A blustery night with increasing cloud has lead to a warmer start throughout the inland with a front starting to move through this morning and areas of light rainfall has begun.
The rain will slowly extend north and northeast through the state today, but light falls less than 2mm expected for the northern inland areas at this time and dry along the coast.
The next ridge passes through on Thursday and mild dry conditions set to return, some areas of northwest NSW on Friday before a hot day Saturday with low 30s possible through outback NSW.
Temperature anomalies on Saturday.
A full spring preview with some areas up to 10-12C above normal for this time of year which will place many areas into the high 20s and low 30s.
The next front responsible for that heat incursion will sweep through the southeast of the nation, the northern flank clipping the state bringing areas of light rainfall to the southern inland.
Another front then approaches early next week, that system could be quite robust and produce a moderate rain band and a colder shift.
Still eyeing off that pattern flip later next week and that moisture over the northwest of the nation, can that come south or east?
12Z GFS Surface Pressure Pattern for the coming 16 days
The pressure pattern continues unchanged for the coming 5-7 days with the westerly wind belt continuing, however the ridge is now starting to beat down the intensity of the westerly winds, so while there are cold fronts impacting southern parts of the nation, inland areas are starting to see less rainfall from the weekend. The winds veer more northwesterly and we are seeing the upper air become more stable under the ridge. The ridge looks to sit further south for the week of August. There are signals that the weather may begin shift from mid month as we have been looking at, which still seems to be a fair assumption at this time as the westerly begins to retreat south.
12z GFS Rainfall for the coming 10 days
Rainfall becoming lighter which is expected under the pattern shift. So the further north you go, the less rainfall you will see, a bit like what QLD has been experiencing. The further south you go, the weather will be damp, but not as wet as recent weeks. The best rainfall will be for any region exposed to the westerly wind regime.
12z Euro Surface Pressure Pattern for the coming 10 days
The pressure pattern is starting to become less dominated by the long wave troughs throughout the outlook with a high pressure belt now starting to dig into the westerly belt. So while there are still frontal incursions through southern parts of the nation, they are less intense, less frequent and are producing less rainfall. Note the ridging over the southern states towards the end of the outlook which supports the shift in the upper level pattern. That will also move the moisture around and reorganise it over the northern and northwest of the nation, setting it in a position that favours better rainfall odds from mid August.
12z Euro Rainfall for the coming 10 days
Rainfall rule applies the same as GFS, the further north you go, the less rainfall you will see and the warmer your weather will be through the period, and the further south you go and if you are along the western slopes, the more rainfall you will see, but overall it looks to be half of what has been experienced in previous weeks.
12z Euro Precipitable Water Anomaly for the coming 10 days
This is the more interesting product, the moisture that is rolling through the nation. Now while the moisture content is high, it is not producing a lot of rainfall outcomes just yet, however this could change as the moisture starts to pool in unstable hot air over the northwest of the nation from mid week. You can see the moisture then surging south and southwest through the western interior of the nation towards a large cold front and upper trough which would then form a larger rain event from mid month. Again medium term forecasting carries low confidence and we will again classify this as a signal but certainly one too watch.
Rainfall for the next 10 days
Rainfall for the coming 10 days is starting to reduce as we see more high pressure in the second half of the outlook which is part of the pattern shifting. So rainfall post about the weekend may be close to 0mm for many areas in northern NSW and continuing dry into southern QLD. The rainfall will continue for southern NSW but the falls lighter and even starting to see the rainfall reduce for the Alpine areas and higher parts of VIC with the flow pattern stabalising. The wettest system appears to be today and maybe early next week but the models have been struggling with the system early next week, so a low confidence strap still applies to forecasting beyond Friday.
More weather details coming up.