SA - SITTING BETWEEN IT ALL, DO WE HAVE SOME CHANCE OF GETTING DECENT RAIN SOON?

It is amazing to watch the weather play out across the country and highlight the various climate zones that we live in. SA is constantly in a swing/battle zone for weather systems, we have seen that play out in recent days with the famous ridge blocking rainfall from the east and from the west leading to many frustrated locations looking for rainfall for the crops.


At this time, we are still looking at relatively light falls with the remains of a front coming out of the west, the system breaking down with the high in the east knocking the wind out of the sails, leading to a lot of cloud but only light rainfall developing from Friday.


The system quickly moves through by Saturday and that means back to dry, cool and windy weather for southern areas and drier weather with high cloud over northern areas who will be sitting under the moisture feeding through the jet stream.


Next week we start out drier with a high over the region, but it is expected to take a step back during Tuesday and this may open the door for a front to sneak through the south and southeast with showers increasing in these zones, but once again very little is expected to penetrate further north and east through the inland as the axis of this front peaks over VIC at this time.


Moisture increasing over in WA offers the main point of interest when it comes to rainfall for SA. There will be a large-scale rain event is possible over the outback of WA and that may start to move south and east towards the end of next week. Also, we will have moisture building through inland QLD as well with all of this folding into the state. What we need is a strong trigger to lift that moisture into meaningful rainfall and that is what we are waiting to see.


All the ingredients are there for above average rainfall across the nation as you can see, but it comes down to luck it seems in SA for that to come together at the right time of year.

FORECAST

Rainfall Next 10 Days

Rainfall is expected to be lighter for the state, especially away from the coast. There are very decent signals for moisture to spread across the country with light falls possible in SA, but the heaviest rainfall looks to be further east and further west of the state for now. A band of patchy rainfall is forecast to move through southern parts of the state during Friday into Saturday before the band of cloud and front move through to the east. There will be another front to approach the state’s southeast which could see showers increase again Tuesday with that weather moving on by Wednesday. Rain may develop over the northwest of the state with a larger cloud band developing over inland WA. The movement of this system remains to be seen but certainly with moisture sitting at excessive levels across the nation’s north and west, it will eventually come through the state with a front as is what is typical under such climate guidance.

MEDIUM TERM - May 19th-26th 2022

Rainfall Anomalies

Not much deviation from the previous update with the rainfall now expected to run through the jet stream but the highest impacts are forecast up over northwest inland WA and over the eastern inland of QLD through northern NSW. There may be some light to moderate rainfall running through northern SA, but it could bypass the Ag Areas where it is needed. Drier weather back over the north of the nation. The forecast confidence of the Indian Ocean making more of an impact across the country is currently moderate.

Temperature Anomalies

Not much change from yesterday with a warmer and more humid trend for the north and east with the positive SAM likely to propel moisture west across the nation. Cooler bias continues over in the west with the persistent cloud cover and rainfall potential ongoing via the jet stream.

DATA - Refer to video for more information and the model comparison and context about all the forecast products you see from me.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

The widespread rainfall over the east of the nation is beginning to wind down front he west, though we still have some heavy falls leading to flash flooding over parts of QLD and northeast NSW and residual flooding to contend with over the next few days. Out west we have widespread rainfall spreading throughout with a strong cold front, some areas have seen some heavy falls. Some areas passing 1 months worth of rainfall with this feature. The rainfall is spreading eastwards further, but weakening and light and patchy falls is forecast over the west of SA tomorrow and then onwards to the Ag Areas of SA and the southeast inland this weekend. We see things settle down over the weekend for most areas and into early next week. We watch the next rain band over the western interior next week and see whether we have another rain event emerge over the QLD with deep moisture returning later next week. Rain could also extend into NSW and the ACT once again later next week. The medium term is also looking very active.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture profile across the nation is excessive but starting to move east and northeast as a trough and low moves east through QLD into NSW. The moisture over WA is excessive tonight but starts to thin out as the front and trough in the region weakens and the upper-level winds take some of the moisture north and parts of the moisture into the southeast inland. The moisture profile becomes more seasonal for many areas by next week. However, the focus of further rainfall potential can be found over WA and extending through the interior via moisture along the jet stream and we could see inland rainfall chances coming up with moisture deepening over the eastern inland of QLD and through NSW. SA on this particular model sits between it all still, but with such deep moisture over the southeast and southern inland, we could see the rainfall chances extend through the state later next week into the weekend, then into VIC. You do not have so much moisture running through the jet stream and the rainfall chances remain at 0%.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - the rainfall guide is very poor from beyond the weekend with many moving pieces and a lot of moisture about that needs to be watched carefully. Your numbers will be chopping and changing from run to run so we will know more once we get to about Sunday but certainly interesting viewing coming up for the region. If you are living in a drier zone, do not be disheartened by that as your forecast will change.

More coming up from 8pm EST with a look at the models and rainfall, I will only share information that is in reasonable agreement as too much is too confusing and I only want to share what is plausible at this time, so stay tuned for that.


Also, a reminder that I am travelling tomorrow back home so I will have a brief update in the morning, but the next video will not be until the afternoon.


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