The weather is becoming unsettled on Saturday with a deep moisture feed moving from the NT into SA during Saturday, ahead of a trough and cold front, expected to meet this moisture sparking patchy rainfall over southern areas but more extensive rain and thunderstorm activity for northern and eastern districts.
Some areas over the northeast could see 1 months worth of rainfall over the course of the next 2 days as the system moves through, with locally heavy falls with thunderstorms.
The system is expected to move on by to the east with high pressure quickly coming in to clear the south and southeast.
Another system is expected to approach during Wednesday with a leading trough to bring a few showers and thunderstorms, once again more extensive over the eastern districts where moisture is deeper and the air more unstable.
Lets take a look.
Rainfall next 10 days
Rainfall is expected to be patchier over southern areas for the first system, with most falls less than 10mm for the event, up over the northeast, some locations could clear 30mm of rain with thunderstorms which would be above average rainfall for October. Another system will be approaching during Tuesday, this will clear the rain out of the northeast. By Wednesday, showers and thunderstorms are expected to return with a trough and low pressure system moving by. The deeper moisture looks to be over the east and into NSW and VIC where rainfall will be more extensive but another round of light to moderate rainfall is expected for southern and southeast areas. Further troughs exist beyond this period with moderate rainfall opportunities.
Thunderstorm Forecast Saturday
Thunderstorms are expected to develop from early in the day over the northern areas, mainly elevated with light and patchy rainfall initially. During the afternoon deeper convection is expected to form over the Flinders and Northeast Pastoral Districts which could generate gusty winds and small hail. Some moderate to heavy rainfall is possible from these storms. Raised dust is also possible.
Hail Risk Forecast Saturday
Just a small area identified at elevation over the Flinders region. This is a low end threat for now and cloud cover and lack of surface based instability could snuff the risks. The higher risk sits back in NSW.
Damaging Winds Risk Forecast Saturday
Damaging winds in excess of 100km/h possible with thunderstorms over the northeast during the afternoon and evening.
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