NATIONAL WEATHER PICTURE - PM EDITION - SUNDAY 27TH OF JUNE 2021

Headlines


  • Widespread showers moving into southwest WA with a first in a series of cold fronts

  • Cold nights returning to the southeast with high pressure moving in with frost developing over the eastern inland.

  • The east dries out for now, but showers increasing from about mid week.

  • Dry season conditions strengthening over the north of the nation.

A cold front is moving closer to the southwest of the nation bringing a burst of showers and storms throughout the southwest of the nation this afternoon. There have already been some showery periods for parts of the west coast, with the activity beginning to move further east and tonight, though rainfall intensity will begin to thin out. Another front moves over the southwest of the state again on Monday night.


Cold nights developing over the southern and eastern portions of the nation with high pressure developing and strengthening over SA, ridging into the east. The high will then develop further over the southeast of the nation becoming slow moving before moving into the Tasman later this week.


The east is drying out in response to that high moving east and kicking the trough and patchy rainfall offshore. But as the high develops and firms over the southeast of NSW, this will swing the winds into the southeast and east over QLD and NSW, bringing in cloud and shower activity from Tuesday but more likely from Wednesday.


There are still hints of more widespread rainfall over in the east of the nation coming up in the 7-10 day range.


Dry season weather is continuing over the Kimberly, NT and parts of Cape York with a drier southeast flow continuing.


National Satellite Imagery - Valid Sunday 27th of June 2021

Cloud off the east coast of QLD is associated with a slow moving trough that has lifted offshore this afternoon with rainfall ending from northwest to southeast over the Capricornia tonight. A cold front has moved through southwest areas of WA with showers and a few storms. The front is falling apart over WA this evening. Areas of low cloud over the inland of NSW and northern VIC, that should break up tonight and areas of mid level cloud over the northwest of WA will continue to move southeast this evening.

The front is the most impressive feature on the satellite picture today, and that has brought some showers and thunderstorms this afternoon with mainly light falls. The showers will persist about the southwest tonight with local hail and thunder overnight. Another front arrives tomorrow. Note, the front is already collapsing as it passes through the inland areas this afternoon.

Temperatures - Valid 5pm EST Sunday 27th of June 2021

Calling it fairly seasonal across most of Australia today, though still chilly over QLD with thick high cloud for most of the morning, now starting to move away. Warm and dry over the north with a southeasterly surge returning, bringing down the heat index. Cool in the southeast but near seasonal with partly cloudy skies. Cold over the south and east tonight. And in the west a colder burst rolling through the southwest of WA with scattered to numerous showers, but mild ahead of the front over inland areas.

A closer look at the southwest and you pick the front as it is rolling through the southwest of the state, mild ahead of that system with increasing clouds this afternoon and this evening, with gusty winds moving through tonight. Fine and mild over the Eucla and through the southern interior. Quite warm over the southern Gascoyne with a northwest to westerly winds and mostly sunny skies.

Radar - Valid 5pm EST Sunday 27th of June 2021

Scattered showers, some heavy through the southwest of WA with local hail and thunder this evening. Quite heavy showers offshore Bunbury could bring gusty winds and small hail over the coming hours. These showers and storms will weaken as they roll over the landmass towards the east.

Trough lifting out off QLD seeing the rainfall ending over Yeppoon in recent hours and cloud decreasing over the Wide Bay and Burnett after a cold and cloudy day with light winds. A bright day on the way tomorrow after a cold night.

Rainfall for the next 10 days - Valid Sunday 27th of June 2021

Rainfall chances are picking up in the modelling for eastern Australia. I am still applying a low confidence forecast for the latter part of this outlook. More rainfall for WA this week and again towards the end of the 10 day period as well. The rainfall looks less likely at this time for northwest WA with frontal weather out of phase with moisture plumes.


GFS Rainfall next 10 days - Valid Sunday 27th of June 2021

Rainfall chances are increasing over the eastern inland of Australia with a trough and onshore wind flow combining to bring showers and storms later in the week. Showers increasing over the southwest of the nation over the coming 2 days with two frontal systems moving through. Otherwise dry over much of the central interior, in line with the climatic drivers supporting rainfall shifting back towards the southeast and east.

CMC Rainfall next 10 days - Valid Sunday 27th of June 2021

Not as aggressive with the inland rainfall over the east and keeps the soaking rainfall on the coastal regions with weak troughs wafting around next week. Note the drawn in rainfall over western QLD with colder air, but this starts to interact with the moisture over the east after this period. So there are similar signals for rainfall returning to eastern inland areas of Australia in early July.

Euro Rainfall next 10 days - Valid Sunday 27th of June 2021

Very different to GFS tonight. Has the high pressure sequence a little more mobile and deepens the system moving through WA and then onto the southeast later this week, helping to invigorate a trough over the eastern inland with a good chance of widespread follow up rainfall for QLD. More details below.


Model discussion and Analysis


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

GFS 00z run - Surface pressure pattern and rainfall distribution underneath the upper flow pattern.


Monday 28th of June 2021

Strong upper high over the southeast with cold nights leading to local frost and dry weather during the day. Long wave over NZ and another over WA keeping the wintry weather limited to the southwest of Australia. Heights about normal through the north of the nation. A weakness over QLD will continue to resolve.

High pressure over the southeast with a strengthening centre over the ACT bringing cold nights and sunny days over much over the central, southern and eastern interior. Dry Monday coming up with sunshine for most areas. A trough offshore QLD slow moving may still bring a few showers to coastal areas. Showers over southwest WA easing during the morning but redeveloping later with another front approaching later.

Tuesday 29th of June 2021

Upper high continues to strengthen offshore Tasmania keeping things settled over much of the nation. A long wave trough over WA with another front moving through the southwest of the nation continues the wintry weather for the southwest. Temperatures on the rise over the NT with a 588 high building further over the region.

Widespread showers and gusty conditions for the southwest of WA, maybe even some areas of light rainfall coming into the west coast of the Gascoyne and southern Pilbara. Thick cloud may develop over the west but with the lifting mechanism sitting further south. High pressure in the east setting up camp and bringing more old nights and sunny days for the southern and eastern areas of the nation. Onshore winds developing from Cape York through to Sydney may bring showers, particularly those areas exposed to the easterly wind profile. Showers may be moderate at times through coastal NSW with very few coming inland.

Wednesday 30th of June 2021

Upper high starting to move away to the east, but a strong surface high offshore the NSW will control much of the nations weather. A long wave passing into the Bight, weakening in response to the strong high in the east forcing the system to lose its dynamic support to provide wet weather. New flat ridge pushing into southwest WA and the upper high over the NT continues to hold firm.

Cloudy through the southeast with strong and gusty northwest winds developing during the day. Showers developing over the southeast of SA later in the day and spreading into western VIC later. Mild and breezy ahead of the front. Cloud developing through inland NSW later with a few showers developing along the Great Dividing Range. Showers, moderate at times along the east coast of QLD and NSW with that moisture being drawn east into the front moving out of the west. Some showers possible over the northeast of the NT but dry weather returns to WA with a ridge building in.

Thursday 1st of July 2021

Upper trough over the central interior moving east slowly, with a strong upper high over NZ continuing to ridge back through the nation to a new upper high off WA. A long wave passing through the Bight will move closer to the southeast states. Upper high over the northern parts of Australia will see a reduction in temperatures but perhaps an increase in humidity.

Upper trough over central Australia will begin to move into the eastern inland, meeting the moisture coming in on the onshore wind profile, that moisture being lifted into scattered showers and a few storms. Mainly light falls for inland areas of western QLD and NSW with this feature as it meanders east. Showers continue for the east coast in onshore winds, but they may decrease north of Mackay and increase about the Mid North Coast. A strong front over the Great Australian Bight is still lurking on the charts and we have seen different looks at this system by models, for now it is a low confidence forecast on that element.

Friday 2nd of July 2021

The upper trough combines with the fast moving cold front moving out of the southern ocean, the two combining to bring a wave of wet and colder weather to the southeast and eastern states. Upper high over the Tasman moving further to the east of NZ with another strong ridge over WA moving eastwards during the day. Heights near normal for the north with temperatures near seasonal, may be a touch humid through the morning ahead of a dry surge.

Widespread rainfall breaking out as the front captures the upper trough and rolls the instability into a deeper moisture profile, thus producing rainfall that will be more widespread over southern and central QLD and through northern and central NSW, marching eastwards. Rain will leave the west of these states early on. Showers decreasing along the coast but patchy rainfall developing from the west. Showers over the southeast of the nation with a front, with cold air to follow bringing the chance of snowfalls to some parts of TAS. New high pressure over the Bight bringing onshore winds and light showers and drizzle to the southern coast line of SA and through WA. Fine elsewhere.

Saturday 3rd of July 2021

Upper trough over the central interior with a broad trough extending to the southeast into a cold front becoming slow moving, creating pockets of unsettled weather. Upper high over the Tasman Sea continuing to remain slow moving. A new ridge over WA moving east, thanks to another long wave passing to the southwest of WA. Heights have come down the NT later this week into the weekend, which may bring a drier airmass into the region from a southeasterly wind shift.

Rain and storms moving through eastern QLD and NSW clearing offshore with a front and trough pushing east. Drier air to follow with colder conditions, especially over the southeast where the front stalls out and creates an unsettled boundary through southeastern inland areas. Scattered showers and a few thunderstorms possible over the southern inland areas of NSW and heavy showers near another trough developing offshore Sydney or the South Coast with onshore winds. Showers increasing over the southwest coastline of WA. Otherwise a big high keeping the rest of the nation dry and seasonal.

Sunday 4th of July 2021

Upper low over the southeast with a trough rolling through interior parts of QLD and another shortwave and upper low over the southern Bight, ridging over the Tasman continues to remain near stationary. Upper high over Tasmania also remaining slow moving and cradling the upper low over the southeast. Ridging approaching the southwest of the nation with clearing conditions.

A series of troughs over the south and east of the nation with pockets of unsettled weather. A trough near the South Coast or Central Coast of Sydney may bring showers and storms with moderate to heavy coastal falls in a slack pressure pattern. Rain and storms clearing offshore the QLD coast with a trough leaving the east. Broad trough over the south of the nation with cold conditions and scattered showers with local hail and thunder about. A stronger shortwave may bring another burst of showers and cold conditions for the south of SA and WA. Fine elsewhere with a high bringing southeasterly winds

Wednesday 7th of July 2021

Taking it out 10 days and broad troughing over the southern parts of the nation with a zonal flow over the nation with a jet stream, largely inactive. A few areas of low pressure in the wavy flow, showers and storms may break out in scattered pockets. This is still a low confidence forecast period, the models persist with more chances of rainfall through parts of southern and eastern Australia.

Rain and or showers over the south and southeast with a series of shortwave troughs passing through with gusty conditions and cold weather returning. Snowfalls may develop over the Alpine areas. Upper trough over QLD may spark some patchy rainfall over the interior of the state. High pressure ridging well to the south of the nation suppressing the westerly wind belt and the long waves at this stage. That is in line with the climatic driver being in a positive phase.

Taking it out the next day and you can see the wavy flow bringing up rainfall chances for southeast and southern Australia with a series of shortwaves. Rain breaking out over QLD with a trough being captured by a front and tapping into moisture that is lingering through the outlook period. This is still a low confidence forecast as we have seen many different looks at this period.


Lets compare with the latest Euro model for later this week into the weekend to see how it stacks up against GFS.


Friday 2nd of July 2021.

Euro showing a upper trough passing through in greater strength, suggesting the upper high over the Tasman will be moving further east. A more zonal pattern which would mean better rainfall chances for the southern parts of the nation. Broad troughing through the interior keeping the dry season going for northern parts of the nation.

Euro is a little quicker with the front and has a more dynamic system, so the rainfall more widespread and heavier through QLD and NSW with a few storms. Showers extending through NSW down into VIC with lighter to moderate falls and gusty conditions. Showers over southwest WA later with the approach of a front. Fine elsewhere with high pressure dominating.

Saturday 3rd of July 2021.

Upper trough slowing down and cutting off into an upper low over Bass Strait with wintry weather over the southeast. A trough extending through the east, with weak ridging over the west of the nation. Note the upper high over the Tasman on the Euro is not as strong or slow moving over this period, where GFS is much more aggressive with the high pressure ridging.

Rain and storms ongoing through QLD clearing the southeast and Wide Bay during the day, but may persist over the Capricornia and extend inland, with moderate falls about. Some clearance expected through much of NSW with high pressure ridging in with a dry southerly flow. Showers, with small hail and thunder over the southeast easing during the day. Fine over in WA with gusty northwest winds developing ahead of a strong front offshore.

Sunday 4th of July 2021.

Upper low slow moving over the southeast with a trough moving through the eastern inland continuing to bring some colder and wet weather about the region. Upper high over NZ slow moving at this point, a weaker ridge over WA continuing to advance east, pushed along by a much strong long wave offshore the west coast. Fine over the north under a developing upper high.

Showers clearing the QLD coast as a trough lifts out and a colder southerly follows. Showers easing over the southeast with a low beginning to move away. High pressure engulfs the nation keeping most areas dry and cool. A strong cold front with potential cloud band offshore the west coast could bring the next decent rainfall event to the west. But if you look at GFS, it is completely different, so I am once again assigning a low confidence forecast for the period of day 6-10 with lack of clarity from all models.

Need more weather information? Email me at karllijnders@weathermatters.org for further details about detailed information for your part of the world.






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