A very soupy airmass remains across large parts of the nation's north and east, and now travelling through the central parts of the nation once again, thanks to a trough moving into SA, dragging more moisture from the north to the south, bringing the rain and thunderstorms back to the forecast for large parts of the nation once again.
SA sits in an interesting location through the outlook period with weather systems moving through the moisture, but how far south that moisture comes, the timing of the troughs and the speed of the troughs seems to be rendering rainfall lighter for Ag areas, but northern areas of the state are expected to bring widespread falls.
For the eastern and northern areas of the nation, there is likely to be more of this humid, unsettled weather with a higher risk of flash flooding with thunderstorms, with a very rich tropical airmass in place. Thunderstorms are expected to be very productive rain producers as we have seen this week so far, so keep that in mind if you are shaded in a risk zone.
We still have model madness surrounding the large scale system emerging this time next week which means the numbers will continue to bounce around from run to run, especially over southern NSW and VIC. How far south the moisture is drawn coupled with the trajectory of that system will determine if a major rainfall event continues the wet spell.
If you are living in QLD and northern NSW, pay attention to forecasts through the weekend and into next week as there is highly amplified energetic flow pattern leading to severe weather risks for large areas of the east.
Let's take a look at the latest details.
Rainfall Next 10 Days
Rainfall remains highly volatile as based off the guidance last night in the rainfall wrap. That guidance has not changed as we move through today, so expect your number to bounce around over SA, VIC, NSW and QLD in particular for the coming 3 days. The rainfall is expected to be around today but tend back to showers and thunderstorms most of the nation on Saturday through Monday with heavy falls about leading to flash flooding. Then we have the models diverge on what happens next week, whether we see an upper low held back over WA a couple of days to make way for another upper low passing over the southeast with rain and storms in both areas mid to late week. Or whether we have the deep upper low pass through from WA into SA then QLD, NSW and VIC mid to late week bringing severe weather and heavy rainfall chances through until next weekend. One way or the other, it is going to be a very damp week across much of the nation.
Thunderstorm Forecast Friday
Thunderstorms are expected to redevelop along a trough that will move in from WA into SA later today. Thunderstorms have been active overnight through southern interior districts of WA with some of those severe. They will return again from afternoon and extend further east into SA with heavy rainfall and damaging winds the main risks. The eastern inland remains unsettled with a very humid airmass. Thunderstorms where they develop over the inland of NSW and southern QLD carry a risk of producing flash flooding and damaging wind gusts as per yesterday afternoon where there was a report of a tornado at Ganmain and heavy rainfall leading to flash flooding at Bourke.
DATA - More details in the video
GFS 12z - Surface Pressure Pattern and Rainfall - Next 16 Days
Place marking the GFS this morning as a reference point ahead of the medium term and harvest outlooks later today. The Euro is more amplified in the weather events passing through with rainfall but the GFS has more weather systems and less rainfall. In any case wet weather for many parts of the nation.
GFS 12z - Precipitable Water Anomalies - Next 10 Days
Moisture just keeps on coming.
GFS 12z - Precipitable Water Values - Next 10 Days
Excessive values for this time of year means more above average rainfall chances and below average temperatures with more cloud cover.
Euro 12z - Rainfall Accumulation - Next 10 Days
Exceptional rainfall for the eastern parts and central parts of the nation in addition to what has already fallen - with some areas heading to record rainfall values in the first week of the month over the outback. That will play out over the southeast and east in the coming 3-6 weeks.
GFS 12z - Rainfall Accumulation - Next 16 Days
There are 5 waves of low pressure in the coming 2 weeks across the nation - more details in the video. SA - do not look at that and think you are not a chance of seeing heavy rainfall - the risk is nationwide away from the far northwest. The values over the SWLD of WA is above average rainfall in the coming 2 weeks, so farmers be aware.
CFS 12z - Rainfall Accumulation - Next 6 Weeks
The exceptionally wet signal continues for large parts of the nation and I want to point out the interior near the SA/NT border continues to get wetter each run - so the wet signal may increase in December for SA, VIC, NSW and QLD. Again the tropics will be much wetter than this.
I will have your harvest outlook this morning and a detailed look at the medium term which carries higher confidence. Buckle up nationally this is going to be a wild and wet ride for many areas heading into the money making season!