NSW - SHOWERS AND THUNDER SPREADING THROUGH FROM THE WEST OVERNIGHT.

A warm and relatively breezy day throughout the remainder of the state is shifting unsettled as we go through the coming 12-24hrs with a milder change shifting eastwards. Will it bring much rainfall? And what about the latest on the cold snap?


Lets take a look.

Rainfall for the next 10 days

As explained throughout the course of this week, main rainfall opportunity through this period is with the system rolling through overnight and into Saturday morning with a trough and moisture in feed, the main dynamics are falling apart for widespread rainfall and heavy falls at that. The weather is expected to turn sharply colder with a southwesterly change and another band of light rain Monday. The main impacts from rainfall will be over the southern inland and along the western slopes of the GDR. The weather remaining mostly dry through much of next week. The next chance of rainfall is sitting just outside of this period.

Farmers and Graziers - Monday through Wednesday

The main issue in coming days will be the impact of the cold weather passing through the south of the state, bringing a burst of high impact cold temperatures from stock stress to severe frost potential. This forecast will be adjusted during the weekend, and hopefully moderated down a level or two!! But be aware if you are on the land!!

Thunderstorm Forecast Saturday

Thunderstorms over the Lower and Upper Western this evening, will progress further east with the risk of damaging wind gusts and raised dust. Not much in the way of rainfall sadly with the lower levels dry as expected. The thunderstorms will move into marginally better moisture tomorrow and this could raise the chances of measurable rainfall the further east you are. Severe thunderstorms with damaging winds and moderate lightning activity possible over the northern inland extending to the coast during the afternoon and evening. Storms clearing east during the day.

Damaging Winds Risk

Strong gradient winds ahead of the front passing through the southeast tonight and tomorrow over Alpine areas. The risk of damaging winds over the northern inland and southern inland of QLD is expected with any high based thunderstorm that develops. This may mix down the strong upper level winds to the surface.

Raised dust risk - Saturday

There is a lot of dust about this afternoon through the Lower and Upper Western and this will continue tonight and into Saturday before the risk marches east with a clearing band of showers and storms and winds ease from the west. Reduced visibility and poor air quality likely under the current guide, especially nearer thunderstorm activity.

DATA

THE MODEL MADNESS FOR EARLY NEXT WEEK -

GFS 00Z Tuesday

A low develops on the front and moves slowly east, cutting off from the westerly flow.

Euro 00Z Tuesday Afternoon

The Euro moves the system through as an open wave with no low pressure near NSW, but forming it closer to NZ.

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

Pattern is largely unchanged but shows a colder airmass that poses some concern for the southeast states next week in terms of frost and graziers issues with well below average temperatures. The weather over in the west by contrast, lovely, settled and warm, and the hot dry weather over the tropics will continue right through the outlook. The weather over the eastern inland north of NSW will likely remain dry for much of the outlook. There may be a front that interrupts moisture building back up over northern and eastern areas of the nation in the last week of September, but not all models agree on this idea, and introduce a low pressure system from WA with inland troughs forming. With the SAM trending more positive, I would think easterly winds likely return, but not one rule in weather is ever fixed. But it is looking quieter next week past the cold blast.

Euro 00z Precipitable Water Anomalies - Next 10 days

PW Anomalies really paint the picture of the significant dry airmass developing throughout the nation, suppressing rainfall chances, drying out the tropics and combining with high pressure to promote clear skies and increasing the risk of frost through the eastern states. How severe the frost gets remains to be seen, but will keep watch and have frost forecasts for the east next week by Sunday. Otherwise, the moisture does return over WA later next week into the weekend and this may start to introduce rainfall back for the last week of the month. Otherwise it is benign for now and quieter next week.

Euro 00z Rainfall Accumulation - Next 10 days

No low and I am siding with this solution for the region at this time but as always you have got to watch closely.

GFS 00z Rainfall Accumulation - Next 16 days - A second system is on the board later in September which Euro does not see that far out.

More details to come on Saturday morning with the National Weather Wrap and if there are any developments surrounding the low pressure system forming over NSW I will have an update immediately on that. That appears to be the focus of weather nationwide this week.


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