The weather continues to shift this today with a significant atmosphere change over the eastern parts of the nation continuing, moisture drawing in via the easterly winds. A trough deepening over the east will kick off showers and thunderstorms through the eastern inland which would be the first trough of the season.
Out west, a trough is expected to move into SA and then into the southeast states on Tuesday, merging with the trough and moisture over the east to produce widespread rainfall for the remainder of the week with a flood risk for parts of NSW and VIC at this stage.
Lets take a look
Rainfall for the next 10 days
Rainfall has remained unchanged from overnight with the heaviest of the falls expected to occur over VIC and NSW with the troughs merging across the eastern parts of the nation. The rainfall is expected to ease back during the weekend as the system moves on by. For the WA and SA, there will be patchier rainfall about this week, the best of it falling over the west, but during the latter part of the week, another system will likely work through with further rainfall. That system is tricky to pin down at this time and will be dictated by what happens with the first system over the east and whether it blocks it. The northern parts, wettest weather over southern and central QLD with storms increasing later this week. The tropics, showers becoming more widespread this week as the upper atmosphere cools and supports more rainfall developing.
Thunderstorm Forecast Monday
Scattered showers and isolated thunderstorms are expected through inland QLD this afternoon with a trough deepening. Some of the thunderstorms could be gusty with moderate rainfall totals. Some of the thunderstorms could creep into NSW later today. A few isolated thunderstorms possible over the far NT coast and Tiwi Islands.
Thunderstorms are possible once again in a broadly unstable airmass over SWLD of WA today and over the far east into western SA with a weak trough passing by. Storms unlikely to be severe. Moderate rainfall and small hail with gusty winds over the SWLD is possible.
Flood Risk Wednesday-Friday
Again if you live in these green zones, a heads up for minor riverine flooding this week. Some areas are expected to exceed 50-100mm in the green zones, especially with thunderstorms. So even if you get 20-30mm and miss the heaviest rainfall, there will be falls in the catchment which could double yours with storms in the region. Flash flooding is also possible.
Euro 12z - Surface Pressure Pattern and Rainfall Distribution - Next 10 days
The pattern is rather settled on the idea of the low pressure system coming through the Bight today bringing a trough on it's eastern flank over SA in dry fashion (hence why you see high and middle level cloud). Another trough will develop over QLD today with a few showers and storms. The systems begin to merge over the south and east of the nation and in good agreement across all models, the rainfall sits about VIC, NSW and QLD for much of this week into the weekend. Another system over WA brings a fairly decent burst of rain mid to late this week with that system expected to drift towards the east over this coming weekend. But it will come down to whether the lead system over the east blocks the passage of this follow up rainfall and forces the system south of SA, or the lead system moves through more efficiently and allows more widespread rainfall coming through the southern and eastern states this weekend. That will need to be watched. Over the north, hot and humid with limited shower activity until the weekend when the coverage increases with build up conditions increasing.
Euro 12z - Precipitable Water Anomalies - Next 10 days This again paints the picture of how the rainfall events evolve this week, with higher the average moisture content across the nations east and south. You will note the blue shading which shows values of 200% which suggests that the rainfall where it falls will be moderate to heavy at times. If storms develop they will be efficient rainfall producers. Note the follow up systems tapping into residual moisture across the nation which keeps the rainfall chances beyond this week relatively high over the continent. It will come down to the evolution of each system over the nation. A good example of this will be how the lead system coming through this week will impact the movement of the system over WA later this week, does it move east, or does it dive south and take all the moisture with it offshore?
Euro 12z - Rainfall Accumulation - Next 10 days
No real change from last night. You can see the GFS underneath and refer to the video for more details.
GFS 12z - Rainfall - Next 10 days
I will have more on this rain event, severe weather threat, a look at the medium term and if I can fit it in, a look at the climate drivers by lunchtime.