An active weather period continues for the southeast states, including NSW, which is expected to see a number of systems passing through the fast flow pattern.
Tonight, areas of rain with a few thunderstorms and hail over the inland with snowfalls down to 800m will clear. A ridge passing into western NSW on Wednesday will begin to clear the skies.
Then a very cold night on the way for Thursday morning, where frost and a freeze is likely to unfold, with no real change in the guidance for that severe weather event, which could bring damage to crops during the course of that snap frost.
Quickly following that frost will come thickening cloud and areas of rain, with that rain moving into a very cold airmass, leading to the rain turning to snowfalls above 600m across southern and central NSW. It will all come down to timing, but that could surprise a few towns with more snowfalls than rainfall. Some reasonable signals for moderate falls in the Lower Western bordering SA and VIC. That would be welcome for communities there, but that system will be a cold rain throughout its duration as it passes through.
Friday that rain tends to showers in the east, but the strong cold fronts will arrive during Saturday with a burst of bitter westerly winds and the chance of further low level snowfalls, severe winds and high risk to stock that are exposed to these conditions. Crop damage from hail is also possible if the cold air field can graduate further north. That would see a high impact event extend further north so this week there is a lot to keep an eye on
In the medium term, more frontal weather next week after a brief reprieve.
Lets look at modelling.
00Z GFS Surface Pressure Pattern for the coming 16 days
The surface pressure pattern continues to remain unchanged for the coming 10 days and really the next fortnight which is quite a remarkable run of westerly winds. The front in the east tonight lifts out. A weak ridge will pass through during Wednesday clearing skies but setting the stage for a very cold start on Thursday morning. Rainfall quickly moves in during Thursday which may start to bring moderate falls over the Lower Western and also fall as snow above 500m if the rainfall can run into that very cold air. Then a weekend of wild winds and widespread showers will see more moderate rainfall for the southern and those west of the divide. New frontal weather can be seen next week and some large cold blasts into early August, but we will just flag that now as the models saying no change in the westerly wind belt dominating NSW.
00z GFS Rainfall for the coming 10 days
Rainfall coming up over the southwest of NSW with the systems rolling through Thursday and again Saturday, with some areas receiveing 20mm which will be useful. The rest of the state more moderate rainfall for those on and west of the divide, heavy at times over the southeast where it will fall as snow. Lighter falls further up the NSW divide, but again some of that could also fall as snow. Dry along the coast, though a period of strong and gusty winds and showers on Wednesday may bring 5-8mm for some regions. Then the rainfall returns with a few fronts this time next week, those could be a little further south, but could bring rainfall to the southern inland the southeast.
00z Euro Surface Pressure Pattern for the coming 10 days
The Euro is a little drier for the southeast tonight but the systems coming through are vigorous so I am not buying the lighter falls for parts of southern inland and Alpine areas during this week into the weekend. There is more rainfall expected to develop from the west at the very end of the run. Note the large long wave trough building over WA, that is tapping into the moisture offshore and will likely come south and east, models will start to pick that up as rainfall.
00z Euro Rainfall for the coming 10 days
The falls are lighter tonight than GFS, this morning, it was the other way around, so for me the rainfall forecasts remain unchanged for now as we track the frontal weather through the coming 10 days. Falls could be heavier at times than what is being shown and snowfalls also moderate to heavy at times.
Rainfall for the next 10 days
Frost Forecast for Thursday morning
Another heads up ahead of the weekend cold snap that this severe frost event could bring damage to crops and stress out livestock with temperatures in many areas along the divide and slopes dropping below -5C for much of the night.
Freeze Forecast for Thursday morning
The temperatures could be even colder for some locations with the temperatures down to -8C for some locations over the GDR including areas such as Canberra, Cooma, Goulburn, Crookwell, Orange, Glen Inness. These conditions may bring up the chance of the rain coming in during Thursday falling as snow.
Snowcast for the next 10 days
Significant snow is falling over Alpine areas tonight and more to come over the next week to ten days should total 1m for many of the resorts, possibly more if the system move further north. For snow fans another 50cm is possible beyond this period, so the base could top 2.5m once this is done for the sequence which would be the deepest levels it has been in years.
More weather details to come - it is going to be a busy few weeks!