This was posted on John's Weather Channel on FB two days ago.
Look out for the cut off low referred to in the NSW report, which looks like developing around Thursday or so next week.
I'll be monitoring this one as it develops. As all the systems are pretty damp, big falls may lead to some moderate to major flooding.
Stay safe if you are out and about.
Regards
Doc.
*** PLEASE READ AND SHARE/TAG THIS IMPORTANT INFORMATION ****
**** EXCLUSIVE WRITE UP OF NASTY WEATHER TO COME OVER THE NEXT WEEK OR TWO STATE BY STATE ****
**** THIS COULD LIKELY BE THE MOST ACTIVE 10 DAYS OF THE YEAR FOR MOST OF AUSTRALIA ****
**** RAIN (POSSIBLE FLOODING IN PARTS) THUNDERSTORMS, VERY STRONG WINDS, HEAVY SNOWFALLS AT SKI RESORTS AUGUST 16TH TO AUGUST 26TH. ****
- Most of the country will see some of this weather the next 10 days.
- All states will be impacted
- Spring like temps expected across southern and eastern Australia ahead of these strong weather systems.
**** WESTERN AUSTRALIA ****
The two strongest fronts will come through tomorrow Wednesday August 17th and Monday August 22nd. Both systems are likely to deliver substantial rainfall for south west WA & Perth, thunderstorms and small hail. Winds will also be strong enough to cause damage.
Rainfall will accumulate with 30-60mm likely for south west WA especially regions from Perth down the coast through to Albany and as far east of Esperance, local falls as high as 80mm may add up between Bunbury and Albany for the two systems.
**** SOUTH AUSTRALIA ****
Patchy rain and showers will impact parts of the south east tonight but it won't be until later Thursday and Friday before a strong front will bring a band of rain and isolated thunderstorms, strong winds possibly damaging wind gusts also be associated with this front.
Colder temps & showers will continue about Agricultural regions especially southern parts through the weekend. Isolated thunderstorms also likely.
A new system next week and possibly the strongest and largest impact of the sequence will move from WA towards SA, the system will be a large cut off low with tropical moisture infeed from northern Australia. This system is likely to deliver rain and thunderstorms across most of the state with the heaviest falls at this stage expected about eastern and southern parts.
Agricultural regions will see good falls the next 10 days with widespread 10 to 30mm across the state 30-50mm about Southern Agricultural regions. Locally heavier falls in thunderstorms.
Adelaide is likely to see 25 to 50mm during this period. Locally heavier falls are possible.
**** TASMANIA ****
It is going to get wet and wild, flooding along some rivers may become a concern.
Rain will impact all of the state tonight/overnight and into tomorrow morning, isolated thunderstorms also possible. Good falls expected about the west and north west. The system will push into the Tasman sea later tomorrow taking most of the weather with it.
A more powerful system will push through early Friday with a substantial rainband, winds will also be strong possibly damaging gusts ahead and with the front. More rain already on wet catchments will impact the whole state but the heaviest falls will be about the west and northern parts. It will continue to be showery through the weekend and Monday in unstable westerly wind set up as further troughs move through the state. Isolated thunderstorms also likely.
Most of the state will see 15mm+ between tonight and Monday August 22nd but the west and north will see heavy falls accumulate, some parts will see 30-70mm with isolated totals of 100mm about western elevated parts.
It will become much colder with snowfalls down to 600-800 metres by Friday night and through the weekend and Monday.
Conditions will mostly clear Tuesday however further rain is possible later next week depending on the development and movement of the cut off low over South Australia (More info to come).
**** VICTORIA ****
Patchy rain or scattered showers will impact the state tonight and Wednesday morning but mostly for southern and mountain regions and falls will be be light as a weakening cold front crosses the state.
Winds will turn northerly Thursday throughout and become very strong ahead of a much stronger system. The front will push into western Victoria Thursday night and Friday with a band of substantial rain, Isolated thunderstorms also likely, damaging winds also possible ahead of and with the front.
Further showery periods will continue Saturday-Monday in an unstable and moist westerly flow as further short wave troughs cross the state from the west. Isolated thunderstorms also possible mostly about the ranges. Most of the state should see between 10 and 40mm between Friday and Monday night, locally higher falls possible about the north east ranges (50mm+)
Good snowfalls expected across the Victorian resorts Friday night to Monday with snow generally falling to as low as 900-1000 metres. Most resorts should see 15 to 40cms.
Conditions will finally ease by Tuesday as a weak high ridge moves over the state but there are growing concerns of further rainfall mid to late next week as a big cut off low moves from WA through SA and into the south eastern states.
Flooding may become an issue Friday & weekend on a few of the river systems especially the north east however if further rain moves in mid next week there is a REAL risk of flooding becoming a major problem through large parts of the state especially eastern regions. We will do another update about this on Friday or Saturday).
**** NEW SOUTH WALES ****
NSW will stay generally dry and mild until Friday the only exception will be few showers and possible isolated thunderstorms about the southern ranges Wednesday.
A strong cold front will traverse the state Friday it will bring a band of rain most regions away from the far north west and far north east. Most regions will see useful falls but the best of the falls will be about the southern and central tablelands and western slopes where 15 to 30mm is expected in these regions.
Winds will also become strong early Friday morning across southern parts with damaging winds possible about the southern highlands.
Showers will continue about the ranges especially central and southern ranges Saturday morning but will ease and generally clear central ranges by Saturday night however showers will continue about southern highlands which will tend to snow Friday night/Saturday morning 1000 metres, the Snowy mountains may see 15 to 30cms during this period.
In the north of the state a deepening trough on Monday may produce instability with showers and thunderstorms about the north east corner.
Good chance of further rain mid next week as a large cut off low and broad trough sweeps across the state from the west. There is the high chance of heavy falls about the ranges if this occurs. (More info to come Friday or Saturday).
**** QUEENSLAND ****
QLD Should remain generally stable apart from a few showers about the coast mostly central and north coast and isolated showers and possible thunder about far southern inland regions Friday afternoon and Saturday morning across the south east.
A developing trough Monday across the south east may produce some instability and parts of the south east may see some scattered showers and thunderstorm activity including the Brisbane and Gold coast regions.
Looking deeper into next week it is looking likely most of the state will see a major rain event thanks to a developing low over south eastern Australia, thunderstorms also likely. There are signs this rain will deliver heavy falls over parts of the central and southern inland with widespread 20 to 60mm across most of the state away from the far north west and far west, isolated totals of 100mm is possible about central and southern inland. Strong winds also possible with this system. (More info to come in the coming days).
**** NORTHERN TERRITORY ****
NT will generally stay fine most regions until early-mid next week when showers and storms may form across central/southern and eastern parts of the state, squally winds also associated with storms as a very strong upper trough and surface trough pushes across the state, a deep low will form south of the state. Conditions will become a lot cooler behind this system in southern regions.
Image one: The strong cold front expected to come through Perth and southern WA tomorrow Wednesday August 17th. Rainfall show by the EC model for Wednesday morning.
Image two: The same cold front moving through south eastern Australia which should deliver good falls parts of SE SA, VIC, TAS and parts of NSW for Friday August 19th. Rainfall shown by the EC model for Friday.
Image three to six: Four models showing the prospects of a significant low pressure cut off system next week Tuesday to Friday period (Aug 23rd to Aug 26th). From left to right.. CFS model mid week, CFS model late week, EC/Euro model and ACCESS models. GFS model also shows a very similar scenario to these three models. These images are provided by Piovtal Weather.
The development and movement of this system will determine which areas will get significant rainfall but most of eastern and southern Australia should see some rainfall out of this, some parts it is likely to be heavy enough to cause flooding.
- JWC
John's Weather Channel - JWC's photo.
John's Weather Channel - JWC's photo.
John's Weather Channel - JWC's photo.