NSW - ALL EYES ON THE WEEKEND SYSTEM.

Settled weather for now with a high anchored over the region with a good supply of dry air and stable air at that. It is breezy over the south tonight and there is a few showers possible but really limited rainfall. Also the chance of a thundery shower over the far west this evening and early morning but light falls if anything comes of that.


The main weather action is sitting back through the weekend, that is courtesy of the inland trough that staggers back as the cold front races through tonight and tomorrow, it is likely to be picked up again and then propelled eastwards over the weekend by another cold front. Moisture ahead of the system likely to deepen further and widespread rain is expected to break out. But who gets what, it is changing from run to run.


Lets take a look

Rainfall next 10 days

Rainfall kicks off from the weekend over northwest and western parts of the state as a low approaches from the northwest. The heaviest falls are yet to be determined and once we get a low level centre identified, the models will struggle with rainfall forecasts. But from Saturday night through next week, expect scattered to numerous showers and storms, areas of rain with moderate falls. A follow up trough may also keep the rainfall chances elevated through the back half of next week before another break in the wet weather develops as high pressure approaches.

Euro 00z - Surface Pressure Pattern and Rainfall Distribution - Next 10 days

The weather pattern is very tricky to pin down so I will keep it short and sweet because the analysis is quite limited with diverging modelling. The weekend system is still being modelled poorly but if you are living through NSW, QLD and northern VIC through to northern SA and the southern NT, you have the better chance of seeing rainfall develop over the coming week. Who gets what remains to be seen and as appropriate rainfall forecasts carry low confidence straps for the eastern states. The west will see another burst of colder weather after a milder weekend with a strong cold front next week, that will send a cooler pulse of air through much of the SWLD and points further north and east. Meanwhile the weather over the north and east looks unsettled with periods of rain, scattered showers and storms in a humid airmass. The north getting more unsettled as we cruise into the wet season.

Euro 00z - Precipitable Water Anomalies - Next 10 days

The PW Anomalies paint the picture of the deep impulse of moisture from the tropical north being drawn south and fed into the trough and low pressure coming out of WA through the weekend. The moisture is likely to linger through interior parts of the nation while the west of the nation sits under mainly dry air. A stronger front will approach the SWLD of WA and send another strong pulse of drier colder air into the western half but may spread into western SA and stop there. The blocking pattern developing in the east lends itself to see moisture deepen through the eastern two thirds of the nation.

Euro 00z - Rainfall Accumulation - Next 10 days

Rainfall accumulation carries a very low confidence in the east even on the Euro and I will suggest that if you are relying on your yr.no sites and other apps, they are useless, your numbers will change and the forecasts for rainfall across the boards, all agencies, carries low confidence, that is a hallmark of spring forecasting. We won't get a better guide until Friday so watch this space. The nations rainfall guide is determined by the events and evolution of the low pressure system through the central and eastern states over the weekend, once that is decided then confidence grows.

A closer look in

GFS 00z - Rainfall Accumulation - Next 16 days

Check out the video for more.

I will have a look at all the models and the rainfall potential nationally after 9pm EDT





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