SA - A WEAKENING TROUGH BRINGS LIGHT RAIN AND THUNDER TO THE WEST - DRY ELSEWHERE.

The blocking pattern over in the east is likely to spoil the rainfall chances yet again for Ag SA with the system coming through WA bringing 1-2 month's rainfall, being forced south and weakening as it hits a broad high pressure system and trough over in the east. That block keeping the stable drier airmass in place for the east.


The front and trough may push far enough east to bring light rain and a few high based storms tomorrow before it weakens tomorrow night. By Thursday, there won't be much evidence of that system with high cloud left over.


Friday through the weekend, we are dry and settled under an upper high with light winds. The weather beginning to warm up from about Sunday as the winds tend northeast to northerly.


Next week could be quite warm to hot with a northerly flow. From about mid next week, watching that moisture over the southern NT, eastern WA and throughout the APY Lands. That may begin to shift south with the introduction of thunderstorms and showers for northwest areas, creeping southeast throughout the last few days of the month, just outside of my 10 day forecasts.


That would be the next chance of rainfall for the state.


Lets take a look

Rainfall next 10 days

Not much on offer for now, with high based showers and areas of light rainfall tomorrow bringing spits and spots to some NW areas. A stray storm over the far northeast is possible with the trough as it exits during Friday. The weather remaining dry elsewhere with perhaps morning drizzle and light showers as the flow turns southerly over coastal areas. The next rainfall as mentioned just knocking on the northwest corner from mid next week, that then moves south and east.

Thunderstorm Forecast Wednesday

Thunderstorms are possible through western areas during Wednesday with the chance of gusty winds. Not much in the way of rainfall as the lower levels will be quite dry and a lack of trigger despite the elevated PW values.

Damaging Winds Risk Wednesday

A low chance of damaging winds with high based thunderstorms that form, IF they form, through the region identified. Raised dust will occur IF the thunderstorms and winds eventuate but it is a small risk.

DATA


Euro 00z - Surface Pressure Pattern and Rainfall Distribution - Next 10 days

The pressure pattern is slack at the moment away from the west, with a blocking pattern setting up over the Tasman Sea which is blocking the passage of a strong complex change passing through WA today. We will see a trough that is along the NSW coast with a weak low drive showers and storms tonight and again on Wednesday. The system over the west will collapse over SA and be pushed south of the continent because of the block over the Tasman which we have spoken about, but a trough will remain over the land and become ill defined and devoid of moisture so it will pass through SA, most of western NSW and VIC in dry fashion. From Friday, as that system begins to move further east, you will see that system emerge into showers and thunderstorms for eastern NSW and QLD again this weekend. Another system will approach WA early next week and run into the Bight this time next week and likely help to pull down moisture from the tropics via inland WA and SA to increase the showers and thunderstorms risks over SA and VIC through NSW at the end of the run.

Euro 00z - Precipitable Water Anomalies - Next 10 days

No change from this morning or indeed yesterday. The dry air circulating around the southeast and central inland will largely remain trapped under ridging throughout the remainder of this week leading to the driest weather VIC and parts of NSW have seen in quite some time. The southeast and east coast sits under low level moisture and with weak troughs passing through, showers and thunderstorms are expected to form along these as they meander through, especially over eastern NSW and QLD. Some of the storms again in the short term forecasts could be severe. Over the tropics, deep moisture is pooling and will be dislodged from the tropics and sent south through the continent next week as the upper air flow turns northerly and helps to propel the moisture into a developing trough over southern WA and into SA later in the outlook period. Overall a typical late October look.

Euro 00z - Rainfall Accumulation - Next 10 days

Rainfall is becoming very hard to draw on charts when it looks like this. After the rainfall over the SWLD of WA is through, the rainfall will be derived from showers and thunderstorms, your number will vary and the distribution will be uneven so that is the best I can offer. The next widespread event is towards the end of the month, timing of that system is the issue more than whether it will happen or not.

A closer look in - note the showers and thunderstorms in the forecast, how can you draw a chart on that!!?

GFS 00z - Rainfall Accumulation - Next 16 days

Refer to the video for more

More details on all things rainfall after 9pm EDT with my model wrap.


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