The seasonal shift is continuing across the nation as we track through the next week, we are seeing that early shift most in the temperatures. But some hints are also occurring up through QLD as well.

Moisture is beginning to deepen over the north this weekend and a weak trough over the northern interior may trigger a few shower and thunderstorms inland of the coast, mainly about the sub tropics and triggered by the afternoon day time heating process. You can already see the moisture moving south through the state as the winds turn northeast to easterly.

The moisture has already begun to seep south today and this will fuel the risk of thunderstorms through inland areas during the latter weekend and into next week. There is a low chance tomorrow aver the north.

This chart is likely to get a good work out this season!! Minimal chance of thunderstorms along the dry line/trough inland of the coast tomorrow.

Elsewhere, the weather is expected to turn warm, with well above average temperatures expected for many areas of the nation including QLD next week. You can see the impact of the change passing through the central parts of the nation dragging down the desert air into the eastern inland.

There is a major system expected to approach next week which is chopping and changing as expected and that will persist through the weekend and into next week as we get a better handle on how it performs in response to the weather in the Tasman Sea.

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 which is in the process of leaving the region overnight into Saturday. The weather over the nation is being controlled by high pressure and that remains to be the case into next week with a warmer northwest flow developing as the high consolidates over NSW, this leading to a very warm spell of early Spring weather. 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, that coverage could become a little heavier for the coastal areas between Proserpine and Mackay. 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. The systems strength and timing of the system will continue to chop and change as we wait for the system to initiate in real time and until such time I can only give you a guide. Once the upper air data is real time data, then modelling will improve. At this time 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

The major rainfall expected for the nation is that large scale event coming through next week from WA, through SA and into the southeast areas. Some heavy falls are possible in the southeast with this feature but again I can be more specific next week as better data is fed into modelling. In the meantime, the weather improves over much of the inland with above average temperatures returning and clearer skies. A weak trough over the south and southeast this weekend may bring showers, but that system may also help to pull a trough down through QLD and produce showers and storms for eastern inland parts and along the coast with patchy falls. Onshore winds could bring a few showers from time to time over the southwest with light falls expected.

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 as I continue to mention daily, 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. One of the signals that the seasonal shift is underway. A strong cold front and trough then runs into this moisture – how that looks will continue to chop and change throughout the coming days. 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. The longer term modelling today has shifted to show a very wet 4-6 weeks coming.

00z Euro Surface Pressure Pattern for the coming 10 days

The surface pattern pretty similar in the short term, 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. The next 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, that trend continues for the nation. Over the north the tropics also becoming more humid with a northeast flow. Again the modelling is supporting a more active few weeks on the way beyond this period.

00z Euro Rainfall for the coming 10 days

Euro brings in a weak trough over QLD with scattered showers for the coast, more isolated inland with the chance of thunderstorms. The main weather to watch will be 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. The system could be interrupted by the Tasman Sea blocking pattern as well so will have to see how that impacts its progress and development. But otherwise the weather becoming warm to hot with increasing rainfall chances for the east next week.

00z Euro Precipitable Water Values next 10 days

Largely no change in moisture spreading throughout the nation, 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. In the longer term I am expecting more moisture to dominate the charts as we go through September. That is a gut feel, no scientific basis for that, however I have been watching weather for 25 years and these seasons can shift very quickly!

Rainfall for the next 10 days

Tricky forecast, plenty of moisture coming in, but does it get lifted into heavy rainfall for the central and northern coast and adjacent inland? That will be the trend to watch in the coming days. Clearly the wettest weather is expected from Sunday through Tuesday with the trough sharpening and the moisture most deep over the north during this time. The moisture will spread west but the trough pulled offshore and weakened by a stronger high building back in over the state. Heights coming up to suppress the convective potential. Then we watch the major system rolling through the south of the nation from this time next week. Inland areas dry for the next 7 days for now.

It is the weekend and I will be having a little rest tomorrow, another update tomorrow afternoon and then full forecasts back from Sunday.

15 views0 comments