NATIONAL WEATHER PICTURE - PM EDITION - WEDNESDAY 30TH OF JUNE 2021

Headlines


  • Significant cloud cover developing through the eastern inland after heavy rainfall about parts of the east coast overnight with showers breaking out along a trough that is lined up through inland QLD south through inland NSW. Storms are possible across this trough over the coming days.

  • Showers have eased over parts of the east coast with the flow tending more northeasterly clearing southern NSW but more showers are expected to develop later this week with locally heavy falls with the trough approaching from the west over the Wide Bay down through to the Northern Rivers.

  • Settled over the southern parts of Australia with a front diving away to the south. It has become windy and those winds keeping the temperatures up tonight. A stronger cold front will emerge during Thursday afternoon on the satellite and that is to bring a colder shift Friday with rain developing for the southeast.

  • Warmer over the north and northwest with conditions also dry and mild over WA with a new ridge of high pressure.


National Satellite Imagery - Valid

Cloud has continued to increase over large parts of the inland in line with modelling now showers are breaking out with the risk of thunder tonight and persisting into Thursday. The cold front coming through SA is weakening and producing cloud and wind as the main elements. A stronger cold front can be seen surging through the Bight, a follow up front will emerge on Thursday moving northeast. Moisture still evident through the inland of WA but there is no trigger.

This is the area of significant interest for the eastern inland with a deepening trough now tapping into a deeper moisture supply driving patchy rainfall and a thunderstorm threat overnight tonight, with that activity expected to increase during Thursday and Friday, before contracting east on Saturday. The latest break down below this.

Temperatures - Valid Wednesday 30th of June 2021.

Mild through much of Australia with elevated moisture levels streaming through the north and east. That has kept temperatures up overnight and today. More seasonal back through the southwest. Canberra 16C this afternoon and 32C at Normanton is above average temperatures for this time of year.

Spot where it is raining!! 14C at Thargomindah but go out to the northeast and it is sitting pretty in the mid 20s and partly cloudy skies. Certainly not a one number place. A mild night tonight is on the way with above average temperatures.

Radar - Valid Wednesday 30th of June 2021.

After a showery night along the coast, the airflow tending northeasterly is now keeping the showers parallel to the coast in NSW. Showers are more scattered over the northern coasts and into QLD today. Patchy rainfall through Yarrawonga extending north up to Thargomindah and Boulia in QLD but no radar coverage so cannot tell how much is falling, but observed rainfall is about 1-3mm over inland NSW into northeast VIC.

Rainfall for the next 10 days - Wednesday 30th of June 2021.

Rainfall chances increasing over the west now with more frontal weather coming into the picture next week. Rainfall largely unchanged over the east and southeast. Can we fill the gap in between and see better rainfall for SA soon?

GFS 00z run Rainfall next 10 days - Valid Wednesday 30th of June 2021.

Rainfall continues to look very promising for what is the driest month of the year for QLD and northern NSW. Rainfall with the trough is extending south a little more tonight. Cold air with showers, could now bring some moderate falls to southeast SA and southwest VIC. The wettest part of the country from next week will be the west coast.

CMC 00z run Rainfall next 10 days - Valid Wednesday 30th of June 2021.

Very similar spread to GFS with widespread rainfall for the east, it has also brought that lead rainfall with the trough a bit further south in the evening run. Showers with a cold airmass over the southeast this weekend. And then the west, looking wet and widespread moisture coming southeast through the jet stream next week also.

Euro 00z run Rainfall next 10 days - Valid Wednesday 30th of June 2021.

The latest Euro has heavier rainfall back through central inland as the trough looks to stall out Friday and Saturday with the blocking pattern over the Tasman. Heavy falls possible in random scattered pockets through inland NSW back towards the Upper Western. But they will be random and scattered. Rain increasing over WA and note the moisture improving over the southern interior of WA. Moderate rainfall for southeast SA and southwest VIC with the low pressure system later this week with follow up rainfall later next week.


Model discussion and analysis.


GFS 00z run - 500mb/18000ft flow pattern above our heads Wednesday 30th of June 2021.

GFS 00z run - Surface pressure pattern and rainfall distribution Wednesday 30th of June 2021.


Thursday 1st of July 2021

Large upper high over NZ beginning to slow down and become stationary. A trough moving through QLD and NSW causing unsettled weather. A strong long wave south of the nation beginning to move northeast with a cold airmass to drive north. New ridge over WA keeping things dry and dry over the NT.

Showers increasing to areas of rainfall through inland QLD. Scattered thunderstorms are possible. Showers along the east coast, heavy at times through the Gold Coast and Northern Rivers. A strong cold front approaching the southern coastline with a gusty northwest wind developing later, showers likely over the southern coastline of WA with that front but falls light. Showers between Cairns and Cardwell continuing but easing in intensity. Fine elsewhere.

Friday 2nd of July 2021

Strong upper trough over the southeast with a cold airmass to follow sweeping through the region during the day. Strong upper high over NZ continuing to remain stationary. Trough over QLD and NSW as a consequence slow moving with the high ridging back towards Australia. Upper heights coming down over inland Australia. New ridge over in the west continuing to extend east.

Strong cold front passing through the southeast bringing a band of rain and colder weather with a wintry mess moving east. Rain and storms over NSW moving through to the east and persisting through QLD with scattered afternoon storms with moderate to heavy falls. High pressure over the southwest with settled conditions, though a cold morning for inland areas. Fine over the north though humidity levels still high over Cape York.

Saturday 3rd of July 2021

Upper low forms on a slow moving wintry blast over the southeast, that is thanks to a retrograding high pressure zone over NZ causing a block through the region. Trough in between over QLD and NSW may kick off another round of thunderstorms with moderate to heavy falls before leaving the coast. Upper ridge over WA moving east slowly. Heights remain below average over much of the north with broad troughing.

Rain and storms continues from the Capricornia and Coalfields into the southeast with moderate to heavy falls along a trough that remains slow moving. A strong cold front rotating through VIC collapses with a low bringing strong and gusty cold winds to the region, the bulk of the showers through southeast SA and western VIC with this feature. Dry air and subsidence between the trough to the east and the cold air to the west keeping much of NSW dry. Fine over WA with warmer weather.

Sunday 4th of July 2021

Upper high continues to strengthen over NZ with heights well and truly maxing out over the region with above average temperatures for NZ. Slow moving upper trough over the southeast weakening as a consequence while it moves east taking the surface trough offshore QLD. Weakening ridge over WA ahead of a long wave trough that approaches the southwest later Sunday.

Rain and storms slowly clearing from the east coast with a trough leaving the region, held up by a strong high over NZ. Showers and strong winds for southern VIC and TAS with a low weakening over the southeast during the day. High pressure moving over SA slowly moving east. On the western flank of that high, windy and mild to warm ahead of a front bringing rain to the west late in the day. A chance of moderate to heavy falls with that front.

Monday 5th of July 2021

Upper trough over the southeast continues to do weird things in the modelling - this is low confidence forecast period now. Upper high over NZ remains strong and parked over the country. Strong long wave trough over the west should bring more rain and strong winds to southwest WA. A weak ridge over SA maintaining settled weather for northern and central Australia.

Cold air over the southeast perhaps bringing some afternoon showers in an unstable airmass but this is low confidence forecasting. This will likely change. The east likely to stay dry after the trough clears offshore. The wettest part of the nation will be the southwest with a series of fronts rotating around a deep low offshore to the southwest bringing cold and wintry weather. Fine and seasonal over the north with lower humidity.

Tuesday 6th of July 2021

Upper high over NZ finally moving away with the upper trough exiting the east coast, but most likely will be gone by then. Zonal flow over much of the nation with a fast flow pattern developing in response to the westerly winds contracting north from the south. Weak ridge over the southeast keeping things drier. Strong long wave persists over the southwest with cold wintry weather.

Windy with showers and small hail through the southwest, making this the focus of wet weather next week as high pressure takes over the east. The centre of high over NSW leading to cold nights and sunny days. Winds freshening through SA with a warmer flow moves through from the northwest. Seasonal through much of the nation away from the southwest third.

Wednesday 7th of July 2021

Strong long wave persisting over the southwest with wintry weather continuing. Ridging over the east beginning to move east, with a fast flow zonal flow developing with waves emerging in that flow pattern. Very winter like.

High pressure over the southeast steadily moving towards the Tasman, that will make room for the first of a series of fronts. The first front bringing strong and gusty northwest winds and a little late rainfall to the southeast. Another front moving through western SA bringing showers later and another front southwest of WA bringing another burst of showers. Fine elsewhere and seasonal.

Saturday 10th of July 2021.

Fast flow pattern continues through Australia with a ridge parked north over QLD. Classic winter time pattern with multiple waves passing through the flow pattern.

Windy with showery periods over southern Australia with light to moderate rainfall. Inland rainfall possible with some of these fronts as the pass through at pace. A weak high over the interior will move through these regions while the frontal weather persists for southern Australia. Typical weather for July.

Comparing the Euro for the east coast rainfall and cold outbreak events with GFS tonight.


Easier to look at the flow patterns from both. So this is the surface pattern with rainfall from GFS and then Euro underneath.


Starting to come into agreement as the weather systems responsible get analysed in real time by the upper air network and then feed back into the models.


GFS 00z run - Surface pressure pattern and rainfall distribution 6hrly - Valid Wednesday 30th of June 2021.

Euro 00z run - Surface pressure pattern and rainfall distribution 6hrly - Valid Wednesday 30th of June 2021.

More details on the rainfall event for the east and southeast coming up later this evening with an update on the west coast rainfall event as well.


Need more weather information - email me at karllijnders@weathermatters.org for more.

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