A trough and low pressure system is expected to link up with a cold front to bring showers and patchy rain to western and southern areas of the state during Saturday afternoon and evening. There is the risk of a few storms over parts of the southern inland now looking at the latest upper air data but they won't be widespread and conditional.
Sunday and Monday looks cool and cloudy with areas of rain through northern and eastern districts with the weather trending drier the further south and west you go.
Another system is expected to bring a burst of showers and storms mid week with areas of rain possible over the eastern half of the state once again where moisture is deeper.
Lets take a look
Rainfall for the next 10 days
No real change from the guidance this morning with moderate falls expected from this first system mainly over northern areas of the state, but now a southerly change moving up the coast could increase rainfall for southeast parts of the state during Sunday which may surprise. Another batch of rain and storms will form on Monday along this trough over the northeast. Yet another trough is expected to develop from SA during Wednesday or Thursday with more showers and storms, mainly across southern and central areas of the state. The weather likely remaining unsettled through to next weekend over the north and northeast.
Model Spread and Low Pressure
The track of the low pressure will have a huge impact on the rainfall distribution over the weekend and if the GFS track develops, this will impact the weather upstream in the Bight coming through mid to late week. So watch the forecasts closely.
Thunderstorm Forecast Friday
A pressure trough moving into western NSW coupled with a deeper moisture supply may see afternoon showers and thunderstorms develop over parts of the southern and central inland, extending up along the QLD border. Storms may be gusty at times with moderate falls and while there is the risk of large hail and heavy rainfall leading to flash flooding, I am determining the risks low at this time.
Hail Risk Saturday
The risk is low end and I am not expecting a high risk to be issued but some of the stronger storms IF they get up may produce some local hail, some of those stones could approach 3cm in the strongest storms in the southern Riverina.
Damaging Winds Risk Saturday
A broadly unstable airmass and strong upper level winds may be mixed down to the surface with thunderstorms during the afternoon and evening, especially on the leading edge of a cloud band moving east. Raised dust may occur in outback NSW and through to northeast SA.
Euro 00z - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days
The surface pressure pattern is dominated by high pressure at the moment but watch the developing trough tomorrow and the appearance of low pressure taking over as we go through the outlook period as with heat levels increasing and that means heat rises and destablises the atmosphere. This will be the theme as we track through the weeks and months ahead. Now the first trough is to pass through over the weekend into next week bringing areas of rainfall with thunderstorms about. Rainfall confidence is low and refer to all the charts as low confidence over the east. For the west a strong cold front is expected to sweep the region, the major impact will be well below average temperatures for much of next week. Out of that front a second system forms and the forward motion of this system approaching the east is much quicker tonight on all guidance so there is some chance it could be absorbed into the first feature enhancing the rainfall over NSW and QLD. Over the north the tropics are set to fire, more isolated over northern WA and Cape York. Another trough and inland rain and storms is being progged for next weekend spreading from the NT through SA but that also carries low confidence. It is spring time in Australia.
Euro 00z - Precipitable Water Anomalies - Next 10 Days
The guidance on moisture is unchanged nationally from this morning, the issue is the placement of systems that lifts this moisture into areas of rain and thunderstorms. The tropics are turning soupy and that moisture seeps south once again later next week into the following weekend. The west stays under relatively dry air for now, but a pulse of moisture may approach from the Indian Ocean and invigorate a west coast trough just outside of this period.
Euro 00z - Rainfall Accumulation - Next 10 Days
Rainfall confidence is low nationwide, away from the southwest of WA where one system is expected to bring light falls and then conditions dry out. So pay attention to forecasts and do not get caught up on the data tonight, we are likely to see some further adjustments due to timing issues with the secondary system plus once the trough intialises in real time and the low forms in real time, then guidance improves.
A closer look in
GFS 00z - Rainfall Accumulation - Next 10 Days
Refer to Video for more information
More weather information coming up later this evening with the model wrap and rainfall after 9pm