MODELS AND RAINFALL - NOW WE CAN SEE THE SHIFT BACK INTO THE WESTERLY WIND REGIME.

The westerly wind regime is expected to emerge out of the Southern Ocean from the weekend starting to impact the SWLD of WA initially but then sweeping through the southern states and southeast next week with the development of strong cold fronts within the westerly wind belt. But it is the northern flank of these fronts that bring the rainfall and sadly, they are a little too far south for widespread significant heavy falls that are needed in SA and VIC but rainfall is on the way none the less.


The rainfall over in WA should be heavy this weekend about Ag Areas with the strongest cold fronts of the sequence. This is the system that moves into the southeast next week.


Follow up cold fronts may impact the southwest of the nation through next week and these glancing the southeast following the major front early in the period.


The east should begin to dry out with ridging, but there is a wild card in that moisture left over from this current event may also be lifted by the front coming through during Monday, but the confidence is not high on that event unfolding.


Overall, it is looking much more traditional rainfall wise for this time of year.


ENSEMBLE DATA


GFS - Rainfall Next 16 Days (median of 35 members) - MODERATE CHANCE

The latest GFS is drying out over the east of the nation with the focus of rainfall bearing systems starting to impact southern Australia more than the east of the nation. The rainfall is not expected to be anything exceeding the seasonal averages right now but the pattern is expected to flip in response to a more typical Winter pattern evolving. This model still supports the low chance of rainfall over the eastern interior with frontal weather next week.

CMC - Rainfall Next 15 Days (median of 30 members) - MODERATE CHANCE

The latest CMC also drying out the east after the next 24hrs of rainfall, with the frontal weather coming back and starting to impact the south of the country from the weekend, recaching the southwest first and the southeast early in the new week. Further frontal weather and westerly winds are also expected to feature throughout the medium term, but at this time, the modelling is not supportive of moisture being drawn in from the Indian Ocean. Note the grey shading appearing over the interior however, that is indicating something is lurking as we get towards the end of the period.

EURO - Rainfall Next 15 Days (median of 51 members) - MODERATE CHANCE

There is relatively good agreement across the models in rainfall placement and you can see from the Euro tonight that the Winter pattern should return with frontal weather driving the rainfall once the blocking easterly pattern resolves this weekend. A drier airmass looks to win out over the interior, but watch the interior closely as we could see moisture return via the jet stream thanks to the Indian Ocean and that moisture north of Australia could also approach for the end of the month too.



LONG TERM

CFS - Rainfall July 22nd-August 1st 2022 - MODERATE CHANCE

The CFS persists with the idea of moisture cutting through the nation from the Indian Ocean through this period and this is connected to the westerly wind belt standing further north and colliding with the moisture surging in via the jet stream. This may lead to a broad rain band cutting across the country and widespread rainfall moving further north over the southern states. So that is about 3 weeks away!

CFS - Rainfall Next 6 Weeks - MODERATE CHANCE

The outlook still very much persistent in the idea on moisture returning via the jet stream through late July and increasing through August with rainfall becoming more widespread as we go through the remainder of the season as outlined in the update this morning.

More coming up from 5am EST looking at the systems of interest and weather news you need to know.