Dry air has set up camp over Australia for the next little while.


The continent is currently under a blanket of dry air with very little cloud cover currently visible away from coastal areas of the country.

The dry air is extensive and runs through all levels of the atmosphere through the interior of the nation and back through WA, hence the lack of cloud cover. You can see an upper trough analysed over inland WA, but with little moisture, all you have is high cloud.

Fast moving cold fronts to the south of the nation is keep the high pressure anchored over southwest WA ridging through SA and into NSW.

Short to medium term forecast modelling continues the run of dry air over large parts of Australia (denoted by the brown tones). This is expected to be in place for the most part into early May.

Coastal areas will see modest moisture from time along cold fronts through the southern ocean, bringing showers.

You can see that on Tuesday with the moisture really sticking to southern coastal areas, and you can clearly see the impact of that dry air over inland areas, no cloud really in sight!

The bulk of the deeper moisture will remain over FNQ and the NT (denoted by the green, yellow and orange shadings). That is being lifted by a tropical wave bringing widespread rain and thunderstorms across the region.

And with that tropical wave, some areas around Cairns have received 300-400mm of rainfall

A cloud band will develop later this week thanks to an upper trough approaching from Central Australia, but due to the lack of deep moisture through central and southern QLD, not much rainfall will develop for inland areas this time around. It is as the upper trough runs into the deeper moisture, rainfall will become more widespread.

Future IR satellite shows that cloud band developing in response to the upper trough moving into the region and the strong upper level winds moving through eastern Australia with the long wave south of the nation meaning, the bulk of the rainfall will move swiftly east and north of NSW and VIC/SA.

Rainfall will remain largely in QLD and those areas that are exposed to a westerly wind regime through southern Australia.

With the dry air that is depicted in the video at the end of the post today, you can see the dry air is going no where.

So for now, the fast zonal pattern with embedded cold fronts will continue to the south of the nation, helping to hold high pressure over southern inland Australia, keeping the dry air in place for another 10 days or so.

We need moisture to pick up ahead of cold fronts coming into WA, through the Indian Ocean, and as you can see there are no signs of that right now. Once we see a pattern flip you will see and hear about it here first.

Precipitable Water Values for Thursday and indeed this chart below is largely unchanged with the brown shadings remaining in place right through until the end of the month at this stage.

Precipitable water is the depth of water in the atmosphere, if all the water in that region were precipitated or squeezed out by clouds as rain.

If you want more detailed forecasts on your backyard or property, want to have a chat with me about weather in the short, medium or long term, email me at karllijnders@weathermatters.org and we can sort something out.

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