The very hot weather over the interior is expected to continue for the next 2-3 days as a trough through the south begins to shift northwards and allow for a wind shift into the south to bring in a milder change to the south from early next week.
Before then, it is set to bake with excessive heat, some locations into the mid 40s for a number of days and a very dry airmass.
Up north, the above average temperatures are forecast to stick around until the weekend, when the coverage of showers and thunderstorms begins to increase and this hopefully allows temperatures to come down from their excessive levels.
The wet weather over the north is expected to increase further over the weekend and more likely next week as a tropical wave begins to move into the Top End and this could flare up a tropical depression as we move over Christmas and into New Years Eve.
This would not allow for further heavy rainfall to develop, but also allow for temperatures to come down from their excessive levels as the moisture runs south and east from this area of disturbed weather, which at this time is being modelled to sit offshore the Daly Coast.
Lets take a look
Rainfall Next 10 Days
Rainfall is anticipated to increase from the weekend with deeper moisture available and a trough lingering throughout the base of the Top End contributing to more thunderstorm activity than what we have seen in recent times. The moisture also expected to increase from the north and east and feed this trough, so more cloud cover and rainfall will lead to lower temperatures. There is a tropical wave that will pass over the Arafura and Timor Sea through this time next week which will bring up the chances of showers and thunderstorms but also the risk of a tropical depression, leading to heavier rainfall emerging for the Top End. The moisture eventually will spill further south into central and southern areas with more chances of rainfall returning over Christmas and into the New Year for this region.
Tropical Depression Risk - December 23-30 2021
The area of interest sits over the Timor and Arafura Seas through this period. This will continue to help increase rainfall and thunderstorm activity while it organises offshore. The risk is relatively low to moderate.
Thunderstorm Forecast Friday
Thunderstorms are following the same script and impacting the same areas this afternoon and again on Friday, however the air aloft is a little more unstable and colder and will support more widespread showers and thunderstorms on Friday afternoon with some storms turning strong and gusty at times, especially over the Katherine and Darwin Daly regions.
DATA - Refer to the video for more details!
00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 16 Days
The pattern from now into Christmas remains largely unchanged from this morning's analysis so expect the confidence to remain fairly low in the placement of moisture and troughs through the coming days, that is due to the models trying to figure out what the monsoonal weather will do north and east of Australia. More information on that in the video.
00Z GFS - Precipitable Water Values - Next 16 Days
The forecast confidence is quite low on all elements and this will play havoc with the moisture spread throughout the nation in the short and medium term. The one system that does offer a higher chance of spreading moisture southeast and east across the nation is the trough passing through this weekend, no rain expected from the system as it passes through drier air over SA and WA but once it moves into eastern VIC and into NSW, it will find the moisture and see rainfall increase. Beyond then the moisture builds over the northern tropics and things start to look very unstable over the northern tropics moving forward into the end of year. Where the tropical weather goes, so too will the humid weather and rainfall chances.
00Z GFS - Rainfall Accumulation - Next 16 Days
More details in the video.
A closer look in - note the numbers move around over and over again in relation to the tropical low off the northwest and the monsoon trough forming offshore north and northeast. More details coming up at 9pm EDT
A broader look shows the moisture creep in the medium term, but it will chop and change.
More to come after 9pm EDT on all things rainfall, there is little confidence in the medium term with the tropical weather playing havoc across the agencies so remember, LOW CONFIDENCE nationally!