The Weather Man

National: Wet 48 hours in the SE States.

A surface low supported by an upper disturbance and several associated troughs will maintain showers and thunderstorms and areas of rain about the south east mainland states in the next 48 hours with showers and thunderstorms extending into Queensland and Northern Territory.

The potential of localised heavy falls exists through parts of South Australia, New South Wales, ACT and Victoria although the more widespread heavier totals will be associated with thundery rain with areas experiencing more localised showers and thunderstorms expected to record patchier heavier falls. 

Weather warnings have already been issued including a Flood Watch in South Australia and Severe Thunderstorm Warnings and further weather warnings are likely in the coming 2 days. You can see what warning impact your state and region here. http://www.bom.gov.au/australia/warnings/index.shtml

By the weekend a high will ridge through the south east states with a clearing pattern although onshore winds will maintain potential showers about the New South Wales coast.

National: October mostly hot and dry but more November rainfall ahead.

Nationally October heat records were broken with many of the individual states also setting new October temperatures records with Canberra, Melbourne, Perth and Adelaide also setting new October heat. See how your state and city or town fared.  http://www.bom.gov.au/climate/current/statement_archives.shtml

There is more rain ahead across the mainland southern states and New South Wales/ACT as a deepening surface trough and associated low combine with an upper level disturbance and moisture feeding into and ahead of the surface trough. Thunderstorm activity is expected to produce the heavier of the falls and there should be a fairly extensive band of thundery rain develop about the south east quarter of New South Wales and into the north east of Victoria. 

As with the weekends system the forecast models are suggesting widespread heavy falls but as much of the higher rainfall will be associated with thunderstorms the heavier falls are more likely in the identified regions more than widespread falls to those levels in those regions. there is also the potential for severe thunderstorms developing through the week so keep an eye on your states weather warnings. http://www.bom.gov.au/australia/warnings/index.shtml

Showers and thunderstorms will also extend from the north west of the Northern Territory and into the western and southern inland of Queensland but at this stage the falls will be patchier and lighter than the more southern states.

National: Heavy rain expected for parts of the east this weekend.

A slow moving trough extends from east of Adelaide to Mt Isa and back into the Northern Territory and will deepen over the weekend as an upper level cold pool approaches in from the west. At the same time a high in the Tasman Sea is directing a warm and moist airflow into Queensland east of the trough and down into the South East States. These three elements will combine to trigger increasing showers and thunderstorms across parts of Victoria New South Wales and Queensland with some possible localised heavy falls with NSW and parts of the ACT expected to record the more widespread heavier falls with widespread totals in the 30 to 60mm range over the weekend.

Parts of Victoria and southern New South Wales are expected to record quite heavy falls especially on Sunday with warnings for heavy rainfall already issued in Victoria

A second system is expected to form in Western Australia on Sunday and deepen on Monday as it moves east with another burst of possible heavy falls although at this stage there is still some variation in the positioning of the low and resulting rainfall so it will still be another day or two before the location and amounts of rainfall will be clearer.

National: Promising rainfalls till Tuesday then models differ.

A series of troughs and upper disturbances will maintain a very unstable atmosphere in the coming days and combine with moisture feeding in from the Coral Sea and Indian Ocean to produce the potential for widespread showers and thunderstorms with the better of the falls above about 5 to 10mm mostly confined to the ranges and slopes of NSW, western ACT, north east ranges of Victoria and the southern and central inland of Queensland. Most of this activity will be shower and thunderstorm based so whilst there may be some heavy falls the general rainfall potential will sit around the 10 to 15mm range with more isolated heavier falls directly under thunderstorms.

Another trough and associated low is expected to form in Western Australia on Monday but forecast models are showing quite large variations in the movement and impact of this system in the central and eastern states so any rainfall outcome is quite uncertain at this stage. 

National: Thunderstorms becoming more widespread by the weekend.

A belt of high pressure sitting south of the continent is allowing hot air to develop over much of the inland and this is allowing troughs to develop and remain slow moving sparking areas of active thunderstorms. By the weekend one of these troughs interacts with an upper level cold pool and deepens as it moves east. At the same time a high has ridged up the east coast and the resulting onshore winds is drawing humid air into the eastern inland.

As the trough and this moisture combine with afternoon heating and instability on Saturday thunderstorms will develop across the eastern inland and central parts of the continent and the slow moving nature of the thunderstorms could lead to localised heavy rainfall although there is still considerable variation between forecast models as to the amount of possible rainfall.

The storms will move further east on Monday as the next high begins to ridge through the south east and up the New South Wales coast with another trough developing across central Australia. although thunderstorms are expected to produce widespread falls it will still be hit and miss in some areas so while parts may record decent totals others may miss out and overall rainfall totals in the chart below are an impression of falls with the showers and thunderstorms rather than the expectation for widespread rainfall of those amounts.

 

National: Humid and unsettled weekend for the east

As a high moves into the Tasman sea over the coming four days a moist onshore wind flow develops along the Queensland coast and moisture associated with this will move inland and south reaching New South Wales, ACT, Victoria and Tasmania. In combination with an east moving trough the potential for thundery showers redevelops in these states through the weekend. At this stage there is still some variation between models with respect to how much rain will fall but going by recent events there is a quite good potential for some locally heavy falls with thunderstorms although the more widespread expectations are for more general lighter falls with the more western areas of Queensland, New South Wales and Victoria more likely to miss out.

During next week models suggest a surface and upper low developing over Western Australia with moisture feeding in from the Indian Ocean, this system is worth watching for another burst of falls across the south of Western Australia and eastern states but it is far too early to be confident on location and amounts of rainfall.

National: Hit and miss as rainfall remains patchy

At the moment and in recent weeks, rainfall patterns across the continent have been centred around troughs and upper level disturbances triggering shower and thunderstorms. This pattern of convective cloud is resulting in rainfall that tends to be hit and miss unless there is a substantial amount of moisture and the right atmospheric conditions to produce more widespread rainfall or widespread heavier falls from storms. Those sort of atmospheric conditions are missing at the moment and my not be a regular feature in the coming months under the current El Nino climate pattern. 

As a result although we see and hear of thunderstorms across Eastern Australia the amount of worthwhile rainfall is often only falling in parts of weather districts whilst nearby locations only record light falls or in some cases nothing at all.

Forecast models beyond 4 days are suggesting plenty of rainfall but the sad reality is most of that is likely to be patchy and associated with thunderstorms rather than widespread and evenly dispersed rainfall. If recent weeks are anything to go by an over exuberant forecast for rainfall often pares back within the 4 day window so anything beyond that window should be viewed with caution.

National: More thundery showers for the east

Recent thunderstorms have made inroads into October rainfall deficiencies but much more is needed and although the forecast for rainfall next week in the eastern states looks promising it will be a hit and miss affair as it is associated with showers and thunderstorms.

This means that whilst some locations could see some localised heavy falls areas not that far away will only record very light and potentially no rain. The bonus with the coming week is that the unsettled conditions will last a number of days which will offer an opportunity for more widespread falls than if it was only a day or two of activity.

Many of the severely drought affected areas will remain dry or record only patchy light falls with eastern Victoria, eastern New South Wales, ACT and the southern Inland of Queensland looking most likely to record some decent rainfall.

The record to near record October average maximum temperature in much of New South Wales, ACT, Victoria, Tasmania, South Australia and parts of southern Western Australia look like continuing with forecast models indicating no influx of substantially below average temperatures during the remainder of the month as high pressure systems will remain mostly centred south of the continent keeping strong cold fronts and colder air at bay.

National: Widespread thundery showers for the SE but how much rain a little uncertain

Forecast models are very good at picking rainfall including the amounts and locations although there are often occasions where they do not pick up the isolated heavier falls which can occur due to local effects. This seems to be the current situation especially in relation to thunderstorms associated with troughs where there have been some localised heavy falls well above the forecast rainfall amounts. 

During today and tomorrow this is likely to be the case with the majority of the south east states expecting falls mostly below 10mm with most more likely to record less than 5, but within this are localised storms could trigger heavier falls. There is also the potential for severe thunderstorms with possible damaging winds and large hail and perhaps localised heavy falls.

Another interesting feature on Wednesday will be an area of rain, as a low forms along a trough, spreading over North East Victoria, East Gippsland and the far South East of New South Wales where more widespread falls in the 15 to 30mm range could be quite widespread. Models have been suggesting this since late last week but eased back on the rainfall amounts through the weekend but have increased the totals in the last two runs.

If you are in New South Wales, ACT or Queensland and miss out on worthwhile rainfall over the next 2 days another trough looks to be thunderstorm active next week with forecast models again picking some locally heavier falls so this will be worth watching.

National: Cloud heading for the east but falls do not look impressive.

A weak trough and front are moving east and although cloud has increased through South Australia today the amount of rainfall expected from this system is quite poor with many areas of the south east states expected to record falls below 5mm. There is the potential for some thunderstorms which may produce some localised heavier falls but these will be patchy and very hit and miss.

As the system reaches the NE and Gippsland ranges of Victoria and ranges south of about Albury, Cooma to Bermagui in New South Wales there could be some more widespread totals in the 10 to 20mm range but these may also be quite patchy. the system clears the east coast on Thursday with another burst of well above average temperatures over the weekend.