NATIONAL WEATHER PICTURE - AM EDITION - TUESDAY 29TH OF JUNE 2021

Headlines


  • Showers moving through the southwest with a cold airmass. That front breaks down heading eastwards.

  • Cold morning over the east with heavy fog but sunshine and milder weather to follow

  • Showers developing for the east coast with onshore winds.

  • That feeds a trough over the eastern inland later with widespread rainfall developing.

A cold front has crossed through southern WA overnight bringing widespread showers and strong winds throughout the course of this evening. Some showers have been heavy with small hail and thunder about the south coast. The coldest of the air is now moving into the open waters of the Bight as the front begins to weaken as it heads through to the east. Showers in the west to southwest winds will continue. It will be brisk.


Cold morning over the east under settled high pressure. The high continuing to control much of the mainland's weather as it meanders along to the east continuing the run of cold nights and sunny days for much of the inland.


The same high is also the cause for showers to return to the east coast with an onshore wind flow rotating around the centre of circulation. This will continue to deepen a little and more showers can be expected from Cape York through to Sydney.


The moisture will then feed a low pressure trough over western NSW and QLD with that activity expected to become more widespread as we track through Wednesday night into Thursday, organised areas of rain and a few storms breaking out Thursday and Friday for large parts of eastern QLD and NSW.


National Satellite Picture - Valid Tuesday 29th of June 2021

Satellite largely clear this morning over the southern and eastern inland with high pressure overhead bringing a cold and foggy start for many locations. Clear over the north with seasonal weather. Cloud over southwest WA is the cold front moving through the SWLD this morning with moderate rainfall and a storm or two. Showers developing along the NSW coast with low cloud increasing.

Showers increasing along a cold front that is moving through this morning with a gusty southwest to westerly change. Low cloud along the coast north of the front producing isolated showers. Clear over much of the inland with lighter winds.

Low cloud in onshore winds producing showers along the NSW coast this morning, becoming more scattered this afternoon as the winds turn more easterly. Showers could produce moderate falls along the coastal fringe with lighter falls getting inland towards the Great Dividing Range.

Temperatures - Valid 6am EST Tuesday 29th of June 2021

Cool start through the south and east under the dominance of high pressure with light winds and clear skies. Milder over the north and northwest with a bit more cloud and stronger southeast winds. Mild through southern and eastern WA with a stronger northwest wind. But the cold start over the southeast is near seasonal for this time of year.

Seasonal start to the day over the southeast with some frost about, but it is more about the fog with locations across the inland reporting visibility down below 50m. This fog may take a while to lift with high pressure overhead and the light winds struggling to mix out the fog.

Radar - Valid 6am EST Tuesday 29th of June 2021

Showers have started to develop along the coast this morning, these may be sharp at times on the coast but as the roll over land will weaken and if you are living 50km inland, dry weather is likely to continue. Up to 10mm across the coast in some locations.

Cold front moving through southwest WA bringing a band of gusty showers with moderate falls about the SWLD. The rainfall will be much lighter and patchier the further inland you travel today, the showers likely to ease later today along the coast. Some hail and thunder possible over the South Coast.

Rainfall for the next 10 days - Valid Tuesday morning 29th of June 2021

Rainfall increasing over the eastern inland during the latter part of the week, this will likely be the biggest event for the week still. Showers over the southwest of the nation today easing later in the day and clearing later Wednesday ahead of another wave of fronts over the southwest later in the weekend. Showers increasing over the southeast with a strong front and cold pool moving in across the weekend. Dry over the inland with high pressure.

GFS 12z run - Rainfall for the next 10 days - Valid Tuesday 29th of June 2021

Rainfall still widespread on the GFS guide this morning for the east but is broadening the moderate rainfall potential through much of the east, but the heavier falls are offshore but again likely to change. Showery through the southeast with a cold front and low but again that system not as dynamic this morning meaning the inland trough is not as robust. Showery through the southwest today and note the moisture pooling over the Indian Ocean.

CMC 12z run - Rainfall for the next 10 days - Valid Tuesday 29th of June 2021

Off with the fairies still....but is picking up on the heavier rainfall being the further east you are through QLD which is a fair assessment based on the synoptic flow.

Euro 12z run - Rainfall for the next 10 days - Valid Tuesday 29th of June 2021

Widespread rainfall largely unchanged in the spread this morning with heavier falls developing now as far north as the Capricornia and the Coalfields which would be welcome. Rainfall along the coastal areas with cold fronts pushing through the southwest this morning, the southeast later this week and then back across the southwest later this weekend. Again deep moisture sitting over the Indian Ocean is likely to be drawn in across the mainland after this period, if not at the end of the run, but that is still low confidence.

KMA 12z run - Rainfall for the next 9 days - Valid Tuesday 29th of June 2021

Not as aggressive as previous runs, but is liking the rainfall for QLD and over much of the west coast too with the weekend event, so more on that later on today, when the runs come through at 18z to see how that verifies.


Model Discussion and Analysis

GFS 12z run - 500mb/18000ft flow pattern - Valid Tuesday 29th of June 2021

GFS 12z run - Surface Pressure Pattern - Valid Tuesday 29th of June 2021


Tuesday 29th of June 2021

Strong upper high over the east keeping things calm and settled, rinse and repeat weather over the eastern parts of the nation today. Long wave passing through southwest parts of the nation with a front moving over the region. Upper high over the north of the nation keeping daytimes slightly above normal temperature wise but the dry continuing.

High pressure over the southeast with onshore winds rotating through the east coast with showers increasing for coastal communities. Little rainfall moving inland however moisture will move inland today. Note the kink in the isobars over western QLD, the surface trough developing there is inactive with a dry airmass today. A front passing through the southwest of the nation producing showers and small hail this morning with easing conditions along the west coast this afternoon. Fine elsewhere.

Wednesday 30th of June 2021

Upper high over the Tasman moving slowly east. Upper trough deepening a surface trough over QLD to produce unsettled weather with moisture arriving from the east. A weakening front approaching the southeast with a new ridge pushing into the southwest. Under that a strong cold front moving northeast from the Southern Ocean.

Showers breaking out over inland QLD and NSW with a thunderstorm possible. Onshore winds producing widespread showers along the east coast, some could be heavy as the flow tends northeasterly. Showers easing over the QLD coast during the morning. A weak front approaching southeast SA later with light showers. Fine elsewhere with that strong cold front starting to appear over Bight later.

Thursday 1st of July 2021

Strong long wave moving through the Bight bringing colder air to the southern coast of SA later in the day. Trough deepening over the western inland of QLD and northern NSW. Upper high holding firm over NZ and strengthening further. A new upper high over southwest WA moving eastwards . Weak trough over inland parts of the nation inactive for now and heights over the NT coming down with a reduction in heat levels.

Widespread showers over inland QLD and NSW with a few storms, this run a little thinner in rainfall coverage, but still damp. Showers continuing for the east coast with moderate falls over northern NSW and southeast QLD. A front approaching the southeast bringing gusty winds and late rainfall for southern SA and western VIC. Mild ahead of the front over the southeast inland. Dry elsewhere with a large scale ridge controlling weather. Humidity increasing over the north but reserved for Cape York.

Friday 2nd of July 2021

Strong long wave weakening a little and slowing down over the southeast with an upper high stationary over NZ. A large broad upper trough over the interior helping to provide unsettled weather for inland QLD and NSW. Upper ridge moving in over WA extending itself through to the Bight. Heights near normal over the Tropics.

Widespread showers developing over the southeast with a very cold airmass moving into the southeast inland. That air is dry so the precipitation will be what you would expect from a cold outbreak, showery through the coastal areas with hail and thunder with dribs and drabs coming over the divide for inland areas with light falls generally. Rain and a few storms over inland QLD and NSW moving east, but note that there is no low pressure developing as per last night on this run, meaning the rainfall rates for the eastern inland event is less. But this will change - low confidence forecast applies

Saturday 3rd of July 2021

Upper low over the southeast with a cold airmass. A trough over the eastern inland moving slowly eastwards with the upper low. Upper high over NZ, at 576, very strong and the dominating force for a large portion of NZ and eastern Australia, blocking up the passage of the upper systems over eastern Australia. Upper high over the west moving east towards SA with a long wave behind that system off the west coast.

Widespread rain with a slow moving trough over QLD with moderate to heavy falls from the Coalfields through to the southeast of QLD. Showers increasing over the southeast with an upper low, producing local hail and thunder for the region and snowfalls down to lower than 1000m. Some light snow possible for southeast NSW and the ACT if the moisture is sufficient. High pressure over the Bight moving eastwards with a northerly flow warming WA but cold onshore winds for SA. Fine and dry over the northern parts of the nation.

Sunday 4th of July 2021

The low confidence forecast continues, the upper low that was analysed last night being west of TAS is now east of TAS, totally shifting the weather impacts. So this will likely change. But overall the current guide from this model has the upper high still strengthening over NZ and a ridge extending north through to the Coral Sea. This is keeping the trough and low slow moving over the east. New strong upper trough over the southwest with a new cold front pushing through bringing wintry weather. A weakening high over SA bringing settled weather for much of the inland.

Rain and storms leaving the east coast during Sunday with colder southeast winds to follow. Clearing over the southeast with a weak high moving in and shunted the low to the southeast. A large front with moisture impulse bringing rain and storms to the west coast with a very cold airmass developing for the SWLD later. Fine and dry elsewhere with dry air moving in.

Monday 5th of July 2021

Large long wave over WA bringing a wintry period of weather and possibly severe weather. Upper high over NZ continuing and a weak upper low over the Tasman. New ridge over the eastern inland clearing the south and east with cold nights and sunny weather to follow. The main weather action returns to the west coast early next week if this is right.

Rain and storms through the southwest of the nation with a cold airmass. Severe weather is possible with this feature with damaging winds. Moisture still being injected into the Pilbara and Gascoyne is possible through this period, so that is an element I will be watching if this indeed verifies. High pressure in the east keeping the nation mostly dry away from the southwest with a dry airmass and stable atmosphere in place.

Thursday 8th of July 2021

Taking it out 10 days and a large trough moving through the southeast through to the northwest with an upper high off QLD and another over the southwest of the nation bringing settled weather there.

Low pressure off the east coast with areas of rain and thunderstorms moving through QLD then offshore with a drier cold airmass to follow. Showers with wintry mix over the southeast with snowfalls over Alpine areas. High pressure over the southwest of the nation with stable weather for the remainder of the nation.

Lets compare the GFS with Euro to see how the east coast rainfall event is shaping up.


Friday 2nd of July 2021

Similar to GFS has an upper trough moving through the southeast of the nation come Friday with a cold airmass moving through. It will invigorate and upper and surface trough over QLD bringing unsettled weather through the region. Upper high in the same spot over NZ and a new one moving into the southwest of the nation too, so that looks good.

Widespread rainfall through the eastern inland with moderate to heavy falls over QLD and NSW, moving towards the coast. Showers over the southeast with gusty winds and much colder air developing later with snowfalls over Alpine areas. Could be some OK falls over the southeast of SA and southwest VIC if this run is right. The rainfall is more widespread and organised over the southeast and east compared to GFS.

Saturday 3rd of July 2021

Large upper low over the southeast with a strong trough moving through the eastern inland. Large upper high over NZ is one element that all models agree on. The upper low is further north and stronger on the Euro model over the southeast compared to GFS today. High pressure moving over the southwest also verifying.

Rain becoming heavy at times over QLD with the trough responding to the dynamic support of a more northward centred low over the southeast. That will help to bring falls through the southeast inland as well. Snowfalls could be moderate under this solution. A high over the Bight seems fair during this period with showers over southern SA. A new front off WA approaching.

Sunday 4th of July 2021

This is where the models diverge with the Euro suggesting a deeper upper low over the ACT promoting more wintry weather and widespread falls over the southern inland and heavier rainfall over QLD and NSW with the trough moving offshore. GFS has the system off the southeast coast of VIC and weakening. So this is why it is a low confidence forecast. But if I was to side with a model, it would be the Euro, based on its skill scores and it's ability to handle medium term forecasts better.

Widespread rain leaving the east coast with a cold airmass. A wintry weekend with widespread showers, some heavy through Victoria with moderate snowfalls again a possibility under this solution, not as heavy as 24hrs ago. A strong front coming into WA, that is in line with most global models, with moisture dragged in from the Indian Ocean. That look will change out west as we get closer, as the east coast weather will impact the scale and intensity of that feature and when it impacts the southwest. Fine over the central parts of the nation seems fair through this period.


Need more weather information? Tailored forecasts for rainfall, temperature etc can be drawn up for your property. All you have to do is email me at karllijnders@weathermatters.org to find out more. Spots are filling up fast.

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