But the southwest and west of the nation remaining cooler than normal with onshore winds, near ridging that is near stationary over the southwest Indian Ocean. The weather is likely to remain very hot under the heat dome through Central Australia, a large upper high over the tropical north supporting very hot weather for the next few days.

Troughs working through the Southern Ocean will clip the southeast and south of the nation bringing the heat down from the northwest via a northwest flow. The heat then moving into the eastern inland and mixing with modest moisture levels to produce showers and thunderstorms along the troughs moving through. The one today and the one coming through on Saturday and Sunday could see a few severe storms develop.

For northern Australia, that is where the more widespread rainfall is expected through the short term, with another trough forming at the base of the Top End and creating large clusters of showers and thunderstorms. Some of the storms may be severe Friday through the weekend given the very high instability levels, thanks to high heat that is building throughout the interior. So be weather aware this weekend through the region.

The weather is expected to turn wetter and more humid as we approach Christmas but more likely as we finish 2021 and kick off 2022. This may set the stage for severe weather events to return and flood risks increasing.

Lets take a look


Rainfall Next 10 Days

Rainfall still following the same script as we have been seeing over the past few days, the short term offering a few troughs over the southern parts of the nation, leading to bursts of showers and thunderstorms for the eastern inland, but the coverage of thunderstorm activity is hit and miss and therefore no widespread rainfall event is expected for the south and east. The northern tropics are getting wetter as we go with the chance of heavy falls developing from the weekend and through next week as a tropical wave moves through. That moisture will be spreading south into troughs in the west and another trough over the east from next week, so expect the showers and thunderstorms to increase as we get into Christmas.

Thunderstorm Forecast Wednesday

Showers and thunderstorms are forecast to become scattered over the southeast inland of NSW and eastern VIC with the highest risk of showers and thunderstorms expected during the afternoon and into the evening. Storms carry the risk of damaging winds and heavy rainfall leading to flash flooding. Large hail is a low risk. Elsewhere, a few thundery showers expected over the inland of WA into western SA and a low chance up to the northern tropics this afternoon with gusty winds possible but no severe weather anticipated.

Thunderstorm Forecast Thursday

A few showers and thunderstorms possible over the northeast of NSW and southeast QLD with storms turning severe in a small area along the NSW/QLD border. Damaging winds and heavy rainfall leading to flash flooding possible. Scattered showers and thunderstorms for the northern tropics becoming more widespread about the Top End. Isolated showers and thunderstorms possible about the southeast of NSW near a stubborn trough.

Thunderstorm Forecast Friday

Severe thunderstorms are possible over the northern Top End with a boundary moving out of the Roper and running into a deep layer of moisture. Some thunderstorms carry the risk of damaging winds and heavy rainfall leading to flash flooding. Thunderstorms continue for the northeast of NSW and southeast QLD with some of these storms turning severe with all modes of severe weather possible. A new trough in WA will move into SA with elevated thunderstorms moving southeast into southern SA at night.

DATA - You can see the GFS comparison in the video.

12Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

The pressure pattern remains consistent, the fast flow pattern to the south of the nation creating the roller coaster ride in terms of temperature variability through to next week with the last of the troughs moving through early Monday over Tasmania. The trough over the weekend for southeast and eastern Australia may pack a punch in the form of showers and gusty storms, that activity contracting north into QLD and northeast NSW. Then we see the easterly winds begin to become the dominant wind field. That will support moisture deepening over the northern and eastern parts of the nation and the return of showers and thunderstorms to large areas of the nation from late weekend and then this activity spreading south and southwest as we move through towards Christmas. The rainfall spread and intensity is expected to increase further beyond Christmas towards NYE for northern and eastern Australia with heavy falls possible not only about the north, but over the inland of QLD, NSW/ACT and into northern SA. As I keep mentioning, factor this period right now as being the driest it will be for a while and prepare for another prolonged period of humid, wet and stormy weather. The west, remaining below average in terms of rainfall and temperatures for a good part of this period, perhaps warming up over Christmas, but no baking hot weather at this time for the SWLD, but interior parts will remain hot.

12Z Euro - Precipitable Water Values - Next 10 Days

Moisture is expected to pool over northern Australia through the outlook period and it won't be until we get to next week that the moisture starts to shift south into troughs and then we see that moisture become stubborn over the western and eastern interior. The southern coast may escape the humidity until we get to Christmas and with the warmer temperatures developing, a humid and unsettled warm festive period is likely. The weather is expected to remain humid and unsettled for the remainder of 2021 for large parts of the nation with increasing rainfall chances. The far west is the place to be to avoid the persistent warm, soupy air.

12Z Euro - Rainfall Accumulation - Next 10 Days

More of this discussed in the video.

12Z GFS - Rainfall Accumulation - Next 10 Days

More of this discussed in the video.

12Z CMC - Rainfall Accumulation - Next 10 Days

More of this discussed in the video

I will update the medium term forecast today and take a look at that moisture returning and the risk of rainfall increasing through Christmas to the end of the year for many of you.