NATIONAL WEATHER PICTURE - PM EDITION - TUESDAY 29TH OF JUNE 2021.

Headlines


  • Showers decreasing over WA with a front weakening over the southeast of the state today.

  • Showers about the east coast with some moderate falls about for some locations.

  • That moisture to feed a trough moving through the eastern inland of the nation. Models continue to struggle with this feature as expected.

  • Cold outbreak for the southeast later this week to add more complications to the forecast packages over the east and south.

It has been showery through parts of WA today, especially this morning but conditions have begun to dry out as a the westerly wind regime begins to stabalise in response to a high ridging in from the west. Overnight some locations reported 30-40mm and only light falls about today.


Showers about the east coast have been scattered through the past 24 hours with moderate falls about the coastal fringe, with the showers expected to increase along the north coast into QLD over the next 24 hours as the winds turn more easterly. Partly cloudy over the eastern third this afternoon.


The moisture producing cloud through inland areas is heading west and will likely meet a weak surface trough over inland QLD and NSW tomorrow, to see showers developing during the afternoon and more likely at night through these areas. The moisture continuing to produce showers over the east coast will feed deeper moisture into this feature later this week.


A cold outbreak expected to sweep the southeast from Friday with a strong cold front pumping through at pace, however the cold outbreak is not being handled well which is having complications in terms of pinning down rainfall totals for the eastern inland event, with chopping and changing expected to continue for the next 24 hours.


National Satellite Imagery - Valid 5pm EST Tuesday 29th of June 2021.

Cold front streaming through the southern part of the Bight now being forced south by a strong high over the southeast. Showers and colder air can be seen in the southwest, but the air is becoming more stable this evening about the west with a ridge moving in. Clear skies for a lot of the south and eastern inland although cloud has developed through a lot of QLD with a weak surface trough over the western inland and cloud with showers about the east coast.

A cold front blasted through the southwest is continuing to push eastwards today with showers decreasing today though some of the showers have been wintry over the south coast with local hail and wind squalls reported. Overnight, 30-40mm reported from showers and 1-10mm today with showers clearing overnight.

Been a pretty good looking day over the southeast with a high pressure system sitting over VIC this afternoon. On the northern flank of the high pressure system, easterly winds are bringing humidity and showers towards the coast and moderate falls have been reported. The cloud extends inland with the moisture expected to stream further inland overnight into Wednesday feeding a trough over QLD and northwest NSW.

Temperatures - Valid 5pm EST Tuesday 29th of June 2021

Mild to warm over large parts of eastern WA and wester SA as well as western QLD and much of the NT, with high pressure promoting warm temperatures. The warm air being dragged southeast via northwest winds towards the Eucla today. In the east, onshore winds keeping the temperatures seasonal and conditions about the southeast also seasonal under high pressure. Colder back in the southwest following the cold front.

Spot the cold front! It is bringing dry colder air through the SWLD, however the front is anticipated to fall away to the southeast with the cold air also sliding southeast and away from the coast line during the next 24 hours, so mild winter weather to continue over SA over the coming days before the front on Friday.

Radar - Valid 5pm EST Tuesday 29th of June 2021

Showers about the west coast easing in frequency and becoming more isolated this evening, with scattered showers south of Geraldton expected to weaken this evening as the front collapses over the east. Can spot the remains of the front east of Esperance bringing gusty winds and a few showers. Showers with hail about the south coast easing overnight.

Showers continue between Brisbane and Sydney today, with light falls for most along the coast. The moderate falls will likely develop tomorrow as easterly winds develop. The showers extending then north to much of the QLD coast north of Brisbane and up to Cape York.

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

Widespread rainfall developing for the east is still a good chance, the models bringing the rainfall west a tad tonight through to the eastern parts of SA, but not changing the rainfall too much for the region yet. Showers easing for the southwest overnight before a string of fine days ahead of more rain this weekend, which could be heavy. The cold outbreak, very tricky to pin down rainfall for this event with model divergence continuing so low confidence in numbers for the region.

GFS 00z run Rainfall next 10 days - Valid Tuesday 29th of June 2021.

Rainfall still moving around and waning a little, in response to the uncertainty with the cold outbreak over the southeast that is causing the trough over inland QLD to shift around a bit, moving quicker to the east one run, and then slower the next. I suspect this will continue for another 24-36hrs and only settle once the trough is active tomorrow night and the front through the southeast is being analysed in real time.

CMC 00z run Rainfall next 10 days - Valid Tuesday 29th of June 2021.

Now starting to increase rainfall....FINALLY, for QLD and NSW, realising the moisture and trough will combine to bring moderate to heavy rainfall for many locations over the southeas tof QLD and parts of northeast NSW. Some of the rain that hangs back through central and western NSW and QLD could be moderate as well but connected thunderstorms that form.

Euro 00z run Rainfall next 10 days - Valid Tuesday 29th of June 2021.

The evening Euro still quite wet and extending the moisture back through most of NSW and creeping into eastern SA with the moisture trying to get in front of the cold blast on Friday. I am not going to draw it in just yet for the region but certainly will increase totals if this trend continues. Rain looks good for NSW and QLD but that southeast system is certainly the low confidence component, which continues to drive the models a little haywire this evening. Still no consensus.

ACCESSG 12z run Rainfall next 10 days - Valid Tuesday 29th of June 2021.

The local model does support significant rainfall for eastern and central QLD but once again probably not handling the southeast cold outbreak well so it is hard to have faith in all the elements out east producing rainfall, but the signals are good for QLD. Moisture over WA much deeper later in the period, other global models struggling with the timing and whether the moisture gets dragged into frontal weather mid next week. So that is low confidence.

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 the southeast continue to control the weather for the east, though helping to sling moisture onto the east coast feeding an inland trough which is weak, but on this chart, likely to be invigorated by an upper trough that edges in from SA. A weakening long wave that brought the cold and gusty weather over southwest areas of the nation continuing to weaken, slamming into the large upper high. A new ridge over southwest WA.

Showers tonight and tomorrow over the east coast with onshore winds continuing. Showers could be moderate at times for coastal areas. Showers developing through inland QLD during the afternoon and evening, mainly west of Thargomindah to Windorah but some thunder may also accompany these storms after dark as they move east. One or two isolated showers over inland VIC and NSW along the ranges. A little rain possible about the SA coast with that weakening front. High pressure over WA, quickly moving in and restoring fine weather.

Thursday 1st of July 2021

Upper high over the Tasman continuing to strengthen as it heads east over the country. An upper trough invigorating the surface trough from Wednesday over inland QLD now extending south into western NSW. A long wave emerging well south of the nation surging northeast with a cold airmass. Upper high weakening over northern Australia with falling temperatures. Fine over the west under flat ridge.

Showers increasing in coverage over inland QLD and NSW with a few thunderstorms as well. Some moderate falls possible with thunderstorms as the trough moves into a deeper moisture layer. Easterly winds producing showers, they could be heavy at times about the north coast of NSW and southeast of QLD and also about the FNQ coast as well between Cairns and Cardwell. Fine weather over much of WA under a flat ridge though the next cold front coming through the Bight may produce a few late showers and strong winds for the southwest and south coasts. Mainly light falls.

Friday 2nd of July 2021

Strong long wave passing through the Bight and onto the southeast with a wintry blast developing later in the day. A broad trough over the inland of Australia extending over QLD and inland NSW producing unsettled weather with a surface trough slowly advancing east. Upper high over NZ continues to be slow moving with very strong heights there. Flat ridge maintains itself over WA with a strong centre of high pressure offshore.

Strong cold front bringing a band of showers/rain through southeast SA and into western VIC with a cold rain to follow the passage of the front. Storms with small hail possible later in the day or at night, the rain reaching Melbourne by afternoon with falling temperatures. Snow over Alpine areas at night. Rain and a few storms continuing through southern and central QLD and northern and eastern NSW with a trough, perhaps some heavy falls near the north coast of NSW and southeast QLD. Fine weather elsewhere.

Saturday 3rd of July 2021

Strong upper trough over the southeast driving wintry weather with snowfalls down to moderately low levels, but light falls expected with a drier airmass ingesting into the region in the southwest airstream. Upper trough and surface trough moving through NSW and QLD quicker than previous runs but again a low confidence forecast remains for this period over the eastern inland. Heights coming down over northern Australia with seasonal weather continuing and perhaps colder nights for the southern NT and western QLD. Ridging kicking off fine settled weather for the west on Saturday though a long wave is offshore.

Rain with a few thunderstorms through eastern QLD and northeast NSW contracting eastwards and clearing with a trough, pushed along by an upper low over the southeast diriving that showery cold weather for southeast SA, VIC and TAS with modest snowfalls continuing down to about 700m. Fine weather returning to much of SA under this belt of high pressure moving in so the showery weather easing over the coastal parts of SA. Fine weather over WA although winds increasing and cloud increasing with a warm airmass descending from the northwest.

Sunday 4th of July 2021

Upper trough over the southeast begins to move southeast (this is stark contrast to other modelling which move the system east and northeast) but with this model jumping around this is a low confidence forecast moving through the weekend. Upper trough moves offshore QLD and NSW. New high pressure comes through SA into the southeast. A long wave trough approaches WA with the next wave of showery windy weather on the cards.

Clearing along the east coast with a dry southerly wind, but don't be shocked if that rain sticks around. Strong high pressure over the southeast will begin to clear out the southeastern inland and coastal areas. A northerly flow over the south of the nation warming the region and keeping skies clear. A strong cold front rolls through WA with a burst of rain and strong winds with falling temperatures. Fine over the north with a tad more humidity than usual.

Monday 5th of July 2021

Strong upper trough over the southwest driving potential severe winter weather with a damaging wind profile and cold air. Ridging over the east with settled conditions after a cold night. Trough offshore the east coast moving further east. Still a large and powerful upper high over NZ remaining stubborn.

Widespread rain and strong winds over the southwest with gusty winds and cold temperatures. Local hail and thunderstorms also possible with moderate to heavy falls about the far southwest. Fine weather everywhere under a strong high pressure with cold nights for the southeast but mild and sunny days with a northerly flow developing through the southeast. Seasonal weather for most other regions with dry skies near everywhere else across the nation, bar perhaps the Cairns region.

Tuesday 6th of July 2021

Strong long wave trough rolling through the Bight, the bowling ball expected to continue advancing east in about a week taking the cold and wintry weather from WA through to SA with a series of strong cold fronts embedded in the trough. Ridging in the east keeping the region mild and sunny after cold starts. Flat ridge over the north with higher humidity values building.

A strong cold front from WA moving into SA though weakening on the approach to central SA. Light rainfall at this stage Strong and gusty northerly winds in advance of the front will keep the region very warm for this time of year. Clearing over the east coast with heights coming up. The rain should be over by this stage, regardless of which model you look at. Another front moving into southwestern parts of the nation with strong southwesterly winds and below average temperatures. More humid over the north.

Friday 9th of July 2021.

Strong long wave continuing to evolve through the southern ocean as the SAM continues to trend negative through this period (catch the latest on the impact here ). The fast flow pattern will continue to drive windy wintry weather over southern Australia under the current guide. An upper high over QLD in its winter position supporting the windy fast moving zonal winter flow over southern Australia.

Widespread showers with strong to gale force winds as a wavy westerly flow continues to control southern Australia. A belt of high pressure being analysed for much of the mainland, keeping the subtropics and tropics dry and mild. Snowfalls developing over Alpine areas through this period and could be quite productive with average to below average temperatures.

Taking it out to mid month and that signal for fast flow pattern to persist with fronts becoming active throughout the 2nd and 3rd week of July. We will see how that signal verifies but the climatic drivers are supporting a shift to this type of weather.


Before I sign off - lets have a look at the Euro for the trough over the east and the cold outbreak over the southeast to see how it fairs in comparison to GFS.


Friday 1st of July 2021

Upper trough in a similar position to GFS bringing a burst of gusty winds and rainfall through SE SA and into western VIC later in the day with falling temperatures. Upper trough and surface trough triggering widespread rain and a few storms through central and eastern QLD, though tonights run is a little quicker. Upper high over NZ.

Widespread showers developing over the southeast with a cold outbreak moving through. Rain and storms widespread through the east, but moving out to the east a little quicker than this morning's run so again still some uncertainty in the modelling on the cold outbreak speed, the trough's speed in response over the east. This will play with the rainfall numbers over the regions. Fine weather moving into southwest parts of the nation is in good agreement.

Saturday 2nd of July 2021

Upper trough passing through southeast Australia, not as strong and as far north as this morning meaning that the cold outbreak with deep instability has a lesser impact over the southeast of the nation and also will not pull the trough south or southeast, slowing it down, meaning the systems will now clear quicker on current guide, but the rainfall totals as the rain band passes over the east still could be productive.

Rain and storms continuing for much of QLD and northeast NSW but will likely lift out through the afternoon and clear about 12 hours earlier than this morning's guidance. Showers and a cold southwesterly flow but the low is much further south of Tasmania, where this morning it had the low over Melbourne and into Bass Strait. This will see less rainfall and less snowfalls over the coming weekend.

Sunday 3rd of July 2021

Weakening upper trough over the southeast moving over the east of Tasmania with a surface low well south of where it was this morning. The low was anchored over Canberra this morning, so stark difference in rainfall and snowfall potential for the southeast. Clearance over the east coast. But one thing this system moving further east will do, is introduce a stronger weather system for WA which may produce severe weather on Sunday.

Rain and storms leaving the QLD coast during the morning, with a drier cooler flow to follow. Showers, more frequent over southern VIC with a southwest flow, easing later. Clearing through SA. Windy with late rainfall for WA with quite a significant burst of moisture moving southeast into this front, so will be keeping an eye on trends to see if rainfall certainly increases for this event later on Sunday.


Need more weather information? Email me at karllijnders@weathermatters.org for further details about tailored forecasts. It could assist in your decision making so don't hesitate to reach out, spots are filling up fast.

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