October 2002 Forecast Outlook, Discussion & Report Page
Overview: A high is located off the east coast in the southern Coral Sea extending a ridge along the Queensland coast - this high restrengthened after it moved off the land. A weak trough and front is moving across eastern Victoria and New South Wales during Wednesday night and part of this trough will likely to stall in the northeast of New South Wales and eastern Queensland. A ridge of high pressure is following the southern coastline of Western Australia while the west coast trough has deepened further inland of the coast. A west - southwesterly flow has become established over the eastern Bight and Tasmania.
Discussion: The high in the Coral Sea will begin to drift southeast, while the low near to Tasmania will move towards the southern Tasman Sea, setting up a southwesterly flow ahead of the approaching high. The deepening west coast trough will interact with the approaching front from the southwest and begin to move east. Significantly colder air lies to the southwest of the continent. The trough over northeastern New South Wales may lag for the next day or so over the northeast of the state and eastern Queensland, triggering showers and occasional storms, especially near to the coast in a moister environment.
Overview: The high has weakened as it has moved across eastern Australia, and the low in the Bight along with the trough extending through Western Australia has continued a generally easterly movement around the northern edge of the upper trough through Tuesday. The surface high to the west of the continent is ridging in along the southern coast.
Discussion: The surface low will begin to move in a more southeasterly direction during Wednesday and the trough and front will cross the southeast of the continent. Moisture from the Timor Sea and Indian Ocean will continue feeding into the trough over the northwest of the continent. A weak southwesterly flow will follow the front in the south ahead of the high which will move east rather more rapidly in the more zonal upper flow. The west coast trough will begin to deepen along the coast.
Overview: The weakening high in the eastern Bight continues to drift slowly east with a weak trough inland of the Queensland coast and a small low in t the southern Coral Sea atop a trough. The low to the south of Western Australia and the trough through the state continue to also move slowly east triggering storm over the inland. The high ridging in from the Indian Ocean has already started to ridge beneath this low.
Discussion: The high will drift east across eastern Australia during Tuesday with the trough and front following through South Australia with showers and storms triggered in the baroclinic area ahead of the front. The low in the Bight will move a little south of east, but will remain in our latitudes. Again the high from the Indian Ocean will ridge along the southern coast of Western Australia.
Overview: The weakening high in the Bight has moved only slowly through Sunday and has cut the deepening surface trough moving through eastern Queensland off. The cloudband from this system is expanding south along the New South Wales coast. The low and trough over the west coast is moving slowly east, triggering isolated storms within the baroclinic area ahead of this low.
Discussion: The high will continue to weaken as it moves east with the low to the west passing just south of Western Australia during Monday with the trough moving steadily east through the south of the state. The trough lying over Queensland is likely to weaken and become broader and less active, while a weak upper trough moves through New South Wales and into Queensland.
Overview: The trough moving through eastern Australia has deepened as it has moved into a moister environment and has triggered showers and storms over the southeast of Queensland. The high in the Bight is beginning to cut this area off. This trough extends to the Kimberley and has also triggered showers and storms near to the coast in the northwest. The high in the Bight remains slow moving with the surface low and associated upper trough deepening as they move east towards the continent. This surface low remains at lower latitudes than has been the case for a number of months, and is the second in a series of lower-latitude lows to affect the west.
Discussion: The high in the Bight will remain slow moving and will cut the trough off from the westerly flow, leaving it slow moving over southeast and particularly the central coast and hinterland of Queensland. An upper circulation, evident over South Australia on Saturday night will move northeast and is likely to interact with the surface feature over Queensland and may produce some moderate rainfall totals over parts of eastern Australia during Sunday. Moisture is building over tropical Australia. The low to the west will continue to move east between 35°-40°S and interact with the deepening west coast trough.
Areas to watch: the passage of the trough through eastern Queensland, and the movement of the upper low towards it should be monitored for the next 12 - 36 hours.
Overview: A high located in the central Bight is to the southwest of a broad trough currently lying through New South Wales, Queensland and the Northern Territory. A deep low over the Southern Ocean south of Western Australia extends a surface trough northwards to near 25°S west of the continent, with signs of satellite low development within a deepening upper trough. The continent south of the tropics is influenced by a zonal westerly flow at 300hPa (30,000').
Discussion: A southwesterly flow will become established across the southeast during the weekend leading to scattered showers, mainly along the ranges (falling as snow) and in the south. That part of the trough over New South Wales will drift northwards along the coast during Saturday, with the likelihood of some scattered shower and storm activity as it moves into a moister environment, particularly over eastern Queensland. Most of the inland extent of the trough away from the coast will remain largely inactive during the next 24 hours.
To the west, the upper trough and associated surface low will deepen as they move towards the coast with the surface low likely to remain between 30° and 38°S. The high in the Bight looks to remain slow moving through the weekend.
Discussion: The high will drift eastward across the northern Tasman and restrengthen somewhat off the coast, while the trough will move east through the eastern states, reaching the central coast of New South Wales by Friday night. The high in the Bight will strengthen and will move east during the weekend to be east of Tasmania by early in the week. This high is supported by a strong upper high to its northwest. A brief return to chilly nights with the chance of a late frost in the southeast is likely. The west coast trough will slowly deepen just inland of the coastline.
Areas to watch: there are signs of midlevel vorticity southwest of Mt Gambier on Thursday night which should be monitored for further development.
|24||Clyve Herbert||Seems to be some mid level vorticity just southwest of Mt Gambier and moving eastward would be nice for Vic if it became slow moving!? .. a wish forecast maybe.....also not a bad tropical storm over the northeast of the NT it also has unusual upper outflow features.|
A couple of amazing images of the dust
through New South Wales & Queensland......
Discussion: The high in the Bight will move northeast and weaken quickly, becoming absorbed into the generally lower pressures across Australia. The trough and low in the western Bight will move east through Thursday while a strengthening front moving northeast through the Bight is likely to interact with this system bringing further wintery showers, thunder hail and snow to the alpine areas during the latter part of the week.
|23||.||Overview: The low in the
southern Bight has deepened as it has moved east through the day, and the trough extending
northward through Victoria has amplified during the afternoon. This trough is also
bringing significantly colder air to the southeast of Australia from the Southern
Ocean.The north of the continent remains under the influence of broad troughing, while a
very dry atmosphere suppresses convection. A strengthening upper trough continues to move
steadily towards the west coast and western Bight. A moisture plume is feeding in from the
Indian Ocean into the trough over the southwest.
Discussion: The trough and front will move east through Tuesday night and Wednesday, bringing significantly colder conditions to the southeast, widespread showers, the chance of hail and thunder and snowfalls to the alpine areas...Welcome Back Winter! The trough will move through much of the eastern states by Wednesday night.
The low passing south of Tasmania will deepen as it progresses east. The high near to Western Australia, which ridged beneath the low near Perth will continue ridging to the northeast and cradle the low near to the coast. As this low moves east the west coast trough will deepen and interact with the trough to its south. Well to our west, a similar synoptic couplet is moving towards our longitudes, with a low well to the north and a high ridging beneath it.
Areas to watch: There is weak vorticity northwest of Tasmania that should be monitored. The trough in southeastern and eadstern Queensland is worth watching - there is a chance of more moisture coming into that area at lower levels!
|22||.||Overview: The high is
moving over southeastern Australia and weakening rapidly, while almost the entire
continent comes under the influence of a broad area of low pressure. A deep upper
trough and associated complex surface low is approaching Western Australia, bringing with
it a lot of moisture, while the high in the Indian Ocean is ridging southwards under this
Discussion: The trough approaching South Australia and the southeast will steer the high in a northeasterly direction where it will weaken and dissipate within the broad trough of low pressure remaining over eastern Australia. The high in the Indian Ocean will cut the low off near Perth, while a strong front with a marked east-west temperature gradient will cross South Australia and move into Victoria.
The high ridging under the low near Perth will also help set up a strong southwesterly flow across southeastern Australia, bringing a return to rather wintery conditions as far north as the Central Tablelands of New South Wales. Although generally low pressures across the continent, there is little available moisture away from the coast, hence little storm activity in the north of the country.
|21||.||Overview: A slow moving
high has taken up residence in the Bight during the weekend. A complex trough
remains through Queensland, the Territory and to the Kimberley, but the atmosphere is very
dry and the trough remains largely inactive. A low is approaching Western Australia near
to 35°S (a lower latitude than we have seen for a while), while another low is located in
the southwestern Bight. The west coast trough has deepened southward and is pushing
through the ridge. A stream of cirrus marks the location of the upper jet.
Discussion: The trough over Queensland will move only slowly northeast, but conditions will become more moist as air is drawn in from the Coral Sea. The ridge of high pressure will weaken through Monday and begin to move east as the systems to the west move into our longitudes.
A strengthening upper trough to the west of the continent together with the surface low associated with it will approach the west later Monday / Tuesday. The high over the Indian Ocean will ridge beneath the low approaching Western Australia and cut it off from the westerly flow to the south. The west coast trough will likely invade the baric ridge during Monday, with the ridge over southern Western Australia retreating westwards.
|20||.||Overview: The deep low
in the southern Bight is currently passing to the south of Tasmania and extends a trough
through the Tasman, through northeast New South Wales, and across to the Kimberley. Lack
of moisture has this trough being largely inactive. A high is located in the head of the
Bight with a ridge lying across Western Australia. Another deep low and upper trough is
located in the southwestern Bight. A baroclinic cloud patch over southwest Western
Australia has developed through Saturday and also marks a strengthening upper jet over the
Bushfire plumes are evident on both radar & satellite imagery.
Discussion: The low will move eastwards through the southern Tasman Sea while the trough will move only slowly through the northeast corner of New South Wales, Queensland and across the north of the continent, while the northwest part will remain anchored over the Kimberley, forcing the rest of the trough to 'swivel' as the low moves away. The high in the Bight will move only slowly east during Sunday. The combination of a deepening upper trough and approaching tropical moisture may make the next few days rather interesting, particularly over the west of the continent.
|19||..||Overview: A deep low in
the southern Bight extends a complex trough and front through Tasmania and Victoria on
Friday night. The trough can be traced all the way to the Kimberley region, but
there is a serious lack of moisture away from the southern coast - actually, there was a
serious lack of moisture across Victoria. Red rain has fallen over southern Victoria
courtesy of the northwest of the state. The high in the Tasman remains slow moving and
rather weak, while the next high to our west is ridging weakly along the Western
Australian southern coast. A broad westerly flow is located south of the continent.
Discussion: The front will move quickly through the southeast of the country and into the Tasman, while the trough may linger over northeast New South Wales during Saturday. The high ridging into the west will move east near to 35°S with an upper high to the north while the west coast trough will deepen just inland of the coast southwards into the ridge. Colder air in the middle levels is likely to move across Tasmania and Victoria Saturday night and into Sunday as the deep upper trough in the southern Bight moves to the south of Tasmania, with showers, and possibly snow at higher levels.
|18||.||Overview: A weak ridge
lies across southeastern Australia, literally marooned with in a sea of low pressure. Very
high temperatures were recorded in northeast New South Wales ahead of the trough. A trough
is passing along the New South Wales coast. A strong front is crossing Western
Australia (reports of tornadoes!!). A strong west-east temperature gradient at 850hPa is
evident with this front. The 500 - 300hPa flow (18,500 - 30,000') can be located by
tracing the baroclinic cloudband which lies ahead of the front in Western Australia,
through the Bight and being drawn into the trough and into the Tasman.
Discussion: The front will maintain its strength as it progresses east through Friday, with strengthening northwesterly winds. The high will move rapidly as the front moves east. With much of the eastern part of Australia lacking in atmospheric moisture, little shower or storm activity is likely away from the frontal system over the south. Scattered showers and storms are likely with the passage of the front, particularly over the southeast corner. Another weak ridge of high pressure will move along the southern coast of Western Australia.
|17||.||Overview: Weak pressure
gradients over the Australian longitudes are dominant with the baric ridge breaking down
completely. A complex trough moving through the southeast during Wednesday is bringing
mainly light showers, while to the west a satellite low is moving through the Bight with
an upper baroclinic cloudband ahead of a front approaching the southwest of the continent.
A storm on the central coast of Queensland, and Hector over the Tiwi Islands north of
Darwin were the convective activity north of 25°S. Parts of Western Australia and South
Australia, under the influence of an 850hPa heat sink recorded temperatures near the 40s
with virtually no moisture in the air.
Discussion: The trough will continue to move through eastern Australia while a weak ridge will build in from the west during Thursday, but will rapidly be moved into the Tasman by the next approaching trough. A front associated with a deepening upper trough will cross Western Australia during Wednesday, and the interaction with the baroclinic cloudband may lead to some moderate to heavy falls in the southwest in particular. Cyclogenesis is also possible within this area during Thursday.
Much of northern Australia will remain under a general trough of low pressure with occasional storms over southeastern and central Queensland coasts.
Areas to watch: The baroclinic cloud band in the western Bight may be drawn into the trough over southeastern Australia. The direction of movement of the patches of cloud developing within the trough over inland South Australia on Wednesday night are worth watching.
|16||.||Overview: A weak
pressure gradient lies across the continent. The low in the Tasman is continuing to tilt,
with the trough extending through northeastern Queensland continuing to drift slowly east.
A significant amount of moisture from the Indian Ocean has been advected across the
southeast ahead of a trough approaching from South Australia. A front is approaching
Tasmania. A satellite low is passing close to the south coast of Western Australia and is
followed by a deeper low to its southwest. A weak high is approaching the west of the
Discussion: There are signs of possible cyclogenesis during Tuesday night or Wednesday in the eastern Bight. The front in the Bight on Tuesday night will move east and cross Victoria and Tasmania during Wednesday, and the scenario may become further complicated if the satellite low in the Bight begins to catch up with the trough moving through South Australia. The ridge of high pressure to the west will remain weak, with lower pressures remaining dominant. A weak pressure gradient will remain over northern Australia.
|15||.||Overview: The surface
low over Tasmania continues to move only slowly, but is also tilting with a resultant
returning cloud band currently affecting Gippsland and expanding outwards from the low to
affect central and southern parts of Victoria. The high over New Zealand is beginning to
alter its alignment, with the northernmost part moving to the east faster than that in the
south, while a ridge extends west south of the low, cutting it off from the westerly flow.
A weak high sandwiched between this low and the trough is located over the eastern part of Western Australia with another cell just off the west coast near to 25°S (the lowest latitude for a high over these longitudes for quite a while). A broad trough in the southwestern Bight has a series of satellite lows moving northeast and around it. The trough that moved through eastern Australia during the weekend now lies through Queensland.
Discussion: With a ridge to its south, the low over Tasmania is likely to drift generally east during Tuesday following its upper cold pool which remains to its northeast. It is likely that the returning cloudbands across Tasmania and Victoria my produce some reasonable totals before the system moves further to the east.
The high will ride northeast towards Queensland around the top of this low. A front is approaching from the southwest and the trough has begun movingeast through Western Australia. A large amount of moisture, advected from the Indian Ocean is being drawn into our longitudes and this will interact with the trough and frontal system passing through southeastern Australia later in the week.
|14||Clyve Herbert||An interesting cirrus wrap around moving around the cold pool low over Tasmania and coming ashore near Wilson's Prom.|
|13||Clyve Herbert||Not a bad looking cold pool just south of Mt Gambier, this system has a maximum vorticity around 500hpa at around 40 south west of Tasmania and due south of Mt Gamb: and appears to be moving slowly east might kick off some ok cold air CB's across southern Vic and through Tasmania this afternoon|
|12||.||Overview: The high lies
to the southeast of Australia and over Tasmania, ridging along the east coast and into the
Northern Territory,helping to cradle the trough currently located over eastern Australia.
A northeasterly flow has helped to increase the amount of low level moisture over the
eastern part of the continent during the past few days.
The front crossing the Bight has caught the trough moving into South Australia with a high ridging in rather strongly behind it through Western Australia near to 30°S. The low in the Bight, which is associated with a deepening upper trough, is approaching the western side of the high over the southeast, with a corresponding tightening of the pressure gradient and strengthening of northerly winds preceding the trough.
Discussion: The high over Tasmania will slip away to the southeast during Saturday being forced around the western side of the high which is presenting a longitudinal (N-S) boundary. The trough will move through South Australia and into Victoria during Saturday with strengthening north to northwesterly winds. The high to the west will weaken and continue to ridge through southern Western Australia while a strengthening ridge along the east coast, courtesy of the high in the Tasman will slow, if not halt the eastward movement of the trough over eastern Australia, while continuing to direct a moist northeasterly flow across the coast.
Areas to watch: the area of convection near to the Solomons is beginning to to show signs of better organisation.
|11||Clyve Herbert||There appears to be some moisture build up (low to mid level) over eastern QLD and northeast NSW, a weak dry line also exists through east central QLD along a weak surface trough, it will be interesting to see if some of this moisture is advected to the south over the next 24 to 36 hours and interact with the approaching trough through SA.|
|11||Andrew McDonald||It is starting to look nicer with each model run. AVN now has LI's down to -2 to -3. There is going to be some infeed from the NE according to most models which will extend about as far W as a line from Warnambool to Mildura. Between that NE infeed and the trough (W'lys) there is a narrow band of N'lys which is probably there at the moment and is what is most likely preventing anything significant from developing over the land. Once/if the trough can ride into the NE'ly infeed tomorrow, things should start to get a LOT more interesting. Let me just say though that this NE infeed is not overly moist in itself but it should have more moisture than the N'ly. I think where the trough runs into the NE'ly is the place to be. DP's of 8C or more should see storms (PBL DP that is). Given the temps of the lower levels, it should be a late kick off - going by what I've seen I'd be thinking after 3pm.|
|11||.||Overview: An 850hPa
trough over eastern Australia is helping the infeed of moisture into the area, with the
surface trough deepening through Queensland and into New South Wales during the day.
Another trough extends through the Tasman Sea from the South Island of New Zealand,
and also plays a role in the infeed mechanism operating at present. The high has moved
only slowly east from the Bight into Bass Strait to the south of the trough. To the west
of the high the west coast trough has deepened southward and moved east into the
Goldfields of Western Australia ahead of a front crossing the southwest corner of the
Discussion: The trough over eastern Australia looks to weaken slightly through Friday but remain through Queensland and New South Wales. The high will drift slowly towards the Tasman Sea through Friday, with the pressure gradient between the trough over eastern Australia and the trough moving through South Australia becoming steeper, as the more westerly system pushes east. The low pushing east through the Bight will slide southeast along the western edge of the high pressure over the southeast.
This image (courtesy CSIRO) shows a distinct boundary between moist air to the east and dry air to the west over Queensland this afternoon.
|10||.||Overview: The high in
the Bight has remained quasi-stationary through Wednesday and the trough through eastern
Australia which extends into the central Tasman Sea has also moved eastward only slowly.
The high over New Zealand extends a ridge paralleling the Queensland coast just
offshore. Isoalted storms in the northeast of New South Wales and southeast Queensland
during the afternoon - with reports of large hail from Jimboomba (Qld). The west coast
trough has deepened through the day inland from the coast. Moisture from the area of
convection near the Solomon Islands is being held to the northeast by the upper high over
the Coral Sea.
Discussion: The high in the Bight will move very slowly east during Thursday, dependent upon the high over New Zealand moving anywhere (like further east...), although the ridge off the Queensland coast will weaken, allowing the trough to move east at lower latitudes. The trough through Western Australia will deepen and move east, while to its south a front will cross the southwest of the state. The high to the west will begin to ridge into the far west near to 30°S.
The trough over western Queensland is beginning to show signs of more sustained seasonal development, and while the high over the Bight moves east across southern Australia during the next day or so, the trough will deepen southward west of the Queensland ranges, and into New South Wales west of the ranges, while the high will ridge along the coast, slowing the trough's eastward progression.
|9||.||Overview: The thermal
trough passed across today, with a return of rather wintery conditions to the southeast of
the country. Pressures rose quickly behind the trough from their lows of between 994 and
1001hPa during the past couple of days. A broad cold air field is moving through the Bight
and will continue to bring scattered showers particularly to Tasmania and the southern
parts of Victoria and South Australia. A weak trough extends from New South Wales to the
Northern Territory, while the high ridges through southern Western Australia. A cold front
is entering the western Bight. Moisture from the area of disorganised convection over the
Solomon Islands has drifted southwest to Cape York. A trough lies across the southern Top
Discussion: During Wednesday, the high will bud off into the Bight and strengthen, influencing much of the weather across the country with the exception of coastal Queensland, mainly in the south where scattered showers and isolated storms are likely as the trough moves into a moister environment, and Tasmania, still likely to be affected by showers courtesy of a moist westerly from the Bight. The west coast trough will begin to deepen just inland during Wednesday, and heating across the northwest of the continent will continue its seasonal increase.
|8||.||Overview: A complex
trough is moving over Victoria during Monday afternoon and evening after the initial
trough (which passed through during Sunday) began retrograding (drifting southwest)
towards the approaching stronger trough, with pressures dropping fairly consistently
across the southeast of the continent between central Victoria and central South Australia
during the day. A trough extends from southeastern New South Wales (another part of the
complex system over the southeast) to the Northern Territory. A deep low of 964hPa is
located within a broad upper trough over the southern Bight bringing very cold air towards
the southern coastline. The high to the west is ridging into southern Western Australia.
An area of strong convection is located over the Solomon Islands with moisture drifting
southwest towards Queensland.
Discussion: The northern part of the trough will move through New South Wales and Queensland during Tuesday, while over southeastern Australia, cooler conditions with widespread showers and isolated storms are likely. The high ridging across southern Western Australia will help direct a moist southwesterly flow onto the southern part of the continent. Strong winds over Tasmania will be associated with the passage of the low to the southwest. The high over New Zealand will ridge more weakly along the Queensland coast as it continues to move slowly east.
|7||Nick Sykes||Things are starting to look interesting for next weekend over SE Australia. GASP and AVN/MRF have a low pressure trough deepening to the west of Victoria over SA, in association with an approaching cold pool, what is really interesting is what the models have happening next. A high is forecasted to be blocked in the Tasman as the result of a low pressure sytem developing over NZ. This block will bring the movement of this trough to a crawl, and result in a very nice infeed of moisture from the NNE (Coral Sea). This type of setup can breed storms. NGP and EC push a weakening front a lot earlier, with no block, giving a boring change. Still a long way out but there to ponder.|
|7||.||Overview: A deepening
low is moving southeast through the Bight, followed by a satellite low moving northeast
towards the southwest coast which has brought a large cold air field over southern Western
Australia. A trough and front extends across western Victoria and South Australia during
Sunday evening. The high to the west of this sytem is ridging weakly to the northeast and
south. A weak tropical disturbance remains near the Solomon Islands. The high to the east
of Australia has moved slowly to be over the South Island of New Zealand.
Discussion: The low looks likely to continue it's southeast movement during Monday, deepening within a deepening upper trough over the Bight and bringing strengthening winds as far east as western Tasmania. The trough will move through New South Wales and Victoria by later Monday bringing mostly mid-level showers and scattered storms mostly ahead of the trailing front. The high over New Zealand will maintain the ridge along the Queensland coast. The high to the west will ridge into Western Australia near to or just south of 30°S.
|6||.||Overview: A complex low
over Victoria continues to move only slowly in a generally easterly direction. The
trough extending through northeastern New South Wales is storm active during Saturday
night. The high in the southern Tasman still extends a weak ridge under the trough
cradling it as well as helping to slow its eastward movement. A trough ahead of a
deepening low located south of Perth is drawing in a substantial amount of moisture from
the Indian Ocean. Moisture is building up over the northern parts of Queensland courtesy
of the broad convective area north east of the Coral Sea.
Discussion: The low near Perth will move southeast during Sunday and deepen, with the trough and front moving quickly east into South Australia during Sunday. This low is associated with a deepening upper trough over the southwestern Bight and will bring an extensive area of cold air across southern parts of Western Australia behind the front. The high to the west of the continent will move steadily east, but will not strengthen much over the next 24 hours. The high near to New Zealand will continue to ridge along the Queensland coast and will slow the movement of the trough. Moist infeed from the broad area of convection northeast of the Coral Sea is likely to continue at least through Sunday.
|5||.||Overview: A complex low
(analysed at all levels) has been located over Victoria during Friday with a trough
extending north to the tropics. Widespread storms over Victoria have been a feature of
this system as the low has moved further into the state. The weak high in the Bight
extended a ridge to the south of this system and into the Tasman, helping cradle the
system, while the high in the Tasman prevented any rapid eastward movement. The west coast
trough continued draw moisture in from the Indian Ocean and to deepen, while a low
pressure system and cold front, associated with a deepening upper trough is approaching
Western Australia. Tropical moisture continues to trickle steadily into the northeast of
Discussion: The weakening trough will drift generally southwards during Saturday, with the high in the Tasman strengthening as it also pushes south. In the north, this trough will begin to move eastwards, with scattered showers and isolated storms likely on its east side.The low will affect the southern parts of Western Australia with the west coast trough also moving east through the state together with this system. A very strong east-west temperature gradient will be a feature of this trough - front.
|4||.||Overview: The trough has
become quasi-stationary with cyclogenesis in the mid and upper levels translating
downwards towards the surface during the latter part of the day over southeast South
Australia. A trough also extends through the southern Tasman Sea. The high in the
Tasman ridges along the Queensland coast, while the high in the western Bight ridges to
the southeast below the trough, cutting it off from the westerly flow.
Discussion: The high in the Tasman will remain slow moving with the ridge continuing to lie along the Queensland coast. This surface high, supported by upper ridging above, will help to slow the eastward movement of the trough and developing low. The high in the Bight will ridge south of the trough and cradle it over the southeast through Friday. The west coast trough will deepen through Friday but remain about the coast, while the next frontal system is approaching Western Australia later Friday or Saturday. Northern Australia will remain under a rather generalised area of low pressure.
Areas to watch: keep an eye on the patch of cloud over the western Bight near to 40°S Thursday night and moving east.
|3||.||Overview: The high
remains over the northern Tasman Sea near to 30°S extending a ridge along the Queensland
coast. Northern Australia remains under a broad but mainly inactive trough. A complex
trough extends through South Australia, left behind when the front to the south sheared
away to the east. The high in the Tasman is blocking the eastward movement of this system.
The high to the west is ridging through the western Bight with ridges affecting northern
South Australia and to the southeast of the trough. The broad westerly flow has been
Discussion: All systems will remain slow moving if not quasi-stationary across eastern Australia during Thursday, with the high in the Tasman blocking the eastward movement of the trough. The tilting of the trough indicates the likelihood of cyclogenesis - most likely to be over the southeast South Australia / western Victoria area during the next 12 - 18 hours. The high ridging through the western Bight will remain south of the continent and may ridge south of the trough, further cradling it over the southeast of the continent. The west coast trough will begin to deepen just off the coast, bringing warmer conditions ahead of it.
|2||David Jones||Further to my post earlier in the week,
the progs are showing a convergence towards a significant trough/low developing through
central Vic in the coming two days (eg NOGAPS at http://188.8.131.52/CGI/PUBLIC/wxmap_all.cgi?type=prod&area=ngp_ausnz&prod=
prp ) This type of system is the "almost-classic" heavy rain producer for central Victoria. This is certainly one to watch. I wouldn't be surprised to see 25-50mm falls in the topographically favored central areas IF this eventuates. Also... watch for a strong front early next week...
|2||.||Overview: The high over
New South Wales has moved steadily east through Tuesday to be located just off the coast.
A weak ridge extends along the Queensland coast. Ahead of the approaching frontal system
and trough in the Bight, most of eastern Australia was fine after a cool night with
scattered inland frosts and fog patches. The trough over Western Australia is moving
through the east of the state, triggering storms along its length. Moist infeed from the
Indian Ocean into this trough (which is full height) continued through Tuesday.
Discussion: The high will move slowly away form the coast remaining near to 30°S during Wednesday, strengthening the ridge along the Queensland coast and directing a moist southeasterly flow over the southern New South Wales coast. Northwesterly winds with increasing temperatures ahead of, and showers and scattered storms with the deepening trough will affect southeastern Australia through midweek. It is likely that the southern part of the front will shear away and leave a lingering trough over the southeast of the continent during the latter part of the week. West of this system, the next high will ridge into the western Bight, with the trough over the west retracting northward.
|1||.||Overview: The high in
the Bight has continued to linger during Monday, only just making it to the southeast
coast of South Australia and remaining near to 35°S. The trough down the west coast has
deepened through Monday with an increase in tropical moisture feed from the Indian Ocean
into the area. A cold pool associated with the trough moving along the New South Wales
coast has triggered showers in its vicinity. The trough which lagged over the north of the
continent during last week has moved off the Queensland oast. A series of cold front is
just to the southwest of Western Australia but are unlikely to affect the southwest coast
while the ridge of high pressure steers them through the western Bight.
Discussion: The high will move into eastern Australia during Tuesday, steered northeast by a trough strengthening to the west. Cold nights and mainly fine conditions with frost and fog patches are likely. This high will also direct a moist onshore flow onto the Queensland coast. The west coast trough will move inland eastward from the coast during Tuesday, triggering showers and storms. Strong east-west temperature gradients are once again becoming more common across frontal boundaries as the continent heats up. The high in the Indian Ocean will ridge into our longitudes just to the south of the continent.
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