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

Headlines


  • Showers increasing over the eastern seaboard as onshore winds increase.

  • The latest on the developing rain event for the eastern inland

  • The latest on the cold outbreak developing for southeastern Australia.

  • Details on the rainfall set to sweep the southwest later in the weekend.

But we are looking at dry weather for many areas too, including large parts of inland SA, WA and the NT with high pressure dominating. There will be an increase in rainfall chances for SA and WA next week.


Showers have become more frequent over the eastern seaboard with an easterly flow establishing on the top of high pressure moving to near Canberra today. The showers will extend a little further inland but the biggest impact will be the moisture that surges inland over the next 36hrs, feeding a trough over western QLD and NSW.


A cold outbreak still on the models for later Friday into the weekend, this system again changing from overnight data and the latest details below. It will impact the performance of the rainfall event over eastern QLD and NSW Friday and Saturday.


There is that large event still being picked up for later in the weekend with a long wave trough to increase rainfall over the region with a strong and gusty wind developing. Before then, nice and settled for WA under high pressure.


National Satellite Imagery - Valid Wednesday 30th of June 2021

Cold front passing through the Great Australian Bight starting to weaken as it approaches the southeast but is likely to bring a windy day to the region. Low cloud and onshore winds providing showers for the east coast. Cloud increasing over the eastern inland this morning with some light rainfall.

Onshore winds bringing cloud and those showers as expected to the east coast with some moderate falls about the Gold Coast this morning. The moisture is streaming through to inland areas producing cloud and some light rain this morning in some locations with the rainfall coverage expected to continue this morning.

Temperatures - Valid Wednesday 30th of June 2021

A milder morning across the nation with pockets of above average overnight temperatures with troughs and moisture about the east keeping temperatures up and a moisture plume over the northwest keeping things sticky about the far northwest. Colder back through the southwest as high pressure raced in and cleared skies from the inland.

Cool through the southeast this morning but you can see the impact of that easterly moisture and the trough over southwest QLD and into northern NSW with elevated temperatures. In fact it is a much warmer morning across the region.

Radar - Valid Wednesday 30th of June 2021

Showers about the east coast becoming heavy at times near the coastal fringe. A few light showers making it inland. 10-20mm has been observed over the coastal parts of NSW and into southeast QLD with isolated heavy falls exceeding this.

The moisture has made it inland with a few showers developing. Only light falls but the coverage of rainfall will increase throughout the next day or two with the trough deepening and moisture also increasing.

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

Rainfall still moving around with the low confidence surrounding the cold outbreak over the southeast continuing to cause headaches pinning down rainfall totals for the southeast and parts of the eastern inland. Expecting half a months worth of rain at least for QLD and NSW with many seeing more. Rain increasing for southwest areas of the nation from Sunday.

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

Rainfall still erratic from run to run, the rainfall more thundery over the east meaning the even distribution of rainfall is not visible on this chart for the eastern inland. There is another system later next week for the southeast. A series of strong cold fronts bringing widespread rainfall to the southwest with moisture streaming in from the Indian Ocean.

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

CMC has finally come to it's senses and sees the rainfall over QLD and NSW but has it further east and the southeast cold outbreak much weaker. Also can't see the rainfall over the west coast from Sunday. So this is still an outlier.

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

The model is now starting to get the rainfall shield and spread more consistent from run to run, it is now a matter of where the heavy rainfall sets up along the coast with convergence this Friday and Saturday. Extensive rainfall for the northern inland of NSW. Another system still being analaysed for next week but the rainfall not as aggressive for inland areas of southern and eastern Australia in this run. But the moisture is increasing off WA each run.

Model discussion and analysis.


GFS 00z run - 500mb/18000ft flow pattern above our heads

GFS 00z run - Surface pressure pattern and rainfall distribution


Wednesday 30th of June 2021

Strong upper high over NZ with stable weather extending back through to the east coast. A developing surface trough deepening today with an upper trough moving in from the west this afternoon. A flat ridge over in WA continuing to ridge east. A wave passing into the Bight weakening as it heads further southeast.

Scattered showers along the coast with a northeast to easterly flow. That moisture likely to surge inland and that will meet the trough, showers increasing this afternoon along that trough with the chance of thunder. Showers may even develop through inland NSW as well now with a humid airmass. Fine weather back over northern and west Australia with a high taking control.

Thursday 1st of July 2021

Strong upper high remaining slow moving over the southeast with a ridge extending back into the southeast. Strong long wave over the Bight bringing a wintry surge into the Bight. Troughs deepening over the eastern inland as they track towards a deeper moisture profile further east. A flat ridge over the southwest with a zonal flow over the nation.

Showers turning to areas of rain through northern NSW and into southern QLD. Some light rain possible about the southern inland of NSW extending to the divide. Some moderate to heavy falls possible about southern inland QLD and northern inland NSW with thunderstorms. Showers continue about the east coast with moderate to heavy falls in onshore winds. A strong cold front approaching the southeast with a gusty northwest wind and cloud increasing later in the day. Fine elsewhere with high pressure

Friday 2nd of July 2021

Strong upper trough moving into the southeast with a cold wintry blast extending to the southeast inland late in the day. Upper high slow moving over NZ with a ridge extending back to the east coast. Trough over inland QLD and NSW moving eastwards, propelled by the long wave coming into the southeast. Flat ridge over the southwest with settled weather. Heights about normal over the north.

Showers increasing over the southeast with a cold and wintry airmass following a strong front. Showers and storms over the east coast, turning to areas of rain over central and eastern QLD with moderate to heavy falls but clearing through NSW quicker in this run. High pressure back over WA with settled weather over that region. The rainfall distribution in the east is still a low confidence forecast.

Saturday 3rd of July 2021

Upper low over the southeast becoming slow moving due to a strong upper high parked over NZ. Trough moving towards the east through QLD and northern NSW. Upper trough hangs back through the central interior but largely inactive. Ridging over WA breaking down with the approach of the next long wave.

Rain with moderate to heavy falls continuing over eastern QLD with the rain easing from the west and clearing off the coast at night. Showers clearing offshore the NSW coast by afternoon. Showers with small hail and thunder over southern VIC and western Tasmania with a gusty low pressure system. High pressure slowly moving east, clearing out large parts of coastal SA by afternoon, and bringing a warmer northerly flow over the west coast with sunny skies.

Sunday 4th of July 2021

Upper trough over the southeast weakening and heading to the southeast. Trough lifting off the east coast. Upper high still parked over NZ blocking the Tasman Sea. Strong long wave approaching the west coast with a windy and wintry blast developing by afternoon. Fine weather over the north of Australia under a flat ridge.

Rain and storms clear off the east coast early Sunday. The low over the southeast is weaker in this run so clearing quicker through the southeast but again this may change. Strong low and cold front approaching the southwest of WA with rain and storms, may extend up the west coast with a moisture in feed bringing in heavy falls to the region. Rain extends inland later in the day. Fine elsewhere.

Monday 5th of July 2021

Strong upper trough passing through the southeast with a very cold airmass in the region. Upper low forms on the south coast of NSW but again low confidence in this element as the model has not shown this before. The upper high continues over NZ and that is the dominant and more likely feature to appear in reality given the consistency of it being there in previous data sets. A zonal flow through the nation.

Widespread rain and storms through the southwest, but the rain band from overnight into Monday collapses through the inland in this run, leaving inland areas with light rainfall totals at this stage. But cold and wintry weather for coastal areas keeps the moderate rainfall going. Maybe showers over the east coast under an upper low and southerly winds but I am not convinced of this. Fine elsewhere after cold starts with frost over the eastern and southern inland.

Tuesday 6th of July 2021

Upper trough passing through the southern coastal areas of WA with strong frontal weather moving into the Bight. A zonal flow over the nation continues to keep the weather seasonal. Upper high over NZ continues to be slow moving extending a ridge back through to northern Australia.

High pressure over the eastern inland moving east at speed due to the upper winds moving the system from west to east more freely. Showers about southwest parts of the nation with a gusty flow thanks to a low to the southeast. A weakening front bringing cloud and strong winds to the southeast and southern coastal areas, but no rainfall at this time. Temperatures likely to be above average over the southeast. More humid over the north of the nation.

Friday 9th of July 2021.

Strong upper trough over the Bight moving east, with weak ridging over the west and an upper high over the Coral Sea extending a ridge south down the east coast. This is a traditional winter pattern for July.

Showers over the southern coastline spreading into the east with hints of moisture feeding into this front with areas of rainfall over inland areas. But otherwise it is more likely we will see a fast flow pattern across southern Australia with fine weather over the north. But as always this is 10 days out, this will change.


Lets compare with the Euro for the east coast rainfall event and the southeast cold outbreak to see if there are similarities.


Friday 1st of July 2021

Upper trough in a similar position over eastern QLD and the cold outbreak with the upper trough over the southeast also in a similar position to the GFS run this morning meaning there is better agreement on timing on the movement of systems this morning.

Rain and storms over the eastern inland heavy at times with thunderstorms, extending into northeast NSW with a cold airmass over the southeast bringing showers and small hail to SE SA, Victoria and parts of southern NSW. The rainfall is not as extensive over inland NSW with this run.

Saturday 2nd of July 2021

Upper trough over the eastern inland moving east and an upper low over the south and southeast bringing cold and wintry weather to the region, but note that this morning, this feature is further south. Yesterday this time, the model had a low sitting over Canberra. So still low confidence in placement of this system.

Rain and storms through QLD, with moderate to heavy falls, but moving out quicker like GFS so rainfall numbers may need to be scaled back over inland NSW but will wait for this afternoon to see if there is merit to this. Showers and cold weather over the southeast with a low in Bass Strait but the airmass is relatively dry so moderate falls for coastal areas.

Sunday 3rd of July 2021

Upper trough weakens over the southeast with the weather clearing east over the southeast. Fine weather returns into SA and western VIC. Trough over QLD beginning to move eastwards.

Front and cold weather clears the east coast with a high moving in. The focus of the wet weather moves into thee west with a deep low offshore the southwest. That is similar to GFS.

Need more weather information? Email me at karllijnders@weathermatters.org for tailored forecasting solutions.


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