The south and southeast seeing an increase in temperatures as we move closer to NYE, it wouldn't be NYE in the south or east if we were not baking! Temperatures will be dry and windy as well with a high planted out over the east.

For the north of the nation, monsoonal break conditions are extending across large parts of northern WA, the NT and will arrive over FNQ during the latter part of this week with the tropical low moving offshore and to the south, detaching from the monsoonal trough which will head north.

The overall pattern in WA is settled and Summer like with the ridge passing east and a new ridge approaching from the west, offering some relief for the SWLD and coastal areas, before temperatures climb once again during the weekend and into next week.

Lets take a look


Rainfall Next 10 Days

Rainfall remains unchanged with the monsoonal break conditions over the north leading to more scattered falls with the widespread rainfall contracting through QLD and clearing by the end of the week, with some locations set to see 200mm or so. The showers over the east are set to ease for most by the end of the week and into the weekend with a drier airmass moving in, but it will be short lived with the humidity set to return for inland areas and across the coast and showers developing next week with local thunderstorms for inland regions. The west and most of the south should remain dry for now, there have been some hints in recent data sets that showers and storms may increase for the southeast inland but that remains to be seen.

Thunderstorm Forecast Wednesday

Thunderstorms continue for much of northeast QLD with heavy rainfall leading to flash flooding and damaging winds the main risks on Wednesday. A trough sharpening through the western interior of QLD will extend through eastern SA with a few showers and thunderstorms but moisture is limited. Thunderstorms tending more scattered over the NT and into northwest WA with storms heavy in pockets but no severe weather possible. Dry storms with a lightning risk over WA.

Thunderstorm Forecast Thursday

Thunderstorms become more scattered over the north in a monsoonal break scenario, the main forcing remaining offshore, so no severe weather expected. Gusty high based storms over interior may bring damaging winds. Thunderstorms embedded in spiral bands around a tropical low moving east over FNQ may bring areas of flash flooding.

Thunderstorm Forecast Friday

A deepening trough will take moisture from the tropics and start to see showers and thunderstorms move a little more south and southwest through the western portions of the NT into northern WA and through northwest SA and eastern WA. Some of the storms may be gusty leading to severe winds in some locations. Otherwise scattered to numerous storms over the tropics may be gusty and heavy, at this time the dynamic forcing is not there for severe weather at this time.

Tropical Depression Formation Risk - This Week - December 29th 2021 -January 5th 2022

The tropical low that is over FNQ is heading east and is likely to maintain a weak circulation as it heads east. The low may pop off the FNQ coast and this low may deepen further into the medium term. Another tropical low may form over the Indian Ocean next week.

Excessive Heat - This Week - December 29th 2021 -January 5th 2022

The excessive heat is expected to spread from west to east throughout this week with a very hot airmass lining up the eastern inland west of the divide over QLD, NSW and VIC through much of SA with a cooling trend for WA.

DATA - Refer to video for more information - GFS analysis can be found there.

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

Not much change to the pattern from yesterday which is good for forecasting purposes, the monsoon trough is now retreating north, with the westerly flow moving north over coming days away from Australia. The tropical low embedded in that flow is expected to detach and move east into the Coral Sea during Thursday with rain easing for FNQ. The south is dominated by a large high and this high is finally on the move towards the east supporting the return of warm to hot and sunny weather for large parts of the southeast. The weather in the west is becoming less hot throughout the remainder of this week but temperatures will rise next week as the new ridge pushes south of the state. That will ultimately bring a cooler change into the southeast over the weekend into next week too. The position of that next ridge is key to seeing if more rainfall does indeed develop over eastern and southeast Australia, if it ridges further south, then a more humid airmass will establish. The monsoonal flow is expected to return from the second week of January over northern Australia with further tropical lows possible.

12Z Euro - Precipitable Water Values - Next 10 Days

The PW values are below average for parts of the north at the moment which is very normal when a tropical low passes through, absorbing all that rich moisture and taking it with it as it moves from one location to another. So this results in monsoonal break conditions for a number of days before things reorganise over northern Australia. You will note the flow pattern shifts easterly up north before resuming a westerly flow pattern as the monsoon moves north and then comes south again. This will be key to introducing deeper moisture nation wide as we move through January. For the east coast, onshore winds provide humid air for today and tomorrow but then it dries out through the weekend, before moisture returns next week. Changeable airmasses for the south and southeast but with little dynamic support, little rainfall is expected at this time for most.

12Z Euro - Rainfall Accumulation - Next 10 Days

More details in the video. This model is becoming slowly wetter for northern areas.

12Z CMC - Rainfall Accumulation - Next 10 Days

More details in the video

12Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more details

12Z GFS - Rainfall Accumulation - Next 16 Days

Refer to the video for more details

12Z Euro - Rainfall Accumulation - Next 15 Days

Note that after the 10 day forecast that the models go wetter as outlined in my 6 week forecast yesterday, from the second week of January, we will be dealing with more monsoonal weather up north and deeper easterly winds and troughs in the east.

It is a fairly quiet day today so if there is anything ground breaking or major changes I will update before this evening's video - have a great Wednesday.