SA - SEVERE WEATHER UNFOLDING AND PERSISTING FOR LARGE PARTS OF THE INLAND.

For areas in the far west and the far east, you sit on the periphery of the worst of the weather for now, with the heavy rainfall and severe thunderstorm activity sitting over the West Coast, Eyre Peninsula through to the northern districts and the NT. There will be significant flooding in the Outback and this could cut off communities including the APY Lands. The Stuart Highway could also be cut through areas north of Glendambo to the NT border.


The thundery severe weather may begin to spread eastwards with the trough moving on, but there are some models that say, no hold your horses, the trough stays here, with high pressure anchored to the south with moisture and instability remaining deep.


Thundery weather will persist throughout the entire period, with some modelling suggesting that a second severe weather event may redevelop later next week to end the month.

FORECAST

Rainfall Next 10 Days

Exceptional and possibly record rainfall for interior parts of SA extending down into the western Agricultural Districts are possible through the coming week, with the most significant weather expected Friday through Monday. Round after round of severe thunderstorms likely over the interior and extending down into the central coastal areas. Some offshoot showers and thunderstorms may fan out to the remainder of the Agricultural areas during the weekend, but with the rainfall orientation running from northeast through to the southwest, many areas from Adelaide and points east may stay dry and humid with only isolated showers and thunderstorms. The trough gets a chance of moving east early next week meaning the coverage of thunderstorms may also increase for the east and northeast. Another trough may redevelop over the state mid to late next week with the potential for follow up heavy falls.

Thunderstorm Forecast Friday

Thunderstorms are expected to be ongoing from tonight through Friday, with severe thunderstorms highly likely. Heavy rainfall leading to flash flooding the main concern, there may be intense bursts of rainfall through the Outback leading to very nasty flooding. Damaging winds and large hail also a risk as well on the periphery on the main area of thundery rainfall band and heavy cloud cover.

Flash Flood Risk Friday

A very high risk of flash flooding through a large area of the outback with life threatening flash flooding possible.

Damaging Winds Risk Friday

Damaging winds are expected with thunderstorms that form on the edge of the cloud band. This is where the air will likely be warmer and more unstable.

Large Hail Risk Friday

Similar to above, the large hail risk found on the periphery of the cloud band but mainly in the western and northern aspects of the cloud band.

Riverine Flood Risk Friday through Wednesday

A very high risk of riverine flooding throughout large areas of the Outback with roads and communities cut. Some areas could see flooding for weeks as a result of this first event and the risk may be exacerbated by the secondary feature mid to late next week IF that does indeed verify, but we need to flag that.

DATA - Refer to the video for the breakdown of daily weather information for the short and medium term.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 16 Days

The short term offers that severe weather event over SA, that will be the focus of the forecasts for much of the outlook period. Heavy rainfall lasting for much of the period will result in flooding of large areas of the outback. Moisture will eventually spill eastwards into NSW and VIC with showers and thunderstorms increasing. This will be the case in southern QLD as well. For the north the wet weather is set to increase dramatically in the coming days. Modelling remains poor for the medium term, so focussing more on the short term, the pieces are in place. The monsoon trough over the north will bring a renewed burst of heavy rainfall and strong winds from the weekend throughout the remainder of the month feeding troughs over the southern and eastern inland of the nation, leading to more above average rainfall chances. I will mention that the tropical activity up north indicates the monsoon will remain in place over northern Australia and now is the time for people living in the north of the nation to be prepared for significant weather in the coming weeks with monsoonal break conditions ending.

00Z GFS - Precipitable Water Values - Next 16 Days

A very deep moisture source remains the dominant feature for much of the nation bar the far southwest of the nation and the eastern inland for a period this weekend as the high rotates through to the Tasman Sea. Humidity values will increase for most of the nation next week with higher temperatures and unstable weather also featuring. Where it rains, it will be efficient and productive weather.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to video for more information

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to video for more information

00Z GFS - Rainfall Accumulation - Next 16 Days

Refer to video for more information

A closer look in - this will change but gives you an idea it is a humid and unsettled fortnight on the way for most of the state.

More details coming up in the models and rainfall wrap for all you rain lovers!!!

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