NATIONAL - 2 WEEK OUTLOOK

Well I was hoping for there to be a shift in conditions as we have been under this consistent upper level flow pattern with a vigorous westerly wind belt, zonal flow over southern parts of the nation, while in the north, ridging through mid section of the country with a strong upper high over the tropics keeping things nice and dry as well as hot!!


The pattern, looks unlikely to shift in the coming 2 weeks.


Rainfall Anomalies - 2 Weeks - Valid Thursday 22nd of July 2021.

Rainfall anomalies remain largely unchanged from the previous outlook with a drier signal for the beginning of August for the northeast parts of QLD in line with the fast flow pattern over the southern parts of the nation, keeping a dry westerly flow that is under a persistent ridge in place and an upper high to the north. Over the south, increased risk of above average rainfall thanks to the waves of low pressure embedded in the westerly wind regime. That will keep the rainfall frequent and moderate at times for the southern states.

Temperature Anomalies - 2 Weeks - Valid Thursday 22nd of July 2021.

Temperature anomalies for the coming 2 weeks also largely unchanged with the weather dominated by the westerly wind regime, sending up pulses of very cold wintry weather but then seeing brief warm spells offsetting the cold snaps in between systems, so there will be variability in temperatures over southern parts of the nation. Over the northern half of the nation, no change, above average temperatures are expected to continue thanks to the upper high.

Expected Rainfall - 2 weeks - Valid Thursday 22nd of July 2021.

The expected rainfall is likely to favour southern areas of the nation once again during the coming 2 weeks with most of QLD, and the NT dry and warm to hot. The pattern may break down just outside of this period. That is in line with the longer term climate modelling which suggests weather will turn wetter as we go through August for QLD. The rainfall remaining above average or at least average for large parts of the southwest, south and southeast.


DATA SETS


18z GFS - Upper level flow pattern at 18000ft - Valid Thursday 22nd of July 2021.

You can see the medium term modelling suggests this westerly wind regime is not going anywhere and with the SAM suggesting that the southern ocean remains in a slightly negative phase over the course of the 2 week period ahead, that will see more frontal weather pass over southern Australia, but not penetrate much further north. Ridging and upper highs over the tropics will lead to sunny dry and hot weather.

18z GFS - Surface Pressure Pattern and Rainfall Distribution - Valid Thursday 22nd of July 2021.

The westerly wind belt continues to hold multiple fronts through southern Australia with very little getting further north than southern NSW for the east. The weather looks to persist into the first week of August. Maybe, just maybe the change comes just outside of this medium term forecast, but I think it will be the second half of August, for those inland, to see a rainfall event that does develop from the northwest. Otherwise the westerly wind belt continues to drive the temperature and rainfall prognostics. The Indian Ocean is continuing to warm and will come into play quite suddenly, so looking for that signal from the models in the coming week.

18z GFS -Rainfall anomalies for the coming 2 weeks - Valid Thursday 22nd of July 2021.

The drier signal continues for a lot of inland Australia, the wetter and atleast wet signal continues for the southern coastline. Dry seasonal weather over the north and northwest. But the eastern inland looks drier. However this model has been running a little too dry for inland areas but it is picking the spread of rainfall connected to the westerly wind belt.

12z CMC- Rainfall for the next 10 days - Valid Thursday 22nd of July 2021.

Similar spread to the GFS which shows the westerly wind belt and actually factors in the moisture profile for the end of next week which comes through WA and into SA and southeast Australia later in the period into early August. The north is seasonal, QLD drier than normal for the next 10-16 days.

12z Euro - Rainfall Anomalies next 2 weeks - Valid Thursday 22nd of July 2021.

This is probably closest to the truth with the current synoptic pattern. There is every chance inland areas could see moisture shoot through the inland areas of SA and WA bringing areas of rain from time to time, as the weather is not exactly clear cut in this region being dry at this time. Dry weather for QLD and the NT will continue and along the NSW coast in the westerly wind regime. The wetter weather continues for the south of the nation.

12z CMC- Temperature Anomalies next 10 days - Valid Thursday 22nd of July 2021.

The warmer signal continues for the north and northwest, curiously this model suggest cooler weather for parts of southern QLD, not too sure on that. But otherwise near normal conditions overall for the southern parts of the nation, but bitterly cold weather this weekend over the southeast will be offset by a rapid warming trend early next week as winds turn northwesterly. That pattern continues for about 2 weeks.

12z Euro - Temperature Anomalies next 2 weeks - Valid Thursday 22nd of July 2021.

This is probably closest to the truth based upon all the data today, the warmer sigal continues for the northern parts of the nation spreading throughout with broadcast northwest winds. Then frontal weather riding up from the south will clip the southeast coastal areas and mitigate the above average temperatures. The above average temperatures a direct result to the elevated SSTs off the northwest coast of Australia.

12z GFS - Temperature Anomalies next 2 weeks - Valid Thursday 22nd of July 2021.

Very similar spread to Euro and this is a good forecast for the coming 2 weeks. Widespread above average temperatures for the period likely over the northern two thirds with coastal areas experiencing the frontal weather which will keep temperatures overall near seasonal, but there will be dramatic drops in temperatures and increases in temperatures ahead of frontal weather.

So I wish I had better news for those in QLD and inland areas of SA that need a lot more rainfall, but it will come. We just need the pattern to break down. I will have a look at the Indian Ocean again for the coming 2 weeks tomorrow to see if there are any surges of moisture heading our way.


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