I hope you are all having a great weekend, the weather is behaving for once! Very settled for most of the nation with a large and unusually deep dry airmass across a large section of Australia, combined with high pressure, that is leading to clearer skies. However, the Summer heat is building in response to the clearer skies and after a wet few months, this will be the driest it has been for a long while.
The drier air means it is much more efficiently heated so you will see a much hotter week away from the coastal areas.
There will be a few troughs floating about, but because the air is devoid of deep moisture for a while, only isolated showers and thunderstorms can be expected at this stage. The more scattered falls will be found over the tropics, but even there, the coverage will be below average for a while.
The humidity does return from the weekend into the week leading into Christmas and that is where we will likely see the humidity increase, the temperatures reduce and the rainfall increase. So the end of the month, as expected looking more unsettled and remaining warm for most areas.
Rainfall Next 10 Days
Rainfall is expected to be fairly lean today through this week in comparison to the previous 12 weeks, large scale pressure keeping things nice and dry for many of us. The only wet spots will be the far north of the nation and western Tasmania with the monthly westerly flow passing through. The moisture is set to deepen though as we get into next weekend and the week leading into Christmas and rainfall chances are expected to go up. In the short term, a middle level trough over the southeast with a southerly change may bring a burst of showers and thunderstorms, that could create falls of 20mm for some, and isolated showers and thunderstorms for the east coast at times, east of the dividing range, also could see rainfall totals of 20mm. The west can expect hit and miss showers with falls less than 10mm generally and that applies to a cold front passing through later in the week. Much of SA, VIC, western NSW and QLD should remain dry until about the 20th of December at this time.
Thunderstorm Forecast Sunday
Thunderstorms are expected to develop over the eastern third of NSW north of Goulburn this afternoon where convergent winds be. The storms unlikely to be severe about the GDR but heavy rainfall with slow moving storms is possible. Coastal areas should miss out with the stable onshore flow. Much of eastern QLD carries the same risk of thunderstorms, the coverage may be a little more widespread. A trough out west may trigger scattered showers and thunderstorms during the afternoon and evening, but being so elevated and the air dry, not much rainfall, if any, is expected. The storms over the tropics, mainly about he western Top End and through the Kimberly.
Thunderstorm Forecast Monday
The thunderstorm activty over the east thins out a bit during Monday as the ridge strengthens over the region. The storms isolated along the ranges and contracts north through Cape York. The trough out west continues to fuel high based thunderstorms into western SA and much of inland WA. The heavier rainfall with thunderstorms can be found over the tropics. No severe weather expected
Thunderstorm Forecast Tuesday
No change expected to the change sweeping through the southeast, in fact coverage may be a little more widespread than what I have drawn in here and will review later today or tomorrow. The north still with the routine showers and thunderstorms extending into the central parts of WA. The rest of the nation is stable with a fair amount of dry air.
12Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days
12z Euro - Precipitable Water Values - Next 10 Days
12z Euro - Rainfall Accumulation - Next 10 Days
Showers and thunderstorms to increase through this period up over the northern tropics as the moisture returns and more favourable upper level winds develop, pooling the moisture in place. The southeast may see a fairly robust shower and storm outbreak mid week with some OK totals and then another system will approach at the end of next weekend into the 20th more rain and thunderstorms. The west remaining dry for the most part with fluctuating temperatures. The south of the nation west of a line from Melbourne to Dubbo should see little rainfall over this period.
12z CMC- Rainfall Accumulation - Next 10 Days
Showers and storms over the northern tropics should become more numerous through the outlook period. The coverage of moisture increasing over the southeast during mid week and again during the early part of the following week. Probably too dry for eastern QLD through this time but the far west should remain dry away from the SWLD. The mid week system may surprise in terms of showers and thunderstorms becoming more widespread.
12z GFS - Rainfall Accumulation - Next 10 Days - LOW CHANCE
Not a whole lot if you take this as the gospel, as outlined above, the two troughs, one in the west and the other in the east should provide the scattered showers and thunderstorm activity at times during this period. Over the northern tropics is where you will find the wettest weather.
12z GFS- Rainfall Accumulation - Next 16 Days - LOW CHANCE
The 16 Day GFS has not much and I think is running too dry for the period, so expect this to change, given the ensemble data set has much more rainfall for the nation. The north will see an increase in showers and thunderstorms next week.
More details coming up throughout the day plus your Autumn Outlook for 2022.