Mullaley Weekly Forecast

Weekly Updated Forecast, issued June 19th.

Weather Situation :

Further weak fronts are moving across Southern Australia, and will maintain showers in Southern parts of the country, with a small upper low to bring showers into Western and Southern SA tonight. These showers will push inland and ease tomorrow, before clearing. Later this week, a significant push of moisture will develop in Western Australia, and this will push rain into Southern and Central WA, at this stage widespread rain is likely to spread into much of the cropping region, and will be a carbon copy of last weeks event there. This system will be pushing East, but will die out as it moves into SA, as a trough in Eastern Australia will create a blocking mechanism. We will also see showers in NSW and QLD start to develop as the atmosphere becomes a bit more unstable, with low level moisture pushing in from the East. 

Week 1,      June 19th – June 26th.

Coastal showers will generally continue in NSW this week.

It will be unstable generally, some showers are possible inland this weekend.

Another system will develop along coastal areas over the weekend.

Showers will again develop and spread right down coastal districts to the South coast.

Rainfall :  0 – 1 mm

Forecast Confidence :  Medium

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Week 2,      June 27th – July 3rd.

It will start to become more unstable in week 2, as moisture increases.

Rain will push across from there West and slowly build into NSW

A big rain event will develop later in week 2 inland, and then move South East

It is too early to tell on how big this system will be, will update again in a few days.

Rainfall : 5 – 10 mm

Forecast Confidence :   Medium 

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Week 3,     July 4th – July 11th.

The trade wind burst will now start moving moisture West.

The MJO will be in Phase 4, and heavy rain is likely from the North across Eastern Australia.

That means we may see WA return to dry weather again as higher pressure moves in.

The tropical Convergence Zone will now be located directly North of Australia.

Rainfall :  15 – 30 mm

Forecast Confidence : Medium

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Week 4,     July 12th – July 19th.

From here on, the Indian Ocean will start to become dominant.

Lower pressure should start to set up in the Indian Ocean.

Western Australia should begin to see rain increase briefly as lots of cloud bands push across.

The AAO will turn positive, allowing lots of tropical cloud bands to push across the country.

Rainfall :  10 – 20 mm

Forecast Confidence :  Medium.

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Notes : The climate system is now shifting, warm waters in the Indian Ocean mean we are going to see a big increase in rainfall.  The forecasts are obviously targeting the first two weeks, with week 3 and 4 having much less accuracy. The general trend is for rain to drastically start increasing from here on, with upper troughs also now very active. This will mean much wetter conditions, and cooler temps as well, especially in Southern areas. Atmospheric Rivers are again developing through QLD and Northern WA, and also through the Bight. This means that lower pressure will develop rather than higher pressure zones, and that should maintain an active period this winter, with a good chance of above average rainfall for Southern areas. At this stage, a neutral IOD and a weak La Nina are likely to begin developing late in winter.