The unsettled weather is moving from SA into VIC and NSW tonight with the lead band of rainfall moving into Central areas and scattered showers and thunderstorms over the Great Dividing Range from southern NSW to southern QLD producing heavy rainfall in scattered locations this evening.
A strong batch of thunderstorms is likely to emerge on the trough as it progresses further east through NSW and VIC with gusty winds and heavy rainfall before that activity weakens tonight.
Sunday is looking unsettled over the northern and eastern inland of the nation but the focus of severe will be reserved for NSW and down to the ACT with heavy rainfall and damaging winds a risk. That heavy rainfall risk also skirts through southern QLD. Storms continue for the outback as well with more moisture pooling ahead of the next trough deepening in WA.
That system over in WA is the feature to watch, it has had many different looks to it on all the modelling. The latest guidance wants to bring the severe weather risks mainly through NSW and QLD but other models still hold heavy rainfall and strong winds for parts of SA and parts of northern and eastern VIC. So all areas from SA through to the eastern states need to watch this system.
Lets take a look
Rainfall Next 10 Days
The rainfall bias is sitting over northern and eastern Australia, that is where you will find the heaviest rainfall throughout this outlook period and the highest humidity and instability. That is leading to the severe weather risks during this outlook period. So if you are living through QLD, NSW, VIC and portions of northern SA and southern NT, pay attention to the forecasts this week. The rainfall will increase from the west, with a deep low expected to form along a trough from Tuesday. Another small scale low may develop over the southeast states, but some divergence in guidance remains on that feature. This is what makes the forecasting very tricky, as that system may deflect the highest humidity and rainfall potential through the northern parts of SA into QLD and northern NSW, leaving a drier airmass and cooler stable air into southern states. But if the system moves off quickly, then the low from WA will move further south pulling in the deeper moisture across the nation's east and southeast with heavy rainfall and flooding possible. Severe thunderstorms also to feature regularly between now and that system moving through. So overall it is a nasty looking week of weather for those on the land. The tropics where the moisture is surging south from looking to remain active throughout the period.
Thunderstorm Forecast Sunday
Thunderstorms may be ongoing from previous activity that flares up on Saturday over western NSW and QLD. These likely to be non severe and elevated. More storms likely to form during the afternoon and evening, mainly on and east of a trough that will be moving eastwards. Strong to severe storms are possible from near Canberra up to Cunnamulla and northwest to north of Birdsville. Severe thunderstorms possible with heavy rainfall and damaging winds over the inland Top End. Storms increasing over eastern WA with a developing trough.
Thunderstorm Forecast Monday
Severe thunderstorms are possible in a broad band along a trough with strong and gusty winds the main risk. Heavy rainfall leading to flash flooding may be a risk through QLD into northern NSW with high moisture levels continuing. The storms may increase over WA with heavy rainfall and gusty winds during the afternoon and evening near a developing trough and low.
Thunderstorm Forecast Tuesday
Severe thunderstorms continues to be a widespread risk through QLD on Tuesday with heavy rainfall and damaging winds the main risk. An upper level trough approaching the NT and northern SA from WA will spark severe thunderstorms with the chance of damaging winds, large hail and heavy rainfall leading to flash flooding. The storms may begin to lift out of WA as the low and trough moves eastwards. The storms over the Top End may be gusty at times.
Thunderstorm Forecast Wednesday
Thunderstorms may turn severe to dangerous with high levels of moisture leading to high end flash flooding through parts of inland QLD, and after repeated thunderstorms throughout the outback, the run off could be quite severe. Damaging winds and large hail also possible ahead of the deep trough emerging from SA. Severe thunderstorms possible through the NT with damaging downbursts. The storm focus is contracting east through the nation with the trough moving out of SA by Thursday.
DATA - More information in the video above.
00Z GFS - Surface Pressure Pattern and Rainfall Distribution -Next 16 Days
I don't think we will see that clean out and southwest flow this time next week, I am leaning towards the easterly winds continuing and more moisture lingering throughout the nation through the medium term. I will also mention, watch the system over the southeast Tuesday, as that could produce high end severe weather ahead of the major low Thursday and Friday in the east.
00Z GFS - Precipitable Water Values - Next 16 Days
The PW values are still off the charts, but I would no be buying that drier air surging through just yet in 7 days. I have seen many different looks suggesting the weather trending unsettled and humid for large parts of eastern and northern Australia. Some of the values here are near 70mm in QLD!
00Z GFS - Precipitable Water Anomalies - Next 16 Days
Watch the weather over the north and west of the nation too with some suggestion the Indian Ocean continues to seed the jet stream lifting the rainfall chances over the outback and into the eastern inland again beyond the weather madness this week.
00Z GFS - Rainfall Accumulation - Next 16 Days
Refer to video for more details.
More details coming up after 9pm tonight on all things modelling and rainfall potential, again the risk of flash and riverine flooding is set to increase. We have seen warnings issued for minor flooding in VIC, NSW and QLD in recent days.