MORNING WEATHER UPDATE - THE DRY SPELL BEGINS FOR MUCH OF THE NATION

Given the quiet weather pattern at the moment (first time in about 10 weeks!) it means I can focus on streamlining the information and do more medium to long term climate posts this week.


That means until there is more dramatic weather appearing, I will do the state updates once a day until conditions shift with your updated rainfall charts (very little to draw at the moment).


Lets get to the weather update below

Rainfall for the next 10 days

There are some indications that rainfall will return to inland areas of QLD and NSW, which I will draw in following the next 2 lots of data sets, I just want to see more consistency. The higher chances of rainfall will be over the southwest and the southeast of the nation with that weaker cloud band running through the westerly winds under the high pressure.

Temperature Anomalies next 7 days

Temperature Anomalies following 7 days

Rainfall Anomalies next 2 weeks

A drier trend for much of the nation is seasonal, slightly bias to drier than normal for the south and east, but really, not uncommon after such a large rainfall event over the nation, it just hurts areas that missed out in the rainfall event which is SA and southeast QLD/northeast NSW.

THE DATA


12Z GFS Surface Pressure Pattern for the coming 16 days

The pattern settled for the coming 7 days nationally, we do have one system coming through the southwest which will bring a chance of showers/rain through the SWLD and that cloud band extends back through to the southeast. Weak troughs and fronts bringing light falls at times over VIC and heavier falls over TAS, but limited to coastal areas. Classic spring weather. Then we see the inland become more unstable over SA and then eastern QLD and NSW which could see showers and storms return to the forecast next week which will be the focus of the medium term forecast later today.


12z GFS Rainfall for the coming 16 days

Rainfall limited to coastal areas with fronts and a narrow sliver of moisture coming through the westerly winds. Then the inland areas start to see showers and storms break out from SA, through inland NSW and QLD. Moisture over the northern parts of the nation could play a part in this, with showers and storms developing for the NT once again as the build up continues to evolve.

12z GFS Precipitable Water Anomalies next 16 days

Note the drier air coming through the nation over the coming 5-7 days in the wake of this large scale system lifting offshore. The west will start to see the next impulse of moisture later Wednesday and that could bring areas of rainfall mainly south of Perth mid to late this week. Then that moisture flies through the westerly wind regime over TAS and VIC later this week with light to moderate rainfall. Moisture then comes back this weekend over the north and east with rainfall chances increasing from mid month onwards with persistent easterly winds. You can see by the end of the run, the drier air has been overrun and shoved back to the deserts of WA where it should be.

12z Euro Surface Pressure Pattern for the coming 10 days

The pressure pattern is fairly similar to the GFS for this week. They do agree on placement of the high pressure system over the course of the next 7 days with weak systems undercutting the high over southern coastal areas of the nation while the inland remains dry. The models then support the weather turning unstable next week as heat values and humidity levels increase over the northern tropics. This then gets drawn south as easterly winds begins to dominate bringing rainfall chances back to inland areas near troughs, which could kick off showers and thunderstorms.

12z Euro Rainfall for the coming 10 days

Lean rainfall totals over inland areas but coastal areas could see follow up rainfall through the southeast areas. Rainfall comes to southwest areas mid to late week with heavy falls possible there. Showers increasing for FNQ with onshore winds freshening. Showers and storms redeveloping over the Top End from the weekend into next week with moderate falls in thunderstorms. Then all that moisture starts to seep southwards into troughs moving through the southern and eastern inland. That could kick off the next lot of rainfall for SA and through NSW/QLD.

12z Euro Precipitable Water Values next 10 days

Moisture values below average this week with high pressure in full control. The weather will be largely dry until about the early parts of next week for inland areas, that is where we see moisture return with showers and thunderstorms popping up. In the short term, the narrow strip of moisture coming through the westerly wind belt will hook up with frontal weather passing over producing bursts of rainfall for the southwest and southeast while the remainder of the nation is dry. Up north, moisture will begin to increase this weekend with showers and thunderstorms redeveloping.

NOTES

Rainfall Percentages Month to Date

5 days in and many areas over the inland of the nation have recorded near record rainfall for September, through QLD and the NT, and some decent falls for NSW and VIC through the northeast of SA as well. But the band of rainfall as expected fell apart on approach to the east coast. So we can see which areas need a drink in the coming week.

I will have my Medium term forecast and a detailed look at the moisture in play on the latest guidance plus a look at the Indian Ocean as well over the coming 2 weeks to see if we will see any influence from that given that the model data is saying the negative phase is expected to strengthen from now!