August 2002 Forecast Outlook, Discussion & Report Page

Victoria
Date Name

Information
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September 2002 Forecast Outlook, Discussion & Report page
31 . Overview: The trough associated with the low near Tasmania which extended through New South Wales and southern Queensland during Friday has moved east to be close to the coast, and has left a remnant trough west of the Great Divide in Queensland on Friday night.  A trough over South Australia is affecting the northeast of that state as well as western New South Wales triggering showers and isolated storms.

A series of fronts is crossing the Bight, with Tasmania's weekend weather to be affected by their passage. The high in the Indian Ocean continues to ridge towards the west coast at between 20 and 30°S, while the centre further to the west remains nearer to 40°S.

Discussion: The trough will drift east through eastern Australia during Saturday and edge south of the ridge along the Queensland coast from the high in the Tasman Sea. The high in the Indian Ocean continues to strengthen slowly, and its 'positive longitudinal' (NE - SW) alignment is helping to steer a series of troughs and fronts northeast towards the Australian mainland. A deep low (963hPa at 10am AEST) will move ENE through the southern Bight during the weekend. Fronts will continue to affect the southwest of the continent during the weekend triggering showers which become more frequent with the passage of fronts with the chance of a storm, mainly over the Bight.

This phase change away from dominant high pressure over the continent will allow a series of fronts and troughs to affect lower latitudes over Australia, particularly in the east.

Rainfall potential
Victoria: A trough moving through the state Friday night and Saturday will trigger showers in the west and north.  Snow showers developing over alpine areas above 1500m.  Isolated storms, mainly in the west, but falls will be light in most areas.
NSW:  Scattered showers in the south and west during Friday night, spreading east through Saturday and becoming more frequent.  Isolated storms on the southwest slopes, central tablelands (reaching the coast later Saturday).  Isolated snow showers above 1500m.
Queensland:  Scattered showers and isolated storms are likely west of the ranges in the south of the state with the trough lingering inland.  Isolated showers over the northeast tropical coast.
NT:  Mainly fine with only isolated showers in the north along the coast.
WA:  Fine in the north.  Scattered showers becoming more widespread with the passage of a series of fronts and troughs through the weekend. Chance of a storm, but mainly over the sea.
SA:  Showers with isolated storms in the east and northeast through Friday night and into Saturday morning, contracting east and clearing.
Tasmania:  Scattered showers developing in the west and northwest during Saturday and spreading east with frontal passages through the weekend.  Generally unsettled except for the east of the state where conditions will remain mainly fine until later in the day.
30 . Overview: The high in the Tasman Sea remains slow moving and is helping to slow the eastward movement of the systems currently over Australia. A trough extends through the eastern states from the low drifting eastward south of Victoria through Bass Strait triggering showers and storms through central and northern New South Wales and southern Queensland.  Storms in Bass Strait and south of Tasmania are also associated with the low.  A remnant of the ridge through central Australia remain over northern South Australia between two troughs. A wave low south of Western Australia extends a front through the southwest of the continent and is triggering showers, with isolated storms over the western Bight.

Discussion: The trough over eastern Australia will continue moving to the northeast during Thursday night and Friday triggering scattered showers and storms, likely to become more frequent within the trough through Friday. The low will edge in an easterly direction and reach the Tasman Sea later   Friday. Showers may become more frequent to the northwest of this low over southeastern South Australia and Victoria in the southwesterly flow between it and ahead of the next trough.

The high over the Indian Ocean will ridge into the west of the continent near to 25°S later Friday / Saturday but will steadily cover higher latitudes to the west - when the main centre reaches the west coast it is likely to be close to or south of 40°S - this setup is likely to facilitate the northeast movement of a series of lows and troughs (and cold air) associated with a broad trough towards the continent.

Rainfall potential
Victoria: Showers, mainly in the southwest. Showers and scattered storms in the east clearing through Friday. Highland fog and drizzle over alpine regions.
NSW:  Showers and storms moving through the northeast of the state during Thursday night and Friday morning. The trough and associated activity may lag in the northeast during Friday. Showers are possible in the southwest of the state and over alpine areas.
Queensland:  Isolated showers over the northeast tropical coast.   Scattered showers and storms associated with the northeast movement of the trough, mainly in the south and east.
NT:  Patchy cloud in the northeast but remaining dry, fine and clear elsewhere.
WA:  Fine through most of the state with showers and isolated storms (the latter mainly off the coast) in the southwest, becoming more frequent with the passage of fronts.
SA:  Showers likely to redevelop over the southeast. A trough moving through the state may trigger isolated showers.
Tasmania:  Showers over the state, clearing during Friday.  Scattered storms likely mainly Thursday night.
29 . Overview: A midlevel pool (850 - 750hPa) of moisture with strong lapse rates through these levels is located over northern New South Wales / southern Queensland today, while the entire east of the continent has seen a general cooling during today along with a buildup of moisture. The low in the Bight has weakened and edged south with the cloudband tilting over Victoria this afternoon with moderate falls reported in the west and southwest of the state. A weak trough extends north into western New South Wales.

The heat trough over the Pilbara and Kimberley is becoming more frequently apparent. The high over southern Western Australia has almost been absorbed into the lower pressures surrounding it, while a weak front is approaching the southwest. Upper moisture (and cloud) moving across the Western Australia coast and through into South Australia (and can be traced in to New South Wales) marks the location of the upper jet.

Discussion:  During Thursday, the remnant high will move steadily east across the continent between two troughs.   The low in the eastern Bight will move slowly southeast and fill in, and the cloudband associated with this will continue to trigger showers as it moves across the southeast. The high in the Tasman Sea will begin to loosen its hold over the synoptic situation in our longitudes, but will maintain its ridge along the Queensland coast through Thursday.  The trough moving through western Queensland and northern New South Wales will have its eastward movement slowed by this ridge, and a buildup of moisture closer to the coast is likely to trigger scattered showers and isolated storms through Thursday.

The front and trough moving through the southwest of the continent  will weaken, with showers in the southwest becoming less frequent as the system moves east. West(southwest)ward moving convergence lines of cirrus will move through the Arafura Sea during Wednesday / Thursday. Some moisture will continue feeding into the west of the continent from the Indian Ocean.

Areas to watch: The high ridging towards the west coast is located close to 40°S - the alignment of this high is likely to facilitate the northeast movement of a series of lows and troughs (and cold air) associated with a broad trough towards the continent closer to the weekend.

Rainfall potential
Victoria: A rain band associated with the front moving across much of the state during Wednesday night and Thursday morning.  Conditions clearing from the west with isolated showers in the south. The risk of an isolated storm mainly in the south.
NSW:  Scattered showers and the risk of isolated storms in the north of the state as well as central areas.  Patchy rain in the southwest, extending east to the coast, then clearing from the west.
Queensland:  Scattered showers and isolated storms possible in the south and east of the state, isolated showers along the northeast tropical coast.
NT:  Isolated showers over the far northeast.
WA:  Fine in the north.  High cloud in central parts with the jet.  Scattered showers in the southwest spreading east and becoming less frequent.
SA:  High cloud crossing the state.  Mainly fine with isolated showers in the southeast clearing early Thursday. Isolated showers redeveloping along the southwest coast as the high moves east.
Tasmania:  Showers in the northwest tending to rain and spreading southeast through the remainder of the state.
28 Clyve Herbert There seems to have been an (welcome) intensification of the rainband moving through central and north central Victoria this evening with some falls approaching 20mm west of Ballarat. Intensification appears to have occurred within an amplifying mid level trough as it moves into a warmer moister mid level flow over the central areas of Vic.
28 . Overview: The high in the southern Tasman ridges along the Queensland coast and has helped block the movement of the systems to its west. A strong upper ridge extends from the southeast of the continent to the Kimberley. The low in the head of the Bight on Tuesday night deepened slightly through the day  to 998hPa but has remained quasi-stationary.  A  weak trough and front extend through South Australia with only scattered showers and isolated storms at this stage. The ridge of high pressure through the southwest of the continent then ridges southeast through the Bight and looks to cut the low off.

Discussion:  The high in the Tasman will remain slow moving through Wednesday and maintain a ridge along the Queensland coast as well as another ridge to the northwest. The low in the Bight will move in an east-southeasterly direction during Tuesday night and through Wednesday and may weaken as it continues to move into dry air at the surface. There is however midlevel colder air currently over the Bight, which may trigger further instability if it becomes drawn into the system. An upper low associated with the thermal trough in the western Bight will continue to move northeast towards the southern coast and may translate to the surface.

The ridge of high pressure in the west will build through southern Western Australia during Wednesday and ridge to the southeast through the Bight. The midlevel cloudband approaching the coast near Geraldton is weakening and is not likley to produce anything other than an isolated shower through the Gascoyne or Goldfields regions.

Areas to watch: The high in the Indian Ocean may approach the continent at higher latitudes than has been the pattern for the past few weeks and help drive significant cold air up through the western Bight later in the week.

Rainfall potential
Victoria: Strengthening northeast to northwesterly winds from the west with increasing cloud. Showers tending to light patchy rain will develop in the west.  The risk of an isolated storm. Conditions will remain mild.
NSW:  Isolated showers over the north coast in the southeasterly flow before turning northeast to northerly as the high begins to move away. Increasing cloud and patchy light rain in the southwest. Fine elsewhere.
Queensland:  Isolated showers along the east coast.  Mainly fine elsewhere under the influence of the ridge.
NT:  Fine throughout.
WA:  Showers along the southern coast tonight then clearing.  Mid level cloud crossing the west coast near Geraldton but only very isolated showers are likely.
SA:  Showers with the passage of the trough and front Tuesday night and Wednesday. Winds shifting cooler southwest from gusty northwesterly preceding the front. Scattered showers in the south.
Tasmania:  Cloud increasing in the west with patchy rain developing. Dry elsewhere over the state.
27 . Overview: The high in the southern Tasman Sea extends ridges to the northwest and northeast, cradling the low in the Coral Sea and edging it towards the North Island of New Zealand. Fine conditions becoming milder have been widespread through southeast Australia after a cold night. Showers with isolated storms, mainly off the coast, along the east coast, mainly between the New South Wales mid north coast and Fraser Island have been courtesy of a moist southeast flow between the Coral Sea low and the high in the Tasman. 

A satellite low is moving around the low in the southwestern Bight (976hPa at 10amEST) behind a trough moving through the southeast of Western Australia during Monday night and bringing showers to the southwest.

Discussion:  The high over the southern Tasman (which has solid upper support) is likely to remain slow moving through Tuesday, helping tighten the pressure gradient over southeastern Australia later Tuesday and into Wednesday with strengthening north to northwesterly winds as a result.

Cyclogenesis within the deepening trough in the Bight, with increased warm advection ahead of a trough moving along the southern coastline and strengthening northwesterly winds will bring warmer conditions to South Australia and Victoria during Tuesday.  A colder southwesterly airstream with showers and isolated storms will follow later Tuesday in southeastern South Australia and likely Wednesday through central Victoria and Tasmania.

Areas to watch: The moisture plume feeding towards Western Australia from south of Indonesia may bring with it some reasonable falls if it maintains its integrity over the next day or so.

Rainfall potential
Victoria: Strengthening northerly winds in the west with a mild and mainly fine day after a cold night with widespread frosts. Cloud & highland fog developing mainly on the windward slopes of the alpine areas.
NSW:  Scattered showers over the north coast, becoming less frequent through Tuesday. Mainly fine with warmer conditions elsewhere with areas of low cloud developing mainly on the windward slopes of the alpine areas.
Queensland:  Isolated showers in the southeast in a moist onshore flow.
NT:  Fine throughout.
WA:  Fine in the north.  Showers in the southwest extending east along the coast with isolated storms mainly over the Bight, but possible over the coast. Showers will clear from the west through Tuesday.
SA:  Strengthening north to northwesterly winds ahead of a front with warm conditions becoming milder with a west to southwesterly wind change behind the front later Tuesday through south central and southeast of the state. Only isolated showers with the front close to the coast are likely.
Tasmania:  Strengthening north to northwesterly winds.  Mainly fine.
26 Clyve Herbert Not a bad looking system south of Japan! however I have been watching a convective area southwest of Indonesia that looks rather interesting -  not bad for August!
26 . Overview: A small surface to 850hPa low has formed over the Coral Sea this afternoon near 20°S just to the east of the trough over eastern Queensland. The upper jet is also feeding moisture into this area from south of Indonesia. Within the trough over Queensland, which has been edging south into New South Wales through Sunday is an area of vorticity which should be watched. A strong dumbbell high is crossing Bass Strait / Tasmania and moving into the Tasman Sea near to 40°S. The trough and frontal system crossing southern Western Australia is drawing some moisture from the subtropical Indian Ocean.

Interesting: Storms in inland Queensland during Sunday, sleet on the Central Tablelands of New South Wales late Sunday.

Discussion:  The cloudband associated with the trough through Queensland will continue to edge southwards through New South Wales during Monday.  The low in the Coral Sea will deepen and move southeast, bringing a continuation of showers along the Queensland coast.  The high over southeastern Australia is likely to maintain both its strength (near to 1031hPa) and also maintain the ridge to the northeast under the Coral Sea low hindering its movement along the coast and helping steer it away to the southeast. A satellite low is likely to form on the western side of the low moving southeast through the western Bight and move around the upper trough initially towards the southern Western Australian coast before turning southeast towards the west coast of Tasmania

Areas to watch: The moisture plume feeding towards Western Australia from south of Indonesia may bring with it some reasonable falls if it maintains its integrity over the next day or so.

Rainfall potential
Victoria: A cold night across the state.  Freshening north to northwesterly winds in the west ahead of a trough and frontal system.
NSW:  Showers, with possible periods of rain in the north of the state.   Isolated sleet on the higher parts of the Central Tablelands Sunday night. Another cold night inland under clear skies in the south of the state.
Queensland:  Showers, tending to rain periods continuing along the coast during Sunday night and Monday, becoming less frequent.  Scattered showers and isolated storms lingering over the southeast corner. Isolated showers over Cape York.
NT: Fine.
WA:  Fine in the north. Showers continuing in the south, mainly over the southwest corner, more frequent with the passage of a further front during Monday.
SA:  Warm in the west with increasing cloud and strengthening northwesterly winds ahead of a trough and front. Only isolated showers likley through the southern parts of the state.
Tasmania:  A cold night with frost over the hihger parts. Isoalted showers in the west and north later Monday.
25 . Overview: The high in the eastern Bight extends a ridge along the east coast, effectively halting the eastward movement of the deepening trough over Queensland. Showers and storms west of the   Queensland ranges have been active during Saturday afternoon and evening, especially along what appears to be a dryline setup. A trough and weakening cold front associated with a 988hPa low just southwest of Western Australia is crossing the west coast and moving through the south of the state during Saturday night / Sunday morning.

Discussion:  The high will remain slow moving near to 40°S across Bass Strait / Tasmania during Sunday.  The ridge along the east coast will weaken somewhat, allowing the trough over Queensland to move towards the coast. Widespread areas of showers and scattered storms are likely within this trough and will dominate weather over much of central and southern Queensland during Sunday.

A ridge to the northwest through South Australia and the Northern Territory will strengthen. The low near the the southwest of Western Australia will slide southeast though the western Bight region, with likely increased warm advection at 850hPa ahead of the front as it moves east. Strengthening north to northwesterly winds ahead of this system will increase temperatures through Sunday in western parts of South Australia.

Rainfall potential
Victoria: A very cold night in most districts under clear skies with light winds.   Widespread frosts, some severe with some minima, particularly in the alpine areas reaching very low levels. A mainly fine day except for patches of drizzle on the east coast.
NSW:  Showers and scattered storms likely over the northeast mainly during Sunday. Another very cold night in the south with widespread frosts.  Light south to southeasterly flow over much of the state.
Queensland:  Widespread showers with scattered storms over central and southern parts, most frequent in the southeast.  Periods of rain likely along the central coast.
NT: Isolated showers over the northeast.  Fine elsewhere.
WA:  Fine in the north.  Showers in the west and southwest with the passage of the front, possible storms, mainly in the southwest.  Isolated showers in the southeast.
SA:  Warming in the west.  Mainly fine elsewhere through the state.
Tasmania:  Showers in the west and south increasing into Sunday.  Cold with frost overnight in the east.
24 Clyve Herbert Yet another upper trough starting to generate a large area of mid and high cloud over central south QLD, this development looks to have the upper vorticity over northwest NSW and is rather weak.
24 . Overview: Friday evening's overview has a trough (at all levels) over the Tasman Sea extending as far south as the Southern Ocean with associated cyclogenesis, a well defined deformation zone on the western edge of the extensive mid level cloudband over New Zealand, a cold pool in the middle levels moving northeast over coastal New South Wales, uplift over South Australia on the cold side of the upper jet, a baroclinic cloud patch over southern Northern Territory, a strong high in the Bight and a trough over Western Australia...... and an approaching longwave trough with a 1000hPa low  and extensive frontal system in the Indian Ocean!!

Discussion:  The high in the Bight will remain slow moving and near to 40°S as it edges across the southern Victoria / Bass Strait region during Friday night and Saturday. Very cold nights in southern New South Wales, Victoria and the higher parts of Tasmania under the influence of this high tonight and Saturday night.  A ridge building along the east coast from this high may slow the eastward movement of a weak upper trough. The low and frontal system approaching Western Australia will move just to the south of the state during Saturday

Areas to watch: The baroclinic cloud patch over South Australia on Friday should be monitored during the weekend.   It is likely to move northeast around an weak trough passing over eastern Australia. Shower activity with isolated storms is possible over southeastern Queensland with this upper disturbance.

Rainfall potential
Victoria: Scattered showers in the south and on the southern side of the ranges, with snowflurries likely also in the same areas in a southwesterly to southeasterly flow. A very cold night with severe frosts likely inland and along the ranges. Fine north of the ranges.
NSW:  Very cold nights in the south with widespread, and possibly severe frosts. Isolated showers on and near to the coast, mainly in the northern half.  Fine elsewhere.
Queensland:  Isolated showers over the Cape York area, as well as the southeast with possible isolated storms in the south with the passage of the trough.
NT: Cloudy patches over coastal Top End with isolated showers in the northeast.  Patches of cloud in the south but remaining dry.
WA: Mainly fine in the north. The approach of the low and frontal system during Saturday will see showers and isolated storms likely in the west (mainly south of Geraldton) and south of the state both within the trough over the goldfields area and then later in the day with the front (which looks to weaken as it moves across the state).
SA:  Cold Friday night with scattered frosts and fogs.  Mainly fine through Saturday.
Tasmania:  Snowfalls Friday night in the west and south.  Isolated showers elsewhere.  becoming fine through Saturday.
23 Clyve Herbert (pm) Some interesting stuff over the Tasman Sea this afternoon with what appears to be some potential for heavy rain on the west coast of the south island of NZ,this system is still developing with the cold pool just starting to interact with it over the central Tasman, another mid level cold pool can be seen just near to the north coast of NSW.

(am) Just checking the airmass starting to infiltrate the southeast of Australia which is showing up over Victoria with the signature of 'dry' and cold away from the coast, Looks to be the possibility of near record low minima over the inland of Vic over the next several days, with the possibility of very low minima extending to southern Victoria on the weekend depending on the axis of the ridge, get ready to break the ice in the dogs water bowl.

23 . Overview: The baric ridge meanders across Australian longitudes between 30° and 40° S. Troughs lying over the eastern and western sides of the continent interrupt the continuity of the ridge. An area of upper vorticity is still located over the east coast and is moving southeast. Significant rainfall totals have been recorded in southeastern Queensland and northeastern New South Wales. Pressure over the Northern Territory has declined during the past day.   A midlevel cold pool in the eastern Bight has moved northeast through Thursday to affect Tasmania with snowfalls over higher parts later Thursday, while the thermal trough lags somewhat to the west. A surface front is crossing Tasmania, Victoria and southern New South Wales during Thursday afternoon and evening.

Discussion:  The trough over eastern Australia will continue to deepen and a surface low looks likely to form within the trough off the New South Wales coast and move southeast during Friday.  The high will strengthen in the Bight and help to direct a deep southeast - southwesterly flow across southeastern Australia mainly on Friday and early Saturday, which will decline towards Sunday, with the possibility of very low overnight temperatures as this high moves across the southeast later in the weekend.

The low level trough over Western Australia will deepen through Friday and slowly edge eastward but shows little sign of becoming particularly active except in the far south. 

Areas to watch: A deep longwave trough is approaching Western Australia,  while an area of  tropical infeed from the northwest near to Indonesia is likely to be 'picked up' and drawn into this system as it moves into our region.

Rainfall potential
Victoria: A cold unstable southwesterly will become established across Victoria bringing stream showers to southern and mountain areas. Isolated storms (with hail) in the south are possible.  Snowfalls developing over the ranges, with the snow level lowering during Friday. There is a possibility of a light dusting to lower levels.
NSW:  Showers near the coast and over the adjacent ranges, with some possibly heavy falls, becoming less frequent through later Friday. Scattered storms within the trough, mainly Thursday night. Snowfalls developing over the alps behind the passage of a front Thursday night / Friday morning.
Queensland:  Isolated showers over the northeast tropical coast. Showers clearing from along the southern parts of the coast.  Mainly fine west of the ranges.
NT: Some high cloud over the Top End, mainly fine except for isolated showers in the northeast.
WA: Scattered showers along the south coast.  Fine elsewhere. Some instability within the trough my trigger showers or possible storms in the south.
SA:  Cool in the south with isolated showers along the coast, mainly in the southeast - there is a risk o f isolated storms in the unstable southwesterly flow early Friday. Mainly clear inland.
Tasmania:  Cold over the state during the next 24 - 48 hours with widespread showers, hail and snowfalls, with the snow level lowering overnight and into Friday. Showers becoming less frequent later Friday.
22 Clyve Herbert Have you noticed the wriggly looking cold pool heading north-eastward to the southwest of Tasmania, some impressive cold air CBs in this lot, worth keeping an eye on this area over the next 12 hours,appears the 500hpa temp is very low near to the core of this cold advection,a wish forecast perhaps, but if this cold pool mixes with the east coast vorticity!
22 . Overview: The baric ridge remains south of 30°S with a succession of weak fronts embedded in the westerly flow through the Bight. A weak surface trough is still positioned over Queensland, with upper support in the mid-levels, and this setup continues to feed moisture into the area.   Widespread showers and rain periods along the Queensland coast and hinterland have resulted in 15 - 50mm falls during the past 12 hours. High cloud over South Australia is being drawn into the area of vorticity that is continuing to develop over eastern Australia - this system is currently showing signs of becoming the major influence on the weather over the eastern states during the next day or three.

Discussion:  The high in the Tasman will remain only slow moving, restricting the eastward movement of the trough over eastern Australia. The area of vorticity within the trough looks likely to continue to develop near to the northeast coast of New South Wales. The western extension of the baric ridge is likely to edge south towards 40°S in the Bight during Thursday as the surface trough over Western Australia deepens. There is added support from an upper high which looks to enhance the strength of the surface feature in the Bight, which will likely direct a deep cold southwesterly flow originating from the  Southern Ocean over the southeast of the continent later Thursday and for a day or two following.

Areas to watch: A high of 1042hPa!!!! currently over the Indian Ocean should weaken as it moves east.   Interestingly it is near to 43°S - ~10° further south than currently 'usual' for that area.   A very deep longwave trough west of our longitudes precedes it. Worth keeping an eye on... in between watching the current developments over our part of the country.

Rainfall potential
Victoria: Scattered showers mainly in the south, with the passage of a front during Wednesday night. More widespread showers developing in the colder air following this front, with snowfalls likely to develop at higher levels later Thursday before lowering on Friday. The chance of a storm in the south. Frosts overnight in the north and remaining mainly fine.
NSW: Extensive cloud over the northeastern and central parts of the state is likely to bring widespread showers and periods of rain mainly to the northern half during Thursday, but possibly extending to the south coast later in the day.  Some heavy falls are likely, and there is a chance of storms near the coast. A front passing through the south of the state later Thursday / Friday will bring snowfalls to the southern Alps.
Queensland:  Continuing widespread showers over much of the central and southeast coasts, edging south through Thursday, with locally heavy falls in the far south. Fine in the far west of the state.  Light and scattered showers over the northeastern tropical coast.
NT: Isolated showers over the northeast. Fine elsewhere.
WA: Mainly fine, except in the far southwest,  with a high ridging along the south coast.  A deepening surface trough inland from the west coast is likely to deepen and scattered showers are likely to develop.
SA:  Mainly fine inland for much of the day. Scattered showers in the south and southeast, becoming more widespread later with the passage of a front.
Tasmania:  Widespread showers, occasionally heavy, developing with a series of fronts to cross the state Wednesday night and Thursday. Northwesterly winds becoming southwesterly and colder with snowfalls developing to lower levels later.
21 Clyve Herbert Have you noticed the wriggly looking cold pool heading north-eastward to the southwest of Tasmania, some impressive cold air CBs in this lot, worth keeping an eye on this area over the next 12 hours, appears the 500hpa temp is very low near to the core of this cold advection, a wish forecast perhaps, but if this cold pool mixes with the east coast vorticity! we will see...
21 Nick Sykes The models continue to look very interesting for SE Australia over the coming few days. The latest GASP run is very nice with 524 thicknesses approaching SW Vic on Friday morning and Sub 528 thicknesses over Vic on Sat morning. 850 temps below -4 are progged. These are some impressive values, and AVN is backing them up to a degree, NGP is less in agreement. Haven't looked at EC yet. Moisture will be the key, and it could end up been quite dry over the Melbourne area with the rain shadow effect of Tassie, but as some have mentaioned, with a progged SE flow developing some heavy rain could develop over Gippsland and SE NSW. Combined with the cold air, there could be some very heavy snowfalls.

Good to see a cold pool in the Southern OCean, and it is nice to see the Queensland trough moving SE.
21 Clyve Herbert Interesting stuff over central QLD with what seems to be a precursor low near to a vorticity max just southeast of Winton and moving southeast, also a rapid development in the mid and upper cloud band over northern NSW, there is some potential for southeast QLD in this development and even some respectable falls over coastal northern NSW later.
21 . Overview: The baric ridge (stronger to the west of our area) maintains its position across the continent near to 35°S with supporting upper highs just to its north. The trough through inland eastern Australia has weakened through the day and the cloud associated with it has begun to break up. A satellite low to the southwest of Tasmania is associated with the lows in the Southern Ocean and has a front approaching Tasmania on Tuesday night, with the northern trough extension to affect southern Victoria. A weak (inactive) trough is located over Western Australia parallel to the west coast.

Discussion:  The baric ridge will remain in approximately the same position as during Tuesday, and may strengthen slightly. The trough through Queensland looks likely to continue to weaken out but will help with widespread showers along the Queensland coast, with some heavy falls likely. A series of fronts will affect mainly Tasmania and southern Victoria during Wednesday in the westerly flow to the south of the baric ridge.

Areas to watch: there are signs of vorticity in the area of cloud currently over southern Queensland which is worth keeping an eye on for further developments over the next day or two .....

Rainfall potential
Victoria: Isolated showers in the southwest with fronts passing to the south of the state.  Light showers / drizzle also likely over the ranges. Mainly dry over the rest of the state with frosts in areas under clear skies (mainly in the northwest).
NSW: Cloud increasing over the northeast with scattered showers, mainly coastal.  A weak remnant front will cross the south of the state overnight Tuesday but with little effect. A cold night inland.
Queensland:  Showers along the entire east coast, adjacent ranges and possibly into central regions, extending to the New South Wales border, with some heavy falls.  Cloudy with mainly dry conditions in the west.
NT: Patchy cloud over the northeast of the Top End with isolated showers.
WA: Isolated showers over the southwest extending along the southern coast through Wednesday and becoming only occasional.  A weak upper trough over the west will remain largely inactive.
SA:  Weak fronts are likely to clip the southeast coast during Tuesday night and Wednesday, triggering scattered coastal showers, while inland areas remain mainly dry.
Tasmania: Scattered showers in the west with passing weak fronts over the next 24 hours. Cold in the eastern and central areas with fogs likely Tuesday night.
20 David Jones It is worth having a look at the latest runs of GASP, UK, NOGAPS, and ECMWF for Thursday through Friday. Depending on the exact scenario, these suggest a significant (though anticyclonic) cold outbreak is possible late this week over southeast Australia. With thickness values in the range of ~526 through 532 over Victoria/southern NSW/Tasmania, snow levels "should" fall to 500m or lower. One thing to watch is a UK model type scenario which puts the cold pool over central NSW with a ESE/SE flow. Such scenarios can occasionally produce impressive snowfalls on the southern and central highlands. Of course, the usual disclaimers apply to the models!
20 . Overview: The high in the northeastern Bight continues to dominate the weather in the south and west of the country. A broad ridge extending along the Queensland coast from this high has halted the eastward movement of a deepening surface trough through inland Queensland, extending southward  toward central New South Wales across the northeast of the state. The upper trough remains across New South Wales. A series of cold fronts is embedded in the westerly belt to the south of the baric ridge.  A large and moderate strength centre of high pressure (1032hPa) is edging very slowly towards the west of the continent.

Discussion:  The high will become established over New South Wales during Tuesday allowing the surface trough over Queensland to move eastwards, towards the coast. Scattered showers, tending to rain periods, mainly in the southern parts of this trough are likely through much of inland Queensland, especially near to the ranges, and also through northeastern New South Wales. Scattered storms are likely during Tuesday, most frequently near to and along the trough axis. The cold fronts embedded in the westerly belt will affect Tasmania in particular, while possibly clipping the southeast coast of South Australia and coastal parts of Victoria, triggering showers and drizzle.  Satellite lows in the southern Bight are not likely to have much effect on continental Australia, but will trigger further showers over Tasmania.

Rainfall potential
Victoria: Isolated showers mainly in the southwest and along the northeast ranges. Mainly fine, although partly cloudy south of the ranges.  Fine and clear in the north with widespread frosts, some locally severe.
NSW: Mainly fine in the southwest.  Extensive cloud through much of the state with scattered showers tending to periods of light rain in the north.   Scattered storms, mainly along the ranges in the north and off the coast north of the Hunter.  A cold night in areas under clear skies.
Queensland:  Cloudy with showers over much of the eastern half of the state, with patchy rain with some heavy falls, mainly in the south.  Scattered storms are likely near to the trough axis which should move east towards the coast.  Isolated showers continuing along the central and northern coasts in the onshore flow.
NT: Patchy cloud over the Top End with isolated showers over the northeast corner.  Mainly fine elsewhere.
WA: Fine over most of the state, with isolated showers or drizzle along the southern coast, becoming more frequent with the passage of fronts.
SA:  Isolated drizzle patches over the southeastern corner.  Fine elsewhere after a cold night in most areas with frost patches inland.
Tasmania: Scattered showers, mainly in the west and south.   Mainly fine in the east after a cold night with frost patches.
19 . Overview: The baric ridge has taken up residence across our longitudes at near 35S with the westerlies lying to the south and above the lows which have lost some intensity in the Southern Ocean during Sunday.  The trough over Queensland and through eastern New South Wales triggered isolated storms along the coast as far south as Sydney as well as through inland Queensland near to the trough axis.  The moisture over Queensland has continued to build through Sunday.

Discussion:  The baric ridge will remain near to 35S during Monday, directing the westerly flow to the south of the highs across southern Australia.  The moisture buildup over eastern Australia will continue through Monday, with further storms likely especially near to the trough axis through the inland to the west of the Queensland Great Divide. A weak midlevel trough looks likely to build just off the coast of Western Australia.  A moist onshore westerly through the Bight will bring drizzle patches to the exposed coasts of South Australia, Victoria and Tasmania.

Areas to watch: Widespread convective activity within the trough, mainly over northern and northeastern New South Wales and central and southeast Queensland, is a possibility during Monday.

Rainfall potential
Victoria: Isolated showers along the coast, mainly the southwest of the state and the southwest facing coasts of Gippsland.  A cold night in the north under clear skies with frosts, some severe.
NSW: Showers likely to continue along the coast, particularly in the north.   Isolated storms likely in the northeast, extending southwards, possibly to the central coast through the day.
Queensland:  Isolated showers along the northeastern coast.  Showers and isolated storms inland of the ranges, becoming more prevalent in the south and southeast through Monday.  Cloudy over much of the state.
NT: Mainly fine, except for isolated showers over the northeast coast.
WA: Cold night in the south.  Isolated showers developing along the south coast later in the day.   Mainly fine elsewhere.
SA:  Isolated showers along the coast mainly in the southeast.  Fine elsewhere.
Tasmania: Showers, mainly in the west, continuing through Monday.   Isolated showers in the north.  A cold night in the central and eastern parts.
18 . Overview: There has been a significant buildup of moisture across much of eastern Australia in the past 24 hours associated with the complex troughing at the surface and through the midlevels over the Northern Territory, Queensland and New South Wales. The strong high in the western Bight near to 35°S extends a ridge through Victoria and then along the New South Wales and Queensland coasts. The belt of westerlies south of 40°S and has Tasmania facing a series of weak fronts in this westerly regime. Northern Australian is currently under a slight infeed of tropical moisture.  The upper low has weakened over inland Australia and become absorbed into the trough.

Discussion:  The high will migrate only slowly east through the next day or so, while maintaining the ridge along the east coast. This will ensure the continuation of a moist southeasterly onshore flow bringing showers to coastal areas in particular, but also feeding further moisture into the inland trough. The northern part of the surface trough will move slightly west through Sunday over Queensland, further away from the coast. The upper trough is moving only very slowly east.

Areas to watch: Widespread convective activity within the trough, mainly over northern and northeastern New South Wales and south-central and southeast Queensland, is a possibility during Sunday.

Rainfall potential
Victoria: Isolated showers and drizzle along the coast and ranges, clearing.   Fine and sunny over the northern plains after a cold start with frosts, some severe.
NSW: Cool with showers along much of the coast, with some briefly heavy falls possible.  Scattered showers with isolated storms, mainly along the coast north of the Illawara and in the northeast and north.  Mostly fine west of the Divide. Drizzle on the Alps clearing.
Queensland:  Scattered showers along the coast.  Showers and isolated storms possible in the south and southeast during Sunday.  Cloudy over much of the interior, but little if any precipitation.
NT: Isolated showers likely along the northeast coast.  Patchy cloud in the south, but no precipitation likely to reach the ground.
WA: Mainly fine throughout with only isolated drizzle patches along the southeast coast in a moist onshore flow.
SA:  Mainly fine except for isolated showers along the coast, and with light winds throughout.  Early fogs, mainly in the southeast.
Tasmania: Showers and drizzle over the west and south, mainly fine for the rest of the state after early fogs, with light frost patches.

17 . Overview: The baric ridge lies near to 35°S with the stronger centre remaining over the west of our region.   The centre over eastern Australia extends a ridge along the Queensland coast. Pressures over northern Australia are beginning to show signs of an general decline at the moment with a more evident trough over inland Queensland.  A trough lies through Bass Strait.  The upper cold pool remains slow moving over western South Australia within the trough currently moving east.

Discussion:  During Saturday, the western section of the baric ridge will strengthen with the high over eastern Australia being absorbed into this. A weak upper trough will move through southeastern Australia but will remain largely inactive. The trough through Queensland looks to deepen and extend its influence further south into northwestern New South Wales.   A very deep low of 939hPa in the Southern Ocean extends a front to its north which looks likely to affect southwest Western Australia during the latter part of Sunday.

Rainfall potential
Victoria:  Drizzle patches in the south.  A fine day in the north after a cold start. Mainly fine (ie: little if any precipitation)
NSW: Mainly fine through much of the state with light winds.  Isolated coastal showers in a moist southerly flow.  Patchy cloud in northern inland districts associated with the deepening trough.  Showers with the chance of a storm in this area.
Queensland:  A deepening trough through the inland. Scattered showers within this area. Scattered showers along the coast, more prevalent in the north.
NT: Fine in the north.  Patchy cloud in the south with the chance of an isolated shower mostly not reaching the ground.
WA: Fine throughout with the exception of isolated coastal showers in the south along the coast, clearing through the day.
SA:  Mostly fine with isolated showers along the southern coast. Little if no precipitation reaching the ground in the north.
Tasmania:  Cool and cloudy with patchy drizzle mainly in the west and south. Drizzle less frequent in the northeast.
15 . Overview: A slow moving high pressure system has crawled across southeastern Australia during Thursday and maintains the ridge to the southeast under the low in the Tasman Sea to a high near to 60°S southeast of New Zealand. The Tasman low has continued to direct moist southerlies along the east coast with resulting showers through the day. The low south of the Bight (955hPa at 10amAEST) extends a trough and front to Western Australia, with the wave low now located in the Goldfields tracking recently to the ENE.  A midlevel cold pool is associated with this area. A broken cloudline extending from the Coral Sea across northern Australia has moved southward during the day - high cloud with no precipitation.

Discussion:  The high over southeastern Australia will move eastwards slowly and weaken, becoming absorbed westward into the dominant area of high pressure moving through our longitudes. The West Australian trough, with the wave low,  will move generally eastwards, although the direction of movement of the wave low in particular should be monitored.  The cold pool associated with the surface feature is likely to permit isolated storms to develop. The front approaching southeastern Australia looks to weaken as it progresses east, and it not likely to produce any significant amounts of precipitation. Showers are likely along the Queensland coast again during Friday.

Rainfall potential
Victoria:  A cold night in areas under clear skies, with frosts, mainly in the north and along the ranges, some severe. A fine and cool day with cloud along the ranges.
NSW: A cold night inland with scattered frosts, some severe. Drizzle over mountain areas in the south with scattered showers along the coast, mainly in the north. Cool.
Queensland:  Showers along the coast.  Dry inland.  Frosts over the parts of the southeast.
NT: Patchy high cloud.  Fine throughout.
WA: Fine in the north with some patchy high cloud about the Kimberley.  Showers in the southeast associated with a trough moving through the south of the state.  Chance of a storm.   Showers along the south coast.
SA:  A cold night with frosts in the southeast.  Mainly fine throughout with only isolated showers, falling as virga and mainly not reaching the ground associated with the trough and upper cold pool.
Tasmania:  Cloudy with drizzle and showers, tending to rain periods in the south and west.  Mainly fine in the north and east after a cold night.  Snow showers over higher parts.
14 . Overview: The high in the Bight continues to ridge to the southeast beneath the deepening low in the Tasman Sea. A deep moist southerly flow over the southeastern states has keep conditions unstable through Tuesday with showers over southern Victoria and Tasmania, and snow over the alpine areas with the best falls over the past 2 days over the southern resorts. The high ridging in over southern Western Australia is bringing fine weather to most of the western half of the country. A deep low (935hPa at 10am) and frontal system is approaching from the far southwest and can be identified by the strong convection to the southwest of the continent..

Discussion:  A band of showers with rain periods and isolated storms will cross the southern part of Western Australia during Wednesday.  This low and frontal system is associated with another 'negative longitudinal' (ie: aligned NW - SE ) upper trough.  There are signs of vorticity (most likely to be satellite lows) associated with this system. The high will move slowly through the eastern Bight near to the coast strengthening steadily as it moves east. A further high will ridge in to Western Australia later Wednesday / early Thursday, and may shift northwards as the longwave trough approaches. The low in the Tasman Sea will continue to deepen as it moves towards New Zealand.

Rainfall potential
Victoria:  Scattered showers continuing in the south, mainly fine in the north with overnight frosts. Occasional light snow over the higher peaks.
NSW:  Showers will continue over the south of the state, falling as snow, the snowline will rise slowly over the next day or two.  Showers are also likely along much of the coast and adjacent ranges.
Queensland: Scattered showers, mainly north of 20°S.  Mainly fine elsewhere.
NT: Mainly fine throughout with occasional cloudy periods along the Top End coast.
WA:  Fine in the north. A cold night away from the coast in the south. Scattered showers developing in the southwest during Wednesday, with more widespread showers and storms developing at night.
SA:  Showers over exposed coasts, a cold night inland under clear skies with only light winds.  Showers in the south clearing through Wednesday.
Tasmania:  Cold.   Scattered showers falling as snow over higher areas at first.  A cold night in the east and northeast. Becoming fine later.
13 . Overview: A low is currently located to the southeast of Tasmania while the high over the western Bight sends a ridge to the southeast, creating a cutoff situation. This low has been very slow moving through Monday, while an upper cold pool moved across the southeast of the country bringing snow to the central ranges of Victoria and the Otways, hail to southeast South Australia and snow and sleet to Canberra and as far north as the Central Tablelands of New South Wales.

Discussion: Further cold air in the mid-levels will move over the southeast during Tuesday from the Southern Ocean, continuing the cold and wintery conditions experienced over southeastern Australia during Monday. The high over the western Bight will remain slow moving through the Bight and will maintain the ridge south of the low which will deepen as it moves east through the Tasman.  Another pair of deep lows (954hPa & 956hPa) associated with the next upper trough is located well to the southwest of Western Australia.

Rainfall potential
Victoria:  Widespread showers, with some heavy falls and hail, mainly in the south, central and alpine areas Monday night, falling as snow above ~700m.  Cold southwest to southerly winds over exposed places and higher parts.  Showery with the chance of thunder and hail, mainly in the south, becoming less frequent in the west Tuesday.  Snow showers continuing over alpine areas.
NSW:  Showers continuing in the south and along the coast, falling as snow over the alpine regions and as far north as the Central Tablelands at first, before becoming confined to the southeast corner and along the coastal fringe as far north as the central coast. Cold south to southwesterly winds.
Queensland: Showers along the central and northern east coast and over Cape York.  Mainly fine elsewhere.
NT:  Patchy cloud over the northeast with the chance of a shower.  Fine elsewhere.
WA:  Fine over much of the state with only isolated showers over the southwest corner.
SA:  Mainly fine in the north.  Isolated showers along the coast in an unstable south to southwesterly flow.  Scattered showers over the southeast.   Becoming fine from the west through Tuesday.
Tasmania:  Generally southerly winds with showers and snow particularly in the south and west, extending to low levels (~700m) Monday night and through Tuesday. Chance of a storm and hail.
12 Jane ONeill Nice cold pool crossing the coast near Mt Gambier this morning and there has already been some low level glaciation near Melbourne.   The day looks to get more interesting with a drop in the 500hPa temperature from -25C to -34C between last night & this morning.  Mt Gambier's 500hPa temperature dropped from -20C to -33.5C in the 24hours between yesterday morning & this morning!!!!!  (a change of this magnitude made me check twice to make sure I was reading the skew-t correctly! - might be a bit unstable today!
12 Clyve Herbert Snow has been falling down to 400m over the southwest of Victoria this morning, snow has also been reported from Bambra in the Otway range elevation about 320m. There is a small cold pool vorticity area over the south west of the state, the thermal trough looks to be very cold and appears it will pass across the central region of  Victoria around midday, with a bit of luck some of this cold air may get into Blue Mountains tonight and Tuesday, looks good in Tasmania too.
12 . Overview: The baric ridge has strengthened slightly and remains near to 30°S.  The upper trough extends from south of  New Zealand through the western Bight with the first surface trough and frontal system passing across the southeast of Australia during Sunday night.   Surface wind direction doesn't shift much with the passage of this front in the south - a satellite low to the northwest of the main low has the southwesterly wind change associated with a trough extending to the northwest, and this is lagging through the western Bight on Sunday night. The thermal (cold) trough in the mid-levels is also to the west. The high ridging into southern Western Australia continues to send a ridge southeast through the Bight.

Discussion: During Monday, the high building over southern Western Australia will strengthen initially, but weaken as it moves steadily east. It will direct an onshore flow onto the southern coastline east of the head of the Bight, bringing widespread showers over much of the coast and adjacent areas.  Interaction between this onshore flow with the colder upper temperatures with the thermal trough, and generally unstable and showery conditions are likely to prevail across much of the south of the continent and Tasmania during the next day or two.

The front crossing New South Wales will continue to weaken through Monday, with scattered showers likely with its passage, mainly in the south, falling as snow over the Alps. Showers are again likely along the Queensland coast and adjacent ranges, with patchy cloud over the northeast of the Top End.  Mainly fine elsewhere north of the baric ridge.

Areas to watch: An area of vorticity west of Tasmania looks to move towards Bass Strait as it circulates around the upper trough.

Rainfall potential
Victoria:  Strengthening northwesterly winds, shifting southwesterly during Monday.  Showers, mainly in the south and on the ranges, with isolated storms in the southwest on Sunday night becoming scattered mainly south of the ranges during Monday.  Snow showers over higher parts, extending to lower levels later Monday as the thermal trough moves across the state.
NSW:  The front will move through most of New South Wales by late Monday, but will weaken as it moves east.  Winds will begin to shift to the southwest through Monday.  Showers over the south of the state with the front, falling as snow over the ranges.  Strong northwest winds shifting to southwesterly. Conditions will be significantly colder during the next two days or so, especially in the south.
Queensland: Mainly fine except for showers along the east coast and over Cape York.
NT:  Fine with patchy cloud over the northern Top End.  Isolated showers over the northeast.
WA:  Fine in the north.  Cold nights in the south, but mainly fine, except for isolated showers over the southwest corner.
SA:  Coastal showers. mainly in the southeast with the chance of a storm.   Cooler conditions becoming general in the south.
Tasmania:  Strengthening northwesterly winds shifting southerly.   Generally showery in the west and south, with possible storms, becoming more widespread throughout during Monday.  Showers falling as snow over higher parts, extending to low levels at times, mainly in the west and south.
11 . Overview: The baric ridge remains near to 30°S from the Tasman Sea to the Indian Ocean, interrupted by the trough and frontal system currently moving through South Australia.  The high in the Tasman sends a ridge along the coast of Queensland, while the high over the Indian Ocean west of the continent ridges to the southeast beneath the low. There has been a gradual moisture buildup along the Queensland coast during the past 48 hours. a progression of westward moving NACL's (North Australia Cloud Line) through the northern Gulf of Carpentaria towards the northeast of the Top End.

Discussion:  The upper longwave trough remains aligned negative longitudinally (NW - SE). The trough and frontal system will move through eastern Australia during Sunday.  Warm advection at the 850hPa level (1500m) will mix down to the surface to give milder temperatures ahead of the front.

Following the front, a thermal (cold) trough will bring further unsettled weather to southern coastal Australia with the chance of storms, with snow redeveloping over the resorts on the mainland and  Tasmania (to moderately low levels in the latter). The high moving into our longitudes will drag the baric ridge a little south, and will strengthen the ridge to southeast.

Areas to watch: An area of vorticity in the western Bight may deepen into a satellite low during Saturday night / Sunday and move towards Bass Strait around the upper trough.

Over the past few days there has been a progression of westward moving NACL's (North Australia Cloud Lines) through the northern Gulf of Carpentaria and Arafura Sea towards and past the northeast of the Top End. Watch this image for a narrow cloudline aligned NW-SE.

Rainfall potential
Victoria:  Strengthening winds ahead of the passage of the front during Sunday.  Showers, tending to patchy rain at times, with the chance of a storm especially in the southwest. Snow showers redeveloping following the front.
NSW:  Strengthening winds in the south of the state with showers developing and tending to patchy rain with the passage of the front, except over the alpine areas where snow will redevelop. Remaining fine and very mild (for August) in the north till later.
Queensland: Showers along the east coast, mainly north of Rockhampton and over Cape York.
NT:  Mainly fine except for the northeast coast.  Areas of patchy cloud over the northeast and western Top End coasts.
WA:  Fine in the north.  Showers contracting to the south following the front.  Light showers in the Eucla, moving east out of the state early Sunday.  Colder conditions in the southwest, with possible hail.
SA:  Showers in the south of the state developing Saturday night and contracting to the southeast of the state by Sunday morning.
Tasmania:  Generally showery through the west of the state, becoming more general with periods of rain, with some heavy falls and snow redeveloping over higher parts. Winds shifting southwest to southerly through Sunday, with possible snowfalls to lower levels later.
10 . Overview: The high, which has been slow moving over the past day or two remains over eastern Australia. The axis of the upper trough (which is lying further to the west in the north), is crossing the southwest  Western Australian coast during Friday night.  This lies west of the surface trough and frontal system which continues to source some moisture from the sub-tropical Indian Ocean.  A sharp east-west temperature gradient lies ahead of this system with warm advection bringing milder conditions to the east of the front. The baric ridge lies just south of  30°S, and the baric trough has also moved south.  The high to the west of the continent continues to ridge south and then east, helping to steer the low in a more easterly than southeasterly direction.

Discussion:  The cloudband associated with the surface front and trough will continue to thicken as the system moves east.  Light patchy rain is likely over southern parts of the continent during the weekend (Saturday in South Australia and later Saturday and Sunday in the southeast of the country) with this system which is likely to remain slow moving. The thermal trough (cold trough ~500hPa) will cross the southwest of Western Australia and trigger some heavy showers and possible storms Friday night and into Saturday.

A ridge developing along the Queensland coast will direct a moist onshore flow onto the coast with showers likely mainly north of the Fraser Island. Inland parts of the continent away from the east coast are likely to remain dry.

Areas to Watch: The area of cloud moving through southeastern Australia on Friday afternoon and evening is curious.   Just worth keeping an eye on - for something might just happen.......

Rainfall potential
Victoria:  Northwesterly winds. Mild after a cold night in the east.   Cloud increasing from the west.  Highland fog over exposed slopes on the Alps later.
NSW:  Mainly fine and warm over much of the state.  Cloud developing in the southwest and highland fog over the windward slopes of the Alps. Showers over the Alps developing late Saturday and into Sunday, falling as snow later  in the period.
Queensland: Showers along the coast north of Fraser Island, extending inland to the ranges at times.  Mainly fine elsewhere.
NT:  Fine with the chance of an isolated shower over the northeast.
WA:  Fine in the north.  Possible showers over the Pilbara and extending southeast through the Goldfields to the Eucla.  Showers in the far southwest redeveloping during Friday night and Saturday with the chance of storms.
SA:  Northwesterly winds strengthening and cloud increasing in the west.   Mild. Showers tending to patchy rain developing with the trough and frontal system, crossing much of the state during Saturday.
Tasmania:  Northwesterly winds tending westerly through the day. Showers in the west extending east later in the day.

9 . Overview: The prefrontal trough crossing the west and south of Western Australia is bringing widespread scattered showers to the area.  The high still dominates weather over most of the eastern half of the country with a patch of moisture becoming apparent north of the Top End in the Arafura Sea. A moist onshore flow over the southeast has brought extensive cloud but only few showers, except along the southwest Victorian and western Tasmanian coasts during Thursday.

Discussion:  The slow moving high will continue to edge through southern New South Wales during Friday.  The low and frontal system approaching Western Australia will deepen and move through the western Bight during Friday.  This is associated with a deepening upper longwave trough. Moist infeed from the Indian Ocean will increase the available moisture within the trough and widespread showers tending to rain periods with isolated storms and occasional heavy falls. Northwesterly winds will strengthen ahead of the approaching trough and warm advection will bring milder conditions to the south and east during the next day to two.The high approaching the west of the continent is ridging to the south rather than the east, and will help to cradle the low and steer it east through our latitudes rather than allowing it to move southeast.

Areas to Watch: There is a good chance that the low moving through the Bight will become cut off later Friday.  This system looks to be very slow moving as the upper flow becomes more meridional through the rest of the week.

Rainfall potential
Victoria:  Scattered cloud in the far southwest developing later Friday.   Mild conditions with a strengthening northwesterly winds after a cool night in the north with scattered frost and fog patches.
NSW:  Fine after a cold night inland with frosts and occasional fogs clearing to a mainly fine day, although it is likely to be cloudy in the south over the ranges.
Queensland: Mainly fine in the south with isolated showers along the northeastern tropical coast and Cape York. Patchy high cloud moving into the southwest of the state.
NT:  Mainly fine with the chance of an isolated shower about the northeast coast.
WA:  Remaining fine in the far north. Widespread showers through Thursday night through the west and south of the state, tending to rain periods with occasional storms and possible heavy falls. The passage of the front late Thursday and into Friday will bring colder conditions with continuing showers, isolated storms and possible hail. Falls in the east will be lighter as the system moves towards South Australia.
SA:  Increasing cloud in the west.  Mainly fine with scattered fogs in the north and east overnight.
Tasmania:  Showers in the southwesterly flow overnight, mainly in the west and south and over the higher parts.  Clearing Friday.  Strengthening northwesterly winds.
8 . Overview: The high over South Australia has moved only slowly through Wednesday, and the baric ridge has moved southward to lie between  25°S and 35°S.  A series of fronts crossed southern Australia during Wednesday, while a further more active trough and frontal system approaches Western Australia. The baroclinic cloud patch remains an upper feature ahead of this western system marking the presence of a weak upper trough. . Cooler air has become established over much of southeastern Australia with a buildup of moisture in the lower levels leading to widely scattered showers during the day.  Some early snow fell over the peaks.  Conditions remained mainly fine in the north of the country.

Discussion:  The high will edge only very slowly east through Thursday, becoming the dominant feature of our weather over eastern Australia for at least the next 24 hours or so. The active trough and frontal system will bring widespread showers to the Western Australia late Thursday.

Warm advection ahead of this system will bring milder conditions to the south of the continent during the next couple of days as the frontal system progresses east.  The upper flow looks likely to become more meridional over the next few days, with lower pressures likely to penetrate further north onto the southern part of the Australian continent into the weekend.

Rainfall potential
Victoria:  Scattered showers or drizzle along the coast and ranges, mostly clearing through Thursday.  Mainly fine north of the ranges.
NSW:  Widespread frost & fog patches inland Thursday morning after a cold night. Highland fog & drizzle over the Alps.  Mainly fine elsewhere.
Queensland: mainly fine throughout with only  the chance of an isolated shower over the tip of Cape York early, with an increasing chance of showers along the northeastern coast later.
NT:  Fine.
WA:  Fine in the north.  Cloud increasing over the west, with scattered showers over much of the west and southwest developing as the front approaches.   Possible storms with the passage of the front, mainly in the south, with some heavy falls.
SA:  Scattered showers along the coast with frost patches inland.  Mainly fine over much of the state with only the risk of an isolated shower later along the coast.
Tasmania:  Scattered showers in the west with occasional light snow flurries over higher parts.  Clearing temporarily, then light showers or drizzle redeveloping, mainly in the west and north.
7 . Overview: The baric ridge has re-established across the continent near to 30deg S with the highest pressure over southern South Australia. The area of vorticity that developed to the west of Tasmania last night has progressed east into the Tasman Sea as a deepening trough, while a series of fronts is moving through the Bight south of the baric ridge. Satellite lows are moving around the western and northern side of a low of 964hPa in the southern Bight. The cloudband associated with the passage of the trough and frontal system across New South Wales has weakened through Tuesday - earlier today, the cloudband was broken over the Alpine region over the southeast of the continent before reforming to its east. A cloudline over the Arafura Sea near to the Top End marks the presence of moist convergence in the area, with a large area of moisture evident in the convection over Papua New Guinea.

Discussion:  The high will consolidate into one major centre over eastern South Australia during Wednesday and strengthen.  Fronts will continue to move south of this high affecting the southern parts of the continent and Tasmania. A baroclinic cloud streak that has developed over the northwest of Australia during Tuesday afternoon will move through Western Australia during Wednesday with the cloud streak possibly becoming more substantial as it moves east with the jet, with a further area to its south as noted in the Areas to Watch section below.

A series of fronts moving through the southeast Tuesday night and Wednesday will bring widespread showers, tending to patchy rain over the area. A deep west to southwesterly flow will become established over the southeast.  The band of high cloud over northeastern New South Wales on Tuesday night will have cleared the state by Wednesday, resulting in mainly fine conditions in the north of the state.  Showers are likely over Cape York while the rest of northern Australia should remain fine.

Areas to watch: Another, larger baroclinic area is evident over the Indian Ocean to the west of Australia near to 30S and is responding to a strengthening jet.  This is looking to cross the coast between Geraldton and Northwest Cape later Wednesday or Thursday and may bring general patchy light rain to the west.

Rainfall potential
Victoria:  Showers in the southwest.  Snowfalls over the Alps early, then clearing and leaving highland fog.  Mainly fine elsewhere. Strong to galeforce west to southwesterly winds will ease through the day.
NSW:  Showers clearing over most of the state except in the south over the Alps, where snowfalls are again likely early before clearing.
Queensland: Mainly fine except over Cape York where there are likely to be isolated showers, and then mainly on the eastern side.
NT:  Fine throughout.
WA:  Mainly fine except along the southern coasts where there will be early showers before they contract to the southwest.  Isolated light falls are possible from middle level cloud over the Pilbara, probably not reaching the ground.
SA:  Isolated coastal showers.  Fine elsewhere after a cold morning away from the coast.  Mainly fine.
Tasmania:  Showers over the western half, with strengthening west to southwesterly winds.  Snowfalls developing over higher parts.
6 . Overview: The low over the Tasman Sea is beginning to weaken and fill in, while the weakening high over eastern Australia is being nudged eastward by the approaching frontal system. Strengthening winds ahead of the front have caused minor damage in South Australia tonight.  A front is moving through the Bight with a mid-level trough following.  Winds are strengthening well ahead of this front. Infeed from the Indian Ocean into this system is still apparent, although it is now quite weak. The next high is ridging in to the west near to 30°S.

Discussion:  A stronger high will move across central Australia during Tuesday, remaining near to 30°S and re-establishing the baric ridge across the continent.  A series of fronts will move across the southern parts of the continent and Tasmania Tuesday to the south of these highs. The mid-level cold trough in the Bight Monday night will move through southeastern Australia during Tuesday and be accompanied by strong winds and generally showery conditions with snow over the higher parts of the Alps.

Conditions over Australia north of the baric ridge should remain mainly fine except for isolated showers over parts of Cape York.

Rainfall potential
Victoria:  Strengthening north to northwesterly winds Monday night, reaching galeforce at times, overcast with only scattered showers.  Areas of light rain in the west early Tuesday, spreading east with the front.  Isolated storms are possible, mainly on and south of the ranges.  Showers becoming less frequent in the west through Tuesday. Snow showers developing over the Alpine areas later Tuesday and extending down to near 1200m at times.
NSW:  The front will cross much of the state by Tuesday night, swinging milder north to northwesterly winds to the west or southwest.  Colder conditions to follow in the south, with snow falls over the Alps extending down to 1200m. Remaining mainly fine in the northeast.
Queensland: Mainly fine except for isolated showers over Cape York, mainly on the east.
NT:  Mainly fine throughout.
WA:  Fine in the north.  Showers along the south and lower western coasts contracting to the southwest during Tuesday.
SA:  Strengthening northwesterly winds to galeforce at times on Monday night, mainly in the south.  Patchy rain overnight Monday with isolated storms, particularly in the southeast, easing to showers during Tuesday and then clearing from the west.
Tasmania:  Strengthening northwesterly winds ahead of the front, reaching galeforce at times. Showers in the west, tending to rain periods.  Isolated storms possible. Scattered showers through the east of the state.
5 . Overview: The low that moved across southeastern Australia during Saturday has continued to deepen and is well off the coast by Sunday night. A high is positioned over New South Wales and ridges southward, most likely a result of its position between the low in the Tasman and the approaching frontal system in the Bight. The trough and front moving across Western Australia during Sunday extends from a low in the southwestern Bight (968hPa) near 50°S with a satellite low to its north looking to develop near 40°S. (like last week....)

The moisture plume crossing Western Australia has its origins near Taiwan (25°N) and is feeding into a deepening trough ahead of the front in the west.  Convection over the northeast Coral Sea has dissipated and is being sheared to the southeast and may be dragged into the circulation of the low currently moving through the Tasman.

Discussion:  The high will strengthen slightly as it moves through New South Wales during Monday, with the ridge to the south only slowly moving across Victoria and Tasmania, while to the west and southwest of this ridge, northwesterly winds will strengthen as the pressure gradient steepens ahead of the approaching front. A satellite low may develop over the Bight  in response to the interaction between the upper trough and the subtropical jet.

Showers associated with the thermal trough to the west of the cold front along the southern coast of Western Australia are likely to continue through Monday. The next high is ridging into the west close to 30°S.  The northern part of the continent should remain mainly fine throughout.

Areas to watch: The trough moving across Australia should be watched for further intensification of the moisture plume and associated cloudband with the possible development of upper vorticity during Monday, most likely over the Bight.

Rainfall potential
Victoria:  Cloud developing in the west and spreading throughout during Monday.  Strengthening northwesterly winds.  Showers developing in the southwest late in the day or early Tuesday.
NSW:  Mainly fine with scattered frosts and fog patches, particularly in the south.
Queensland: Mainly fine except for isolated showers over the very northern tip of Cape York.
NT:  Mainly fine throughout.
WA:  Fine in the north.  Patchy light rain from the cloudband across the central west and through the Goldfields.  Showers continuing in the southwest with isolated storms.
SA:  Increasing cloud in the west with showers developing and extending east through the day.  Scattered showers remaining in the south behind the front.
Tasmania:  Mainly fine after a cool night.  Showers developing in the west later.  Strengthening northwesterly winds.
4 . Overview: A complex area of low pressure developed over southeastern Australia during Saturday as a function of the amplification of the trough over our longitudes. A trough extends northward and is moving towards the coast on Saturday night. A moderate strength high is located over South Australia near to the head of the Bight. A trough and cold front is approaching Tasmania and a cold front is also approaching the southwest of Western Australia.

The lows in the Southern Ocean are edging northward again, and this will help to maintain the position of the baric ridge across the continent near to 30°S. The mid level baroclinic cloud area is expanding as it makes landfall over Western Australia  as tropical moisture continues to feed in from the area to the southwest of Indonesia.

Discussion: The surface low will continue to move east into the Tasman Sea and deepen through Sunday, and showers and storms will contract to off the coast during Sunday. The high will move into New South Wales and maintain its position near to 30°S, with a series of fronts following to its west and crossing southern Western Australia during Sunday.

Moisture from convection over the northeast Coral Sea will (as during much of last season) move into the 'shear zone' through the Coral Sea and move away to the southeast.

Areas to watch: The baroclinic cloud patch covering much of Western Australia and marking a deepening upper trough, should be monitored as it moves towards eastern Australia.

Rainfall potential
Victoria:  Showers continuing over the northeast and along the southwest coast (tonight for the southwest only), with isolated storms in the northeast and possible hail.  Snow flurries over the higher peaks tonight and early tomorrow, becoming isolated.
NSW:  Showers and storms will move eastward during Sunday as the low moves away to the east.  Showers continuing over the south and central coasts with showers continuing over the exposed parts of the southern ranges, falling as snow over the higher peaks.
Queensland: Isoalted showers over the northern parts of Cape York.   Possible showers and storms on Saturday night and into Sunday morning in the southeast as the trough moves off the coast.  Fine elsewhere.
NT:  Fine throughout.  Occasional cloud patches in the northwest near the coast.
WA:  Showers becoming widespread over much of the southern and central western parts of the state with a cold front interacting with the trough (as marked by the baroclinic cloud area).  Isoalted storms later in the south and southwest in a cold unstable onshore flow.
SA:  Showers contracting to the southeast and clearing.  A cold night under the influence of the high with a mainly sunny day.  Cloud increasing in the far west later.
Tasmania:  Scattered showers and isolated storms in the west and north, becoming isolated through Sunday.  A cold night in areas under clear skies.
3 Jane ONeill TORNADO Images from Euroa tornado Saturday 3rd August
3 . Overview: The baric ridge remains temporarily interrupted by troughing over eastern Australia on Friday. Scattered storms (some with hail) were reported over parts of southeastern Australia Thursday night and continuing during Friday. A deepening low to the south of Tasmania extends a trough into the Tasman Sea, while a low near to 60°S (977hPa at 10am AEST) extends a front north to the head of the Bight ahead of a significant cold air field associated with an upper trough.

A ridge of high pressure extends along the Queensland coast.  An upper level moisture plume is evident in the Indian Ocean extending from an area of convection southwest of Sumatra (same origin as the last plume), while a rather strong surface high in the Indian Ocean sends a ridge into Western Australia.

Discussion: The trough in the Tasman Sea is likely to deepen further during Saturday as it moves east. The area of vorticity located in the Bight near to 37°S is moving northeast towards the southeast of the continent and has a cold pool associated also in the middle levels. This amplification of the trough will help to further destabilise conditions in southeastern Australia during Saturday, with further storms, as well as snowfalls developing over the Alps likely as this system moves eastward, probably close to southern Victoria.

Increasing moisture levels are likely over the Top End as an area of tropical moisture moves south over the Arafura Sea. The ridge of high pressure in the west will 'bud off' a new centre and this will begin to edge further east towards South Australia later Saturday, but a low and front to its west will again interrupt the baric ridge across the continent.

Areas to watch: The area of vorticity in the northeastern Bight Friday night looks likely to develop into a low and move east through or near southern Victoria on Saturday. The moisture plume (baroclinic area) approaching from the Indian Ocean should be watched for further development as it moves across the continent.

Rainfall potential
Victoria:  Patchy rain continuing in the north Friday night, with scattered showers over much of the state during Saturday, with isolated storms & further hail likely as the colder air becomes established.  Showers falling as snow over the Alps.
NSW:  Widespread showers and thunderstorms within the trough moving through the state on Friday night, with the passage of a front on Saturday triggering further showers, falling as snow over the Alps and further north towards the Central Tablelands, with storms once again likely.
Queensland: Isolated showers over the northern tropical coast and Cape York. Chance of showers and isolated storms developing over the southeast corner and along the ranges. A cloud streak identifies the location of the upper jet.
NT:  Moisture levels increasing over the Top End with possible showers along the north coast, mainly in the northeast.  Fine elsewhere.
WA:  Fine in the north with some high cloud developing over the west with patchy light rain developing.  Scattered showers in the southeast as well as light showers in the southwest corner.
SA:  Widespread showers with scattered storms and locally heavy falls in the south particularly in the southeast on Friday night and into Saturday. Showers over the southern coastal regions persisting in the southwesterly flow. Hail in the south possible.   Colder conditions developing.
Tasmania:  Cold tonight with frost patches.  Showers in the west & north, tending to patchy rain with isolated storms.
2 . Overview: The baric ridge across southern Australia has been interrupted by a rather complex trough situation over eastern and central Australia. A low south of Tasmania extends a weakening cold front and trough north through the southeastern states, while over Queensland a midlevel trough is also triggering storms through the southern and central parts of the state. To the west through southern Western Australia, another front and trough is triggering showers and isolated storms, while between these troughs is a very weak area of high pressure with an overlying almost stationary baroclinic cloud patch marking an upper trough.  A large midlevel cold air field covers the Bight and is drifting over the southern parts of the continent serving to destabilise the situation even further. Complicated!!

Discussion: The low south of Tasmania will deepen as it drifts southeast, while another satellite low will move northeast around the trough in the Bight during Friday. Colder air in the middle levels and increasing moisture will steadily penetrate the south and east of the continent during the next day or two. The high in the Indian Ocean will ridge towards Western Australia, but there will be no strong high pressure control over the continent for the next day or two - we will be dominated more by lower pressures generally than we have seen in the southeast for a while.

Areas to watch: The baroclinic cloud patch over South Australia should be monitored for the next 24 hours - there is a chance that it may move toward southeastern Australia and interact with a mid level cold pool moving up to the area from the Bight.

Rainfall potential
Victoria:  Scattered showers and storms across the state, mainly in the northeast and central parts, associated with the trough on Thursday night. Unsettled conditions throughout are likely to continue through Friday, with snow falling on the Alps.  There is potential for some good falls from this system.
NSW:  Widespread scattered showers developing, with isolated storms in the far south and northern border areas moving generally east with the trough.  Northwesterly winds strengthening Friday with showers on the ranges falling as snow over the Alps.
Queensland: Scattered showers and isolated storms mainly in the southeast of the state, moving east through Friday towards the coast.
NT: Patchy cloud over the northeast with a shower or two.  Fine elsewhere, morning fogs along coastal areas. Note: Darwin 'stormcam' is no longer in existence.
WA:  Fine in the north, patchy cloud in central areas, only isolated midlevel showers.  Scattered showers and isolated storms in the south and southeast moving east. Showers remaining along the south coast in a moist flow ahead of a high building in.
SA:  Patchy rain in the central and northeast on Thursday night, moving east with the trough through Friday.  Cloud building in the west with the next approaching front.  Isolated storms mainly in the south, with patchy rain redeveloping later Friday.
Tasmania:  Strengthening northwest to northerly winds during Friday.  Widespread showers developing in the west and north tending to rain periods before clearing temporarily. Snow developing over higher parts.
1 . Overview: A strong high near New Zealand extends a ridge through New South Wales and into the Northern Territory with a  weaker ridge located along the Queensland coast. A trough and cold front are west of the ridge passing through South Australia on Wednesday night and triggering storms in the southeast of the state. A weak 'satellite' low is located west of Tasmania in the central Bight and is currently moving northeast.  The high to the west is ridging only slowly (and somewhat weakly) along the southern coast of Western Australia.  A moisture plume from the Indian Ocean is feeding onto the continent near to Shark Bay to Northwest Cape.

Discussion: The baric ridge will re-establish across the continent between Perth and southeastern Australia, with a series of fronts crossing the Bight and southern parts of the continent, however there is a mid level trough developing as evidenced by the moisture plume over Western Australia. The satellite low in the Bight will travel around the northern edge of the trough currently moving through the Bight and affect Tasmania during Thursday, while the trough and front will cross the southeast of the continent.

The trough in the Tasman Sea looks to become disorganised as it moves east.

Areas to watch: The plume of moisture (baroclinic area) moving onto the continent from the Indian Ocean originates from an area of strong convection to the southeast of Sumatra, and its eastward progress and further development should be watched over the next 24 hours.

Rainfall potential
Victoria:  Increasing cloud during Wednesday night and Thursday, strengthening northwesterly winds with showers developing in the west and spreading east.   Scattered showers with light falls across the state, possibly falling as sleet on the higher peaks. Possible isolated storms in the south.
NSW:  Increasing cloud and freshening winds in the southwest of the state on Wednesday night, spreading east through Thursday. Scattered showers developing, with possible sleet over the peaks later Thursday. Remaining fine and mild in the north.
Queensland:  Isolated showers over the northeastern coast and Cape York.   Mainly fine elsewhere except in the southeast where isolated showers may develop later Thursday.
NT: Cloud patches over the northern coast with isolated showers in the northeast.  Mainly fine elsewhere.
WA:  Fine in the north of the state.  Middle level cloud crossing the central and southeastern parts during Wednesday night and Thursday with isolated showers possible. Showers along the south coast triggered by the passage of a front.
SA:  Showers and isolated storms in the southeastern corner Wednesday night, clearing from the west before redeveloping later Thursday and into Friday.
Tasmania:  Showers Wednesday night in the north and west, spreading east through Thursday with a weak front. Possible snowfalls over higher peaks later.
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