SA - FINE FOR THE INLAND FOR A WHILE AND WARMING UP - A FEW SHOWERS OVER THE SOUTH OF THE STATE.

Before then we have got an upper cold pool overhead tonight and that has seen cloud cover develop this afternoon with showers over the SA/VIC border but they are light and isolated. Likely to clear once the sun is down.


The broad areas of low cloud is in response to the cold air, but the close proximity to the high pressure, the cloud cannot rise into showers with the sinking air motion winning out.

Local frost is a risk in the east tonight, with winds over the EP likely to keep things just above frost level for now, but a cold night throughout. Severe frosts are possible northeast of Adelaide and along the Flinders and Mid North.

The weather turns during Friday afternoon into Saturday thanks to a cold front passing through WA today, which cuts off into a low pressure system to the south of the state, that system then weakening on approach to the southeast, on the northern flank of it, a few showers for coastal areas possible.


The rainfall light and patchy if anything over the west, maybe up to 5mm over the southeast however the system will be more productive over the eastern states as it finds more moisture. You can see the showers are strictly coastal at this time.

The weather will warm up dramatically in the new week as the wind flow turns northwesterly as a high pressure system strengthens over NSW and QLD sending in warm northwest winds. Some locations easily into the 30s, mid 30s over the northern inland.

Over the inland of QLD the moisture is expected to increase through the coming few days, leading to a storm outbreak there, and that moisture will move south and west through the state lifting rainfall chances for inland areas of SA.

That will be in part thanks to a strong cold front that draws in the moisture, draws in the warm airmass from the northwest interior and links up with cold air, bang!, we see a low pressure system form with a band of rain.

00Z GFS Surface Pressure Pattern for the coming 16 days

The pressure pattern shows the low-pressure system off the southeast coast of NSW bringing widespread showers to the east coast of Victoria and southern NSW. There is a trough that has worked north today and that will be the focus for widespread areas of rain during Friday. The weather is set to turn showery over parts of southern NSW and most of VIC on Friday with the trough and associated cold pool lifting out and moving east. The weather over the nation is being controlled by high pressure and that remains to be the case into next week. Coastal areas of QLD is the area to watch with welcome showers and storms forming along a pressure trough that is aligned through the central and northern inland with moisture streaming in from the easterly winds. The weather should turn more humid through the eastern inland next week, the moisture spreading through to central and southern parts of the nation ahead of a strong cold front. That front is expected to send temperatures way above the average over the eastern states. This may add the fuel needed to bring the widespread heavy rainfall so many are after (the not so many that don’t want either). The rain will progress through WA from mid next week, SA this time next week through Friday and then onwards to the eastern states from Friday into the weekend with moderate to heavy falls possible if it all comes together. The tropics will turn humid as the wind profile tends north-easterly over the region.

00z GFS Rainfall for the coming 16 days

Rainfall confined to two events through the outlook period for the southeast states, we have the low-pressure trough and cold air pool that is delivering showers to parts of the far east during today, that activity expected to increase during Friday as moisture deepens from the south and combines with the colder air, but all of that happening east of us. A trough approaches from the west tomorrow and that will likely bring a warmer northwest flow and a few showers as that dives to the southeast during Sunday. Another system approaches next week with a broad band of rainfall following some warmer weather across the region. The added warmth increasing the thermal dynamics and bringing about and higher chance of moderate rainfall with this feature. Another system looks to approach in the medium term as well but low risk of coming off.

00z GFS Precipitable Water Anomalies next 16 days

Modelling continues to support drier air over the nation being overrun through northeast part of the nation with trade winds and with another impulse over the southwest of the nation. This will start to erode the dominance of the drier air under high pressure and by next week as mentioned, we will have widespread moisture passing through from the easterly winds and then being pumped into the eastern and central inland of the nation. The trough over eastern inland QLD will bring showers and storms as the moisture is lifted through the region. A signal of the seasonal shift underway. A strong cold front and trough then runs into this moisture, that is still the case this evening. Through the medium term we will be watching the north of the nation where moisture increases and whether the Indian Ocean will decide to wake up and play a part in introducing rainfall through the north and west of the nation.

00z Euro Surface Pressure Pattern for the coming 10 days

The surface pattern pretty similar in the short term, the models only disagreeing on the timing of the troughs passing through the southeast inland tomorrow and how much moisture gets involved and drawn north and the trough and low how it evolves over the Bight and how much moisture gets involved in the system as it passes over the region. Over QLD, the model divergence continues through the early part of next week, Euro sees the storms over the northern parts of the state but the GFS has much more widespread precipitation. I will say that GFS has picked this week very well so will continue to side with this solution. Then next week the frontal system over WA that brings the widespread rainfall event from west to east, is anticipated to bring a very warm start to spring over the east and central areas of the nation, but for the west, much colder start to the month that usual. Over the north the tropics also becoming more humid with a northeast flow.

00z Euro Rainfall for the coming 10 days

The rainfall is less than the GFS for the upcoming 5 days with a drier airmass being depicted by the deterministic run of the Euro, but again the GFS has picked the placement of the elements better than the Euro of late. The Euro brings in a weak trough over QLD with scattered showers for the coast, more isolated inland with the chance of thunderstorms. Then all eyes focussed on the weather out west with the large scale wave of low pressure and frontal weather passing through from the west, which will headline rainfall chances for the nation next week, as it crashes into the moisture surging in from the easterly winds on top of the strong high.

00z Euro Precipitable Water Values next 10 days

The Euro has shifted away from the GFS with less moisture gradually building back up with widespread rainfall and storms developing first in QLD thanks to the trough in the region combining with onshore winds before that weather turns south to spread the showers down the coastline but in less coverage but again this could change. A series of troughs out over the west tries to bring in modest moisture through the southern and eastern inland of the nation this weekend but the drier air looks to win out there. Next week, once a high has re-established itself over the east, a stronger longer fetch easterly wind will propel the moisture inland to the NT and SA and this is swept up by a strong front which you can see leads to widespread rainfall developing across the nation and the moisture may build up further over northern Australia as the northeast flow continues over the north.

Rainfall for the next 10 days

The showers are expected to be few and far between this weekend with a weakening low pressure system and trough passing through, but what that will do is send the region into a warmer northwest flow. So dry for the coming 7 days for most of the inland with a high. Then we track the larger scale system from the west which brings a band of rainfall through from this time next week and then into the east, lingering into next weekend. The moisture does return after this period on some of the global modelling but the confidence is low on that. The Euro also much slower with the system and therefore you will not see the rainfall as early nor as heavy as it does not develop a low in full force. So the divergence continues, given that we are a week out from the system passing.


Tomorrow I will have the summer climate outlook for 2021!!




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