NORTHWEST CLOUD BANDS TO COME?

The modelling is quite atrocious at the moment, and I have mentioned that I am looking at trends overall.


The overwhelming trend from the modelling has been in the rainfall distribution shifting from the warmer season (easterly bias) to the cooler season (westerly bias).


As we get more westerly wind dominance across the nation in the next few months, the warmer waters of the Indian Ocean will come into play, the Indian Ocean Dipole is set to develop through June, increase through July to September and peak in October and November then rapidly wane.


The impacts are more cloud bands across the nation leading to widespread inland rainfall and potential for more severe weather across the country through what is traditionally the driest time of year in Australia as a whole.


MODELS AND THE CLOUD BAND POTENTIAL SHORT TERM

I think this reflects the region of potential impact based off the divergence in the modelling and the timing of cloud bands moving through over the coming week. And there is further cloud bands into the medium term too which also will be looked at in the coming week. But certainly the first event on the board that spreads through the nation could kick off from next Thursday or Friday and then into the first few days of June.

RAINFALL

The rainfall is once again chopping and changing from one run to another. I will have more on this in the coming evening update with the next video, but how does the rainfall unfold below?

SHORT TERM

Remains of a cloud band that brings a band of rain to WA on Monday moves through into western SA with moderate falls and local storms. Moisture lagging behind over the eastern inland likely to be picked up over the eastern interior on Tuesday into Wednesday.

Areas of rain with local thunder spreading through SA into NSW and QLD as early as next Tuesday with moderate falls. The rainfall would then move into VIC and the remainder of NSW and the ACT with light falls generally mid next week, with the high holding firm over the Tasman.

End of next week, there may be substantial cloud approaching WA with a deep moisture profile with widespread rainfall developing, some of that could be heavy, but as mentioned this morning, some other models support this coming through earlier in the period across the nation so that will be something to watch. Rain clears the east with only passing showers to follow if this is right later next week, but other models as mentioned have more rainfall across the nation's southeast and south.

MEDIUM TERM

A substantial cloud band is still there for the end of the month traversing the nation, and this has been a consistent theme on the models, the issue is timing on that cloud band moving through, whether it moves through during later next week or after the last weekend of May. The GFS the latter, the CMC and Euro say the former.

Noting a large cloud band over QLD and NSW with areas of cold rain moving through, wintry in the southeast with widespread showers. Notice the moisture still sitting south of Indonesia in a position that supports more cloud band and moisture intrusion into the jet stream as it bends through the nation.

Certainly, seeing as we move into early June, that the cloud bands will be running through the nation, the question will be the position of the long wave trough over the southern parts of the nation. There is a colder airmass across much of the nation, but it may be more stable than what has been previously indicated, so will keep watch. That may undermine rainfall chances.

The overall trend is for the Indian Ocean to play a bigger role from Winter onwards and Springtime, well rather than playing the hyperbole horn, pay attention to trend forecasts and ensure you don't buy into all the crazy predictions because they will be everywhere!