WA - FINE AND DRY FOR MOST OF YOU INTO NEXT WEEK WITH FRONTAL WEATHER INCREASING FROM MONDAY.

OVERVIEW

The pattern is remaining benign and while it is quite frustrating for those who want rainfall, the pattern will eventually breakdown with the low-pressure system in the east moving off to NZ, this allowing the slow moving high to move out to SA and VIC and opening the door to frontal weather passing through the state.


So showers will return to the region from Monday and increase from Wednesday and later in the week as a long wave passes through from the Indian Ocean and over the state.


SHORT TERM

So as mentioned, as the frontal weather begins to move through from next week, the weather will turn more cloudy, with frequent bursts of rainfall, the first lot, not that heavy and restricted to coastal areas but as we move into the middle and latter part of the week, the rainfall coverage should increase further with moderate to possibly heavy falls developing with the fronts coming through.


Colder weather is expected to spread through the southwest inland with frontal weather starting to peak over the weekend and then that weather should move east, sending the wind bearing into the southwest.


This sequence will offer the next wave of risk to graziers as well, after what has been a mild and sunny spell.


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 be somewhat limited in the next 5 days as the high pressure system continues to sit over the region. Once the low pressure system out east moves away, the door will remain open to frontal weather. The first one, weak and only bringing showers to the southwest coastal areas and light and patchy falls inland. A second front approaching on Wednesday into Thursday may be stronger and contain a moisture in feed from the Indian Ocean leading to a better chance of rainfall moving through the SWLD. Some of that may drift through the Wheatbelt and Goldfields. A stronger front and probably the most promising comes through the weekend with a broader band of rainfall and troughs rotating around a cold and unstable southwesterly flow with further rainfall for the SWLD. Moderate to heavy rainfall with this front is possible. It may not be enough to make up for the dry spell however but will kick into gear a wetter spell with some luck and more traditional weather.

A broader view shows the extent of the dry air and the presence of high pressure throughout the region. It will break down and I will start drawing in more rainfall as the frontal weather build via the westerly winds during the outlook period.

Still a big bag of nothing generally for the northwest of the nation under high pressure.

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 - the driest part of the nation is the west for the week ahead with a lack of frontal weather and dry air combining to bring clear skies. Thanks to the block out east producing the highly anomalous weather, the rainfall won't return with substance until mid to late next weekend now, but the forecast confidence nationally is not especially high so keep watching.

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




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