NSW - SHOWERS MOVE INTO THE INLAND, RAIN INCREASING LATER THIS WEEK.

OVERVIEW

The rain is set to increase from tomorrow through QLD and the showery weather with the upper low over the southeast of the nation tonight will shift northwards with the upper low meeting that moisture through QLD, this leading to more widespread rainfall over the state.


The far west may miss out on the rainfall in the short term and sit in sinking air with a ridge nearby with seasonal temperatures. So, a dry spell is likely to continue for the west.


SHORT TERM

It is all about this upper level low and where it tracks. The upper level low is expected to fuel some active areas of rain and thunder for the northern and eastern parts of the country, and this coming into play for NSW Friday and then spreading south down the coast from the weekend with locally heavy rainfall possible. Over the inland, there is likely to be scattered showers under the upper low, which may increase this weekend with moderate falls possible mainly closer to the ranges.


Depending on the placement of the upper low, this will impact the placement of the trough along the coast with that then impacting the rainfall spread. So expect further changes through the coming 24 hours for the weekend rainfall. Some areas could see up to 200mm through the weekend, leading to the severe weather risk being widespread along the coast. But the risk will become more defined as we go through the next day or two.


Rain will clear the east coast early next week with the trough lifting away and the low diving southeast.


Westerly winds are forecast to return to the forecast next week for southern Australia and how the severe weather event in the ease resolves will then impact the passage of frontal weather over the state from later next week, that looks to be the next major change moving through.


LONG TERM

The frontal weather should resume over Southern Australia from next week, with the heavier impacts being felt over SWLD of WA through the back half of next week, with moderate rainfall possible with that feature, bringing an end to the dry spell for most areas.


The rainfall is expected to be widespread across the west of the nation until we see that spread further east to impact southern areas of SA and then into the southeast inland across VIC and maybe southern NSW. Moisture dependent, the rain bands may increase in coverage in future modelling so will be watching the Indian Ocean closely.


Otherwise the rest of the north and east of the nation is expected to clear with drier air surging northwards with high pressure coming in from the west.


AREAS TO WATCH

The focus of the weather shifts to the west of the nation next week, how much moisture can be drawn into the jet stream and will this bring back the wet weather back into the southern and southeastern parts of the nation breaking the drier spell of the recent week or two.


WEATHER VIDEO PM - WEDNESDAY 29TH JUNE 2022

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to remain very much confined to the east coast with heaviest coverage but will extend inland with light to moderate totals through to about plains before the rainfall tends non existent in the far west. The rainfall under the upper low could be somewhat uneven in distribution with some areas seeing 20-30mm and other areas only up to 5mm so be aware of that if you are living west of the divide. The east coast is forecast to be very damp, with pockets recording up to 200mm and widespread falls up to 50mm for many of you there. The wet weather will ease over the course of early next week as the low and trough moves away. Fine weather for the most part into early next week with the next wave of fronts on the board for the west and southwest of the country with wet weather returning to the southeast of the country from later next week with mainly light falls on and west of the divide. Noting that the rainfall has picked up a bit over the inland for the short term but there is further rainfall coming in later next week as well. The rainfall is still expected to shift over the inland as the models recognise the influence of the upper low.

Area of concern will be the coast between Newcastle and Merimbula at the moment with heavy convergent rainfall possible from Friday night through Monday and this is in connection to an east coast low forming, but understand that this will move around. Also noting the rainfall over the inland is increasing, but the coverage will be uneven so keep watch, upper lows are notorious for being very hard to pin down!

SEVERE WEATHER WATCH - NSW

An upper low that is forming over SA today is forecast to move into the NSW on Thursday and remain slow moving over the interior from Friday and into the weekend, leading to showers over the inland. But the upper low will help to draw in deep moisture from the north and east with a trough forming along the coast. It will be this trough that increases the risk of severe weather over parts of the NSW coast from Friday and then persisting through the weekend with the risk of high impact flash flooding with the slow-moving areas of heavy rainfall near the coast and then damaging winds developing in the presence of a surface low during the latter part of the weekend and into early next week. Also watching the heavy rainfall threat spilling south from QLD into northeast NSW later in the weekend and heavy rainfall in pockets under the upper low over the inland.

RIVERINE FLOOD RISK - NSW

A moderate to high risk of riverine flooding developing once again along the coast from Narooma northwards with a few pockets where the risk is higher in relation to the topography and shape of the coast and how the trough/low pressure behaves and sets up. Understand that this forecast is a heads up and the risk zones will become more refined as we move forward through the days ahead, but we could see conditions supportive of flooding emerge from Friday night onwards through the weekend and into early next week.

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. 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 7th - July 14th, 2022

Rainfall Anomalies

The lingering wetter signal over the east is weakening in strength but it is still there, and generally seasonal conditions are expected elsewhere at this time for the 2nd week of July. The rainfall over the southern coastal areas will become clearer as we get a better read on the strength and phase of the SAM.

Temperature Anomalies

Below average temperatures are likely to continue over parts of the north of the nation in response to the prolonged period of inland and dry season rainfall and cloud so that could see many areas stay below 30C for a while. Cooler through parts of southern Australia and out west with the warmer bias easing over northeast areas of NSW and southern QLD.

DATA - Refer to the video for further context and support for the short and medium term.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

Refer to the video for further context. There is a lot of complexity and that is causing a lot of shifting around in the rainfall totals from run to run in the east. Find out more about what you may expect in the video at the top of the page. The overall trend for the west is quiet before the pattern flips next week.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Moisture is largely unchanged from overnight and this morning, the deep moisture profile over the north and east will be full realised beyond the thick high cloud that has been covering large areas of the nation today, with a middle and lower-level deck of cloud likely to develop from tomorrow as a stronger forcing mechanism in the upper low meets the moisture, and then the ingredients combine to produce heavy rainfall potential for the east. The moisture will take a while to sweep out to the east but once it does, we will see the moisture return over western areas of the nation, chiefly in the south with frontal weather helping to bring back rainfall and more typical weather for this time of year after a dry spell. That moisture will reach the south and southeast later next week into the following weekend with follow up fronts to come over the south and west.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - widespread rainfall is expected to form along the coast with torrential falls. The heavier rainfall will move around from run to run depending on what model you are using and this will be the case until tomorrow night. Stay close to the forecasts and advice moving forward. The rainfall eases next week over NSW but returns to the south and southeast from later next week into the weekend with frontal weather returning.

More coming up from 8pm EST with a look at the models and rainfall and there is lots to discuss.




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