It is a very active and dynamic weather pattern and once again we are seeing some high end severe weather across parts of the nation. This is currently evolving through the southeast with a low pressure system rotating through bringing windy weather with periods of rain.

As this system moves into the eastern inland, the trough and low is expected to run into the moisture streaming in from SA and the NT with significant rain and thunderstorms to develop from this morning with moderate to heavy rainfall. All modes of severe weather is possible.

The secondary low back over SA and the NT is expected to deepen further today and tap into moisture streaming through WA and the NT bringing widespread rain to SA and severe thunderstorms for northern areas into the NT with destructive winds, large hail and dangerous flash flooding.

The first low moves east tonight and clears a rainband offshore. The secondary low will approach tomorrow to VIC, NSW and QLD with rain and thunderstorms to increase with moderate to heavy rainfall. Along the trough which will move through northern NSW into QLD, severe thunderstorms with destructive winds, heavy rainfall and large hail can be expected in many areas. Along the path of the low, heavy to very heavy rainfall is expected south and east of the low with flooding developing.

There may be a gap between the trough and the low with lighter rainfall totals in this region which may be northwest NSW and southwest QLD. Will have to wait and see.

Otherwise the west is dry in sinking air and cooler southerly winds from later today, with the ridge clearing the low into SA. The state relatively dry after a very damp 2 weeks. The tropics will remain very active with showers and thunderstorms, mainly over the NT and Cape York.

Lets take a look


Rainfall Next 10 Days

Rainfall clearly is the heaviest over the coming 3 days for much of the southern and eastern parts of the nation, though the process of clearance has begun from WA, with the upper low and areas of rainfall moving east this morning. The first low pressure system and rain and thundery mass expected to increase this morning over NSW and QLD and then easing through VIC this afternoon. Heaviest rainfall expected through NSW and QLD with flash flooding possible. Severe thunderstorms also likely through NSW and QLD. Rain increases through western SA with severe thunderstorms also possible before that shifts further east to the Ag areas during Thursday and then eastwards later Thursday into Friday. That means a small break through QLD and NSW before another round of heavy rain and severe thunderstorms during later Thursday into Friday before clearing the eastern inland Saturday with drier air. The southeast may stay showery and wet with cold showery winds developing on the back side of the low. The tropics will see showers and thunderstorms contract northwards through this weekend with a drier airmass pushing north.

Thunderstorm Forecast Wednesday

Thunderstorms are ongoing from previous days activity along two troughs, one over QLD and NSW and another sitting over the NT and SA and creeping back into eastern WA. The main severe weather risks exist along these boundaries and to the east. The main risks are flash flooding and damaging winds. Large hail cannot be ruled out over southern NT and northern SA with a brief isolated tornado also possible. The weather will move east in all regions, with the storms in the east flattening to a rain band at night and the storms over central parts of the nation persisting well into the night.

DATA - More information can be found in the video.

12z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

The pressure pattern is very dynamic and energetic for the coming 3-4 days ahead of the low moving offshore NSW this weekend. That will send in a drier and more stable flow pattern away from the southeast of the nation for much of the weekend and into early next week. So a little break in the humidity and wet weather for Ag areas of the nation is not too far away. But between now and then, a serious threat from above average rainfall exists.

12z Euro - Precipitable Water Values - Next 10 Days

The guidance unchanged with those record moisture values over parts of the north, central and eastern areas of the nation being moved along by a surge of southerly winds coming up this weekend and a much more settled period of weather for much of the nation's interior with below average temperatures will continue from the weekend into next week with moisture returning from mid next week where we assess the rainfall and thunderstorm risks from that period until the end of the month.

12z Euro - Precipitable Water Anomalies - Next 10 Days

Excessive moisture values as mentioned above gets moved along by a strong surge of southerly winds this weekend but once the winds turn easterly and the northwest winds through west of the nation drags moisture in from the Indian Ocean, the forecast will turn more unstable.

12z Euro - Rainfall Accumulation - Next 10 Days

More information can be found in the video

12z GFS - Rainfall Accumulation - Next 10 Days

More information can be found in the video

12z CMC - Rainfall Accumulation - Next 10 Days

More information can be found in the video

More weather information coming up today looking at the medium term and the follow up rainfall potential from next week which is closing the gap of drier weather over much of the east and west.