become wetter for southern and southeast parts of the nation with the catchments remaining quite saturated through southeast areas of NSW and the ACT.

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

The wet climate drivers are still in play, and to cut through all the content this is what you need to know. The IOD is now complete and back to neutral values with little influence, but the negative influence may persist in the atmosphere for another 2 weeks. I think the trend for the MJO influence is now passing by the north of the nation and we are looking the monsoon passing into the Coral Sea through mid to late December, at this stage. The ENSO is the driver has taken 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 SAM remaining positive for the coming week, then neutral through mid month before returning to positive territory for the remainder of 2021 and into early 2022.

TROPICAL WEATHER

The MJO is forecast to strengthen just to the east of the nation in the Pacific through the mid to latter parts of December with heavy monsoonal weather likely to emerge in the wake of a tropical low that will form out there. If this occurs, then reduced rainfall over northern Australia is likely and prolonged build up conditions. This is not a sign of a failed wet season, just a placement issue with the monsoonal flow bypassing northern Australia and there will be multiple attempts to bring the monsoonal flow south through Australia into January and February which are usually most active and productive n the wet season.

The monsoonal flow is expected to run north of the nation and pop into the Pacific mid to late month at this stage, but the modelling can quickly snap back the other way so stay up to date. This would be reduced rainfall for the north and east. The yellow is light monsoonal flow, the red the stronger monsoonal flow.

For all the weather weenies who want to see all the data sets and more analysis, check out the video.


This will be updated during Friday morning.





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