SATURDAY MORNING WEATHER - RAIN CONTINUES WITH HEAVY FALLS OVER THE EAST WITH WARMER WEATHER WEST.

OVERVIEW

Rain continues to contract eastwards with the trough over QLD starting to move onto the east coast with the heavy rainfall expected to continue with below average temperatures and above average rainfall the theme of the weekend.


Rain has continued to tumble over inland NSW and through areas of the ACT with some reasonable falls under the upper low, but the rainfall distribution has not been even with variation in the rainfall distribution expected to continue.


Along the east coast, the rainfall is forecast to increase further today, with some areas recording over 50mm along areas of the NSW Coast and this will be a feature throughout the weekend.


Rainfall along the QLD coast will increase again on Sunday afternoon before spreading south with heavy falls during Monday and into Tuesday with a low-pressure system forecast to develop along the trough, there may be one offshore QLD and another offshore NSW, both bringing torrential falls but pinning that down will be like pin the low-pressure system on the synoptic chart. Watch the forecasts closely if you are living on the east coast.


SHORT TERM

Elsewhere the rest of the nation is quiet, high pressure in control bringing settled weather through VIC, SA and into WA. The dry weather will resume over the NT with colder weather persisting with below average temperatures.


A weak cold front is forecast to move into the SWLD of WA on Monday bringing a burst of showers, but in the east a sharpening upper trough will continue to drive severe weather.


Once the east coast system begins to lift offshore and onto NZ, the frontal weather should be moving through the SWLD of WA with rainfall becoming more frequent with the chance of moderate falls developing for the Agricultural areas of the west. While the rainfall will be welcome it may not be enough to overcome the below average spell of rainfall we have been seeing in recent weeks.


Rainfall will then spread into southern and southeastern parts of the nation, the falls here too mainly light to moderate and likely not enough to overcome this current dry spell and make up for the deficits.


The northern and eastern areas of the nation should return to seasonal weather with the westerly wind regime unfolding in response to the SAM trending more neutral.


LONG TERM

The frontal weather will be of interest for southern Australia with a fair few to pass through the nation’s southwest and southeast with the axis of the long wave trough possibly too far south to bring larger rainfall expectations for SA at this time, but light falls yes, looking more likely.


Moisture over the Indian Ocean could be drawn into the frontal boundaries west of WA and this may see rainfall increasing from next weekend and into the second week of July with strong and gusty winds and colder air filtering through after a milder week.


Dry season weather should resume over northern and northeastern parts of the country following the substantial rain event, but the sea surface temperatures are likely to stay elevated, lifting the chance of follow up rainfall in these areas into July and August.


AREAS TO WATCH

The Indian Ocean Dipole is developing, and it should begin to have some influence over the nation as we move through July.


The SAM is expected to turn more negative as we move into July, and this is supporting the frontal weather heading northwards through the Southern Ocean towards Australia.


FORECAST

Rainfall Next 10 Days

The rainfall continues to pound down over parts of QLD and NSW into the ACT with a series of troughs and deep moisture levels leading to widespread above average totals today. The rainfall is locally intense as well with the risk of high-end flash flooding and riverine flooding expanding along the coast and adjacent coastal ranges in NSW today and then developing through parts of Central QLD through the early part of next week. The weather in the east will ease by mid next week as the trough and deep moisture finally leaves and takes the low-pressure systems with it. Significant shower activity will develop over in the SWLD during Tuesday with a front passing through, but that system will dive away to the southeast. It won't be until we see a major weather system develop through the region in about a week from today that we see widespread rainfall return to the southwest and west of the nation, those fronts then running through the country's south bringing light falls to SA and a better chance of rainfall into VIC and TAS. Drier air will then resume for much of central and northern Australia with limited rainfall at this time. As we work through the middle of July, we will have more frequent rainfall spreading across southern Australia.


NEW SOUTH WALES AND VICTORIA

Widespread rainfall is ongoing about parts of the east today and intensifying further through the coming 2 days before easing. Inland NSW likely to see some scattered moderate rainfall with thunderstorms about today. Otherwise the rest of the southeast is dry with settled weather under high pressure. It takes until the end of Wednesday for the east coast to see some clearance of the severe weather and drier weather returns to the inland. Rainfall returns to southern Australia with the risk of light falls extending inland but the coverage of rainfall is forecast to be relatively patchy. The weather pattern should turn more seasonal as we go through the following weekend with the chance of further frontal weather bringing back rainfall to the southeast areas exposed to the westerly wind regime.


SOUTHERN AND CENTRAL QLD

Widespread showers and thunderstorms are forecast to impact eastern QLD from Mackay southwards through the coming 2 to 3 days with an upper trough likely to intensify and drift through combining with deep moisture to produce the widespread falls. The rainfall could lead to flooding. Rainfall contracting east through QLD with the trough slowly creeping towards the east. So rainfall ending from west to east through the weekend and into next week. Once we get the trough offshore the coast mid week, conditions should be mostly dry state wide.

NORTHERN AUSTRALIA

As mentioned above, drier weather resumes for much of the nation’s north once we get the trough and moisture out to the east and north and drier air surges in from the south through the week.

WESTERN AUSTRALIA

A weak system coming through the southwest on Tuesday may bring a brief burst of rainfall through the SWLD but the coverage of rainfall limited to the southwest coastal areas. Then stronger fronts line up the SWLD with moderate falls developing with these features next weekend and that should persist through the medium term with further frontal weather.

SOUTH AUSTRALIA

Rainfall limited to coastal areas with frontal weather developing next week as we track a series of cold fronts through the Bight and into the southeast inland of the country, the orientation of these not favouring large rainfall totals for the south of the country so the below average rainfall signature continues for the state for now, with the best of it falling over the southeast of the state towards VIC.

THUNDERSTORM FORECAST

Thunderstorm Forecast Saturday

A broad upper low and deepening moisture profile could see thunderstorms develop along the east coast and the adjacent inland but conditions clearing from the western interior of QLD. Heavy rainfall with isolated thunderstorms is possible about the coastal areas.

Thunderstorm Forecast Sunday

Thunderstorm risk forecast to contract to the coast with heavy rainfall leading to flash flooding the main issues for pockets of the QLD and NSW coastal areas.

Thunderstorm Forecast Monday

Thunderstorms along the coast of QLD and NSW with a deep trough and potential low-pressure system, could deliver heavy rainfall leading to flash and riverine flooding. Stable most elsewhere.

Thunderstorm Forecast Tuesday

Thunderstorms are still possible in the presence of an upper trough near the QLD coast from Mackay southwards and through the NSW border down to the Hunter. A low-pressure system offshore the NSW coast could also bring storms further south of Sydney as well but the confidence of that is quite poor.

Thunderstorm Forecast Wednesday

Nil Thunderstorms Expected

WEATHER ISSUES

FLASH FLOOD RISK - NSW

Flash flooding is a high risk at this stage, could easily lift it to very high chance over parts of the coast from Wollongong to Narooma with a trough on Friday night into Saturday and over the Northern Rivers and then extending up and down the coast this weekend into early next week. Severe flash flooding is possible over large population centres this weekend and into early next week along the Central and Southern Coast. A low risk at the moment under an upper low over the inland, particularly Central West during Saturday and Sunday with slow moving areas of rainfall, this may extend towards the Southern Tablelands and Southwest Slopes and ACT, placement of the upper low key. While it has been drier the past 2 weeks or so, be aware that it won't take much to get the runoff going again.

MEDIUM TERM

July 9th - July 16th, 2022

Rainfall Anomalies

Rainfall is expected to retreat back to seasonal expectations, with the numbers coming up over the southwest and southeast of the nation, with frontal weather moving through at regular intervals. Watching the impact of the SSTs offshore WA, if they can continue to warm through the weeks ahead, the frontal weather when present will bring heavier rainfall than advertised!

Temperature Anomalies

A strong cooler bias looks to continue into mid-month for large sections of the NT and QLD, perhaps picking up on the cloud spreading through the jet stream and the recovery from this very anomalous rain event which has cooled the interior in a major way. Could be the coolest spell for the NT in about 40 years. Otherwise, the consequences for the rest of the interior is cooler than normal weather for the middle of the month. Maybe a sign of what is to come into Spring.

DATA - No video today as I catch a little breath from the crazy week and I am covering off the severe weather event for some media outlets this morning, so look out for me there, but more updates throughout the day and into the afternoon with the severe weather in the east and a better look at the system over in WA next weekend. Those are the key interest points in terms of weather makers in the days ahead.


12Z GFS Surface Pressure Pattern and Rainfall Distribution - Next 16 Days

The unusual weather pattern driving the severe weather risks will begin to ease over the nation as we track in through the week, but stay close to the forecast packages as we go through the coming days. SEVERE WEATHER WARNINGS are out and likely to be issued further through the coming days. Drier weather will continue for the south and southwest of the country before we see frontal weather return into the week becoming more frequent later this week. Essentially, the coverage of rainfall and a pattern flip for the west and southwest of the nation will be determined by the block over the east, and how quick that moves off. That will the open the door to weather coming in from west to east, rather from north to south, which is something you see more in Spring rather than Winter. But a good indication of what is to come for many of you this Spring time in terms of what we have seen moisture and rainfall spread wise in the past few days and ongoing today. More on that this week.

12z GFS Precipitable Water Anomalies - Next 16 Days

Deep moisture is going to be slow to move onto the north and east but once it does, more seasonal weather should resume across the nation as we see a drier southerly flow push through Australia. Frontal weather will help to drag in moisture over the nation from the northwest through to the southeast with patchier falls expected over southern Australia from later next week however they may increase over the SWLD next weekend. More traditional values are forecast to emerge in the outlook away from that very deep and anomalous moisture, but take note, as this will be repeated time and time again through the coming 6 months.

12z Euro Rainfall Accumulation - Next 10 days

As per the guidance the rainfall over the east, it is becoming more coastal as we go through the coming 2 days with severe weather placed through the east of QLD Monday to Tuesday and along the NSW coast from today through Tuesday with the focus from Sydney to about Batemans Bay. Showers will resume over the southwest this week and gradually spread across the nation from west to east with the frontal weather starting to impact the nation more as we go through to mid July.

12z GFS Rainfall Accumulation - Next 16 days

You can see once we lose the intensive rainfall over the east and southeast of the country that there is really not a whole lot in the medium term that offer significant rainfall totals of note. Showers and windy weather will resume over southern Australia but not seeing that intrusion of moisture over the Indian Ocean getting drawn in just yet, but keep watching, these things evolve quite quickly.

More coming up throughout the day, will take a look at the severe weather potential throughout the remainder of today after the deluge overnight for some in NSW and QLD with moderate falls throughout the ACT.

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