After a very productive 24hrs of rainfall for parts of the northeast of NSW, the weather is expected to ease overnight as a trough responsible begins to break down and high pressure starts to establish some rule over the state's weather.
A northwest flow developing this week, will send the region back into a very warm phase, with well above average temperatures over the western and southern districts.
A cold front meandering through the east, will lift north during the weekend, and may establish an unstable boundary over the southern inland regions, extending west back into the NT with periods of rainfall possible.
Lets have a look at the latest details.
Rainfall for the coming 10 days
Showers and storms over the southeast inland and rain over the east will largely clear overnight with a fine and settled pattern returning. A few showers possible over the western inland near the NT border as moisture moves west through the state. The weather turns warmer ahead of another system passing through the region from Saturday. That will bring a band of rain through southern inland areas this weekend with some models suggesting rainfall will continue for much of next week with east coast low potential. I am not drawing that in just yet, but the positive SAM phase may lead to more rainfall opportunities in the coming week for eastern inland QLD and NSW. The western and northern area could see some rainfall break out under such climate drivers with the warmer more humid air.
00z Euro Surface Pressure Pattern for the coming 10 days
The pressure pattern remains unchanged in the short term with high pressure dominating the east and sending in that very warm airmass. We then watch the strong cold front passing over the southwest of WA tomorrow and track that through the Bight Thursday and then into SA Friday an VIC through Friday night into Saturday and then into NSW Saturday with a few heavy falls along the journey from VIC into southern NSW. The band of rain extending back over the outback as well with the colder air surging north. Then a large high pushes in and noses out the colder air surging over the east out to the Tasman Sea, stopping the formation of follow up rainfall next week over QLD. The rain band likely under this scenario exits with the cold front, and I would be cautioning you to this outcome with a positive SAM phase possibly in play, this could see rainfall return to the east coast of NSW and QLD and possibly hang up the rain event over the east next week. For the remainder, once the front is through high pressure keeps you dry and cooler. The tropics see the odd shower and storm this week before a return to dry air.
00z Euro Rainfall for the coming 10 days
Rainfall is likely to remain along the coast tonight with clearing thunderstorms over the southern inland also clearing. Then dry weather for much of the inland tomorrow with upper heights coming up and the air drying out. The showers may linger over the northern tropical coast with moderate falls but inland areas turn dry. The next rainfall comes in with a trough later in the weekend over the southern and western districts, at this stage the models are mixed in rainfall distribution with falls moderate to heavy on the GFS and the Euro saying no, light rainfall pushing through and clearing early next week, so we will watch this closely. Hopefully better clarity coming tomorrow through Thursday as the models are fed with the real time data.
In stark contrast to GFS which shows widespread falls as mentioned in the video blog - basing this forecast off the SAM being in a positive phase!
00z Euro Precipitable Water Values next 10 days
The moisture over QLD is drawn west over the tropics and part of the moisture is drawn south into the cold front passing over the southeast and east. The moisture coming in with the front from WA is modest and sufficient for a rain band to form during tomorrow. The moisture will also follow the front but for SA the lifting mechanism to bring rainfall falls to the southeast as feared last week as one of the options due to the Tasman high. Then the trough over SA gets new life over the eastern states, invigorated by the deeper moisture layer leading to widespread rainfall reforming on the boundary as it moves throughout the southeast and eastern inland. Dry air likely to surge through following the front with a colder airmass to sweep the moisture north and east. The tropics will see a moisture increase mid to late week ahead of drier air surging north next week, perhaps the last dry surge of the season.
Temperatures are expected to be well above average as well through this period, but the colder weather next week is still very much on the table and this volatility in the high amplitude pattern will continue for a number of days on the models. So look for trends!
The SAM being in a positive phase may hold the clue as to why the rainfall bias is shifting over eastern inland portions of the nation and so will keep watching this trend and I would not be surprised to see that major rainfall event that has been forecast by some modelling in recent days to return to charts in the next few days for next week. Especially for QLD and northern NSW. That would leave dry weather developing for southern parts of the nation under such indications, with high pressure in place.
I will have another look at the potential rainfall event in the model rundown later this evening.