A low pressure system is now bombing over the western Tasman Sea, close to the NSW coast, bringing areas of rain, gusty winds and cold temperatures.
The low has formed nicely offshore and is deepening this evening, hence the winds are increasing.
You can see the eastward progression of the low, with rainfall amplified over the coastal areas of NSW. Drier air keeping skies clear over western parts of NSW.
The bulk of the rainfall is expected to run along the coast as the low slowly moves east, a strong and gusty southerly flow persisting overnight and easing during Wednesday morning.
For inland areas, we have to deal with the colder clearer weather further west, this may lead to areas of frost and some of that could be severe in the shadow of the GDR with light southerly winds dropping out.
Warnings are essentially coastal with the main risk now for damaging winds tonight and through Wednesday morning as the low moves off.
We have also got another cold night on Thursday which I think could bring the chance of more widespread frost and the potential for severe frosts throughout the inland parts of the east.
Then temperatures will warm up from later this week, another few below average days are possible through Thursday. There is the a cold pool of air sitting over the southeast which may trigger some cloud and showers Friday as it ingests some moisture from the departing low, then clearer weather into Saturday ahead of yet another system over the Bight.
Temperatures are expected to remain near or below average now right through until the weekend, so the ground temperature won't be recovering much after this cold burst of rainfall.
Lets look at the weather heading into next week.
00Z GFS Surface Pressure Pattern for the coming 16 days
The low pressure system offshore the east coast will continue to move east, clearing skies expected for much of the inland during Wednesday after a cold start over many states west and north of the divide. Then we are looking at a front moving through WA, bringing the focus of the wettest weather back to the west coast of the nation. That system will then move into the east, bringing up the chance of showers along the WA coast. Out east, another trough and cold pool of air will create another burst of showers over the southeast with below average temperatures. That weather will then clear east. A low pressure system will develop in the Bight, the remnants of the front from WA, this will move steadily east. As it does, it will cause an upper trough to deepen over inland QLD and NSW, that trough linking into moisture to create showers and storms, the most widespread falls for QLD. The showers and storms will then continue for early next week over QLD. Another stronger front emerges from WA and that is likely to move east next week. The tropics will remain active tonight and then dry out tomorrow before the humidity returns next week.
00z GFS Rainfall for the coming 16 days
Rainfall event for the east now coastal with the inland turning dry and colder The air is drying out west of the divide so reduced rainfall likely now until the next trough during Friday for southern parts of the nation. The west is where you will find the next wave of low pressure bringing rainfall, that happens for SWLD of WA by Thursday with moderate falls. Then another impulse of moisture running through the eastern parts of QLD will link up with a trough while another trough and low moves in from the west over SA into VIC invigorating the weather over the eastern inland, widespread falls are possible next week, but determining the scope of rainfall is still yet to be seen. Then another stronger front mid to late next week brings rainfall back to WA, that spreads through SA and likely through the southeast states. More rainfall opportunities roll over southern and eastern Australia through early September.
00z GFS Precipitable Water Anomalies next 16 days
The PW anomalies are telling, we can see that dry air advancing over wide areas of the nation in line with the southerly wind shift over the past 24hrs. Then note the moisture over WA and more pronounced over QLD surging south and southwest through the east, lifting rainfall chances up for eastern inland QLD and into NSW. That moisture is then held in place over QLD for much of the outlook and as I have pointed out in recent days, while the modelling changes with the rainfall distribution, the bias is out east, while the west will see rainfall, however not as frequently. The frontal weather as they approach the east, may run into the moisture through the eastern and central inland of the nation.
00z Euro Surface Pressure Pattern for the coming 10 days
The Euro moves along the east coast low with the weather easing over the east during Wednesday. The colder air will surge through as dry milder air for the northern tropics during Wednesday, flushing out the humidity. Then we watch the front moving over WA, tonight the Euro has weakened that system more than the GFS, so under this guidance, a few shower and milder weather developing for the west, that system then rolling through the Bight during Friday. On Friday another trough over the southeast may trigger further showers with cold air dissolving over the region. During the weekend, moisture surging through the tropics may move further south and bring cloud, with showers and thunderstorms about the central and eastern inland at this stage, the coverage not as widespread as GFS which has moisture surging further south ahead of the trough coming into the southeast over the weekend. That will bring showers to VIC and NSW. Otherwise the stronger system to watch next week is the feature passing through WA then peaking through SA and may develop into a low pressure system over southern and eastern Australia with significant rainfall a chance. Ahead of that system, temperatures will finally return to normal and then above average.
00z Euro Rainfall for the coming 10 days
Rainfall over the east has eased so high pressure is dominating the nation, southerly winds in the east keeping the showers off the NSW coast but running them into southeast VIC with moderate falls. Then the west will see a weak cold front with a few showers and less rainfall if this is correct. The showers continue through the weekend over the west with light falls. The main area of precipitation will be over QLD with the developing trough and easterly winds. This could see some areas record their heaviest rainfall for about 8 weeks. A stronger system will pass through the west next week, that system then introducing rainfall through SA and into the east after this period.
00z Euro Precipitable Water Values next 10 days
You can see the battle between the elevated PW values and the drier PW values playing out on the models, the GFS wetter than the Euro, bringing up rainfall chances throughout the nation. The GFS was the first to pick the rainfall event that passed through the southeast in recent days. Note the moisture also starts to increase for areas of inland WA through SA ahead of frontal weather, lifting rainfall chances mid to late next week.
Rainfall for the next 10 days
Rainfall will be widespread along the coast and heavy at times this evening with a gusty southerly flow, damaging winds are easing for the east coast tonight and the dangerous surf also easing too by Wednesday afternoon. The weather is expected to dry out further over the inland for a number of days though showers may return with a trough moving through during Friday, mainly for southern inland areas. Showers may also break out this weekend with a trough moving down from QLD into the northern inland and over the western inland from Saturday and spreading throughout Sunday, both systems need watching as they could produce more rainfall than what is being indicated now. Next week the major rainfall event will be up over parts of QLD and moving through WA into SA by the end oft he period.
I will have more from 7am.