A change is expected to roll through southern NSW as we track into Tuesday, that is after a fairly settled Monday with some cloud. A cold start should lift to seasonal weather and fine weather expected along the coast.
Tuesday we have a system that is still anticipated to surge northeast, on the western face of a long wave trough over the Tasman Sea. That will send up a cold airmass into Wednesday before conditions moderate rapidly with a weak high.
That high will clear skies and trap the cold air. It will set the stage for a very cold night into Thursday morning with widespread severe frost and a freeze likely for many parts of Agricultural NSW. The temperature guide would cause damage to crops and stress livestock.
A weakening low pressure system may bring patchy rainfall to western NSW Thursday afternoon before a stronger westerly change with gales and showers arrives Friday and persists through the weekend. The westerly wind belt is in full control for the coming period.
Lets have a look at modelling.
12Z GFS Surface Pressure Pattern for the coming 16 days
A fast flow pattern as described above is set to dominate the coming week and even the next 2 weeks. This has largely been unchanged with the state expected to see periods rain and showers from time to time over the course of the next 10 days, some bursts of rainfall moderate for the southern and central inland, some heavy falls over the GDR and Alpine regions. Coastal areas may get a kick of showers during Wednesday with southerly winds but otherwise dry weather as the winds back into the west again as the next long wave trough approaches with strong cold fronts. The weather looks likely to clear over the northern inland during next week with a high but with moisture and frontal weather lurking about the southern parts of the nation, the weather is highly variable in the medium term so watch this space.
12z GFS Rainfall for the coming 10 days
Rainfall largely unchanged from overnight with gusty cold fronts the main source of rainfall in the westerly winds. Those winds means that on and west of the GDR will be the focus of the rainfall with moderate to heavy falls, but in each run, noting the rainfall is improving once again for northern parts of the GDR up to about Tenterfield. The falls lighter further west. The low mid week could be a wild card system for the northern and western inland with some chance now of light rainfall bringing up to 10mm for many locations which would be handy for some. Then the frontal weather brings heavy rain and snowfalls to the southeast, moderate falls for the southern inland. More fronts next week could bring further falls but some evidence they could sit a little further south however I said that was a trend in modelling last week for this week, and here we are. So will watch trends.
12z Euro Surface Pressure Pattern for the coming 10 days
Not much change from overnight in the modelling. The low pressure system coming out of SA is expected to bring more rainfall than what was being shown last week for Thursday, so that system needs to be watched as it could surprise. Showery weather ahead of that with a strong cold front tomorrow will bring falls of 5-15mm to those on and west of the GDR and not much to those further east. It will be cold! Then the next frontal waves come in over the latter part of this week into the weekend with a chance of gusty winds and heavy rainfall over southeastern areas. There is still the risk of severe weather with this feature as the parent low pressure is at 965hPa just south of Tasmania, which would bring land gales with damaging gusts to those on the GDR and along the coast.
12z Euro Rainfall for the coming 10 days
Rainfall reflects the westerly wind pattern, a touch more in the low pressure this morning as opposed to last nights run. That would benefit the west of the state with moderate falls possible so will watch trends. The weather continues to support zonal flow and fast moving cold fronts with moderate falls to those areas that were damp last week. So the southeast areas west of the divide and along the GDR up to about Tenterfield would do the best, but not ruling out moderate falls for those over the western inland.
Rainfall for the next 10 days
Rainfall largely unchanged in the spread, but I have lifted totals in response to the low pressure system bringing a touch more rainfall with deeper moisture available with that mid week and along the coast with a few showers thanks to southerly winds mid week. A stronger system later in the week likely to bring back wet weather back the GDR, heavy falls over the southeast. More wet weather continues into next week with further frontal weather, however the rainfall will be favouring southern inland areas and drier weather for the northern inland.
More details to come on the systems moving eastwards this week, later this morning and this forecast updated this afternoon.