The weather set to turn on Monday afternoon and evening for southern inland areas of QLD, however the heat is still on ahead of the impending cloud and patchy rainfall.
We have already experienced some of the hottest July weather on record over the weekend with temperatures in the low and middle 30s. While the temperatures are not expected to be that hot today due to more cloud and humidity in the air, the weather is warm and it will add the dynamics needed to form a cloud band.
A cold front is developing over southeastern areas, and a colder drier airmass will be moving north and east through the nation. This will set up a tight thermal gradient and support a battle ground for where showers and thunderstorms will develop this afternoon and this evening.
The thunderstorms are likely to be elevated, and carry moderate bursts of rainfall. There is a low end threat of damaging wind gusts with these storms this afternoon.
The convection that does develop will form a moderate area of rainfall, that will amplify more over NSW than QLD but still, light falls are expected to develop for southern areas of QLD with a colder shift this week.
Precipitable Water Values for the state over the coming 3 days
This will lead to rainfall developing over southern inland areas and the chance of thunderstorms during the coming 12-24hrs as well, which will deliver some isolated moderate falls. But drier air surges north from Wednesday with the southerly wind shift.
That colder drier air will move in from Wednesday which will flush the above average temperatures out back to the north where it belongs.
The rest of the week will remain seasonal and dry in the south and mostly fine but becoming humid over the north with the chance of some showers returning to coastal areas by this weekend.
Next week is still low confidence in the modelling, but there is still a bias to bringing in the westerly wind belt again this morning.
Lets look at modelling
12Z GFS Surface Pressure Pattern for the coming 16 days
Rainfall is still anticipated to be the most widespread during the next 2 days with the final wave passing over. The weather will clear the inland areas from mid week and by the end of this week most of the state should have returned back to dry and clearer with a milder northwest flow. The weather looks good for the weekend, but another wave of frontal weather is expected to bring another batch of cold fronts to southern Australia with the rainfall not as extensive as this event running over the nation, however it is over a week out and will likely change. The high pressure belt is slowly moving south over the southern states during this period and may deflect the cold fronts further south than where they have been during recent weeks. That may bring about easterly winds for QLD and upper troughs moving in may lift the moisture into more widespread showers for the east.
12z GFS Rainfall for the coming 10 days
No change from last night with the most widespread rainfall coming up today and through Wednesday for southern inland areas before it begins to clear southwards later this week ahead of a dry weekend. Then we are looking at more frontal weather developing next week through WA and SA with moisture streaming in ahead of these systems, there is a chance of further areas of rain/showers for southern NSW. But we will stay dry for now over the inland. The moisture will increase over the east coast with a trough tapping into onshore winds, but again light falls for now, but some modelling suggests widespread showers creeping west through inland areas. Something to watch.
12Z GFS Precipitable Water Values for the coming 16 days
Elevated PW values continue to surge southeast ahead of the front today with that helping to develop a cloud band with showers and thunderstorms developing. Then the PW values will come down as a dry southwest flow moves into the eastern inland. The moist air in the lower levels will persist over the inland leading to cloudy skies and light showers until about mid week and then drier and more stable air under high pressure clears the state from later this week into the weekend as the winds turn northwesterly. Another wave of tropical moisture coming from the Indian Ocean accompanies the next front passing over WA through SA next week and that needs watching if that brings another band of rainfall. Another pocket of elevated PW values over north QLD may also lead to widespread rainfall developing mid to late month if an upper trough can move into this area.
12z Euro Surface Pressure Pattern for the coming 10 days
The surface pressure pattern remains unchanged on the Euro for the coming few days, the last of the strong fronts passing through today and tomorrow bringing the most widespread rainfall and a shift to colder weather for the southeast states. The high over WA ridging in will move over much of the nation from mid to late week bringing clearance and a nice weekend of weather. Next week we have another wave of frontal weather to deal with however the frontal weather may be further south than this lot coming through this week, meaning that rainfall could be more coastal early next week. At the same time, winds may veer into the east for QLD and see showers developing for areas north of Hervey Bay as the high pressure ridge brings easterly winds back. There is some chance of an upper trough floating about with the chance of more showery weather developing under this solution, but something to watch.
12z Euro Rainfall for the coming 10 days
No change from last night, really good agreement and guidance on the rainfall over the coming 24 hours. A few spots along the ranges and the east coast will see light falls. In fact the further east you go towards the coast, most areas will stay dry. The better rainfall will develop over the northern tablelands of NSW tonight and along the border through Tuesday with moderate falls possible The rainfall then contracts back through to the south and east on Wednesday and then the weather turns dry for a while over the inland . The weather may turn showery for parts of the east coast during the weekend into next week with onshore winds developing.
12Z Euro Precipitable Water Values for the next 10 days
You can see that Indian Ocean influence in the coming 2 days with the moisture streaming across the nation northwest to southeast. That will trigger more light to moderate inland rainfall. For coastal areas, the rainfall is connected to the frontal passage this week and again next week. Another burst of moisture rushing through the jet stream early next week may produce another band of rainfall for WA and SA in around about a week or so. Note the moisture over the tropics is being intersected with drier air, but the medium term modelling shows the moisture winning out.
Rainfall for the next 10 days
Rainfall largely the next 36hrs over the southern inland of QLD before that clears by later tomorrow night. Moisture along the coast will see showers develop for the coast from later this weekend into next week, some of that could turn heavier if an upper trough floats through and lifts the moisture. A few morning showers over the NT and Cape York possible with the moisture building further as winds veer northeast. That could again come into play as we watch the upper high weaken and heights come down in the upper atmosphere supporting pop up convection.
Another look at the moisture throughout the medium term again, some very interesting weather developing mid month.