MEDIUM TERM FORECAST - STORMY WEATHER CONTINUING FOR THE EAST WHILE THE WEST AND CENTRAL AREAS BAKE

The cruelty of stagnant pressure patterns are that those who don't want rain, get a lot and those who want some rain, don't get any. That pattern is set to continue for the next week with the storms persisting over the east and north with high humidity. That means where it rains, it will pour even in the absence of a major weather event like we have right now. Some areas could get 50mm from a thunderstorm in NSW and QLD so be aware of that.


For the west, those same easterly winds that are pumping in moisture throughout the nation is set to dry out as they run over land, bringing above average temperatures.


Lets take a look

FORECAST

Moisture Watch Next Week - December 3-10 2021

Moisture will creep southwards through WA from the tropics and there may be an injection of moisture from the northwest at the end of the period, otherwise it is dry for a while out there. It is a similar picture for southern SA with the moisture over the NT are passing southwards during this period. Where you will find the deeper moisture profile is over northern and eastern Australia with the persistent easterly winds and the positive SAM in place.

Rainfall Next Week - December 3-10 2021

Rainfall is largely unchanged from yesterday, there is that major rainfall event that is being hinted at by the models at around the 5th of December onwards for QLD and NSW once again. That will be an item to watch next week. For the north, the heavy rainfall with storms will continue, with above average precipitation rates continuing thanks to the deeper moisture. Some moisture will return over the west and south through this period with isolated showers and thunderstorms about.

Rainfall Anomalies - November 26- December 10 2021

The rainfall anomalies remain off the charts above normal for the east with this current rainfall event with evidence of not only the storm outbreak over northern and eastern areas next week and another rain event coming into play from the 5/6th of December out east. We need to watch that closely. Otherwise seasonal to leaning below seasonal for the SWLD of WA.

Temperature Anomalies Next Week - December 3-10 2021

A nice warmup is coming for southern Australia next week from WA, the warmer weather will struggle to move further east onto the east coast with the persistent easterly winds modifying the airmass. The northern tropics should begin to feel a reduction in temperatures.

DATA - Refer to the video for more information


18Z GFS Surface Pressure Pattern and Rainfall Distribution - Next 16 Days

Keep a very close eye on the potential for the SAM to strengthen the wet signal in the first week of December through to the 10th of December over QLD and NSW which carries some concern. Otherwise fairly quiet for the remainder with seasonal weather expected.

18z GFS Precipitable Water Anomalies - Next 16 Days

The battle between the dry air to the south and the humid air to the north plays out over the course of the next fortnight. If the high moves further south through the outlook, the further south the moisture will travel and the higher the chances of rainfall will be for southern areas of the nation. At this stage there is some model conjecture around this, hence why the rainfall moves around a lot. No doubt, the wet weather continues for QLD and NSW.

18z GFS Rainfall Accumulation - Next 16 days

The moisture is increasing nationally in the medium term yet again as you can see above, and the low pressure will begin to dominate the outlook period as the high pressure belt to the south moves further south and the easterly flow begins to deepen and fresh, bringing in large amounts of moisture into those low pressure troughs.

The tropics responding to the deeper easterly flow and the approach of the troughs sitting offshore the north coast.

This is additional rainfall to what is falling right now. Note the rainfall bias over the coastal areas with the onshore winds and the trough over the inland not going anywhere, feeding off the moisture surging in from the northeast and easterly flow.

12z Euro Control Rainfall Accumulation - Next 15 days

Note that heavy rainfall over the east coast in response to the positive SAM in the medium term beyond this rain event.

12z CMC Rainfall Accumulation - Next 15 days

The moisture creep is on from the north through the nation and yet again, this model has picked the last 4 events ahead of the other models.

There will be no video this evening as I am travelling so the next update will be Saturday morning. Have a good Friday afternoon and stay weather aware over the east and stay across flood warnings.



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