The forecast is becoming more complex by the run it seems, with a large scale high still set to dominate the weather across much of the nation with a dry airmass, clear skies and light winds to feature through inland areas and indeed mostly dry weather for the coast south of about Taree, but even along the North coast, the rainfall is hard to find.

We see showers increasing from Thursday over northern coastal areas with the flow shifting easterly, but the weather is forecast to be dry elsewhere with high pressure still in control, leading to the coldest morning of the year for many over southern and southeast areas of the state. Frost may be severe nearby the ACT with temperatures as low as -5C possible.

Warmer and more humid days are forecast to develop from later this week and this will mitigate the frost risk overnight. A northeast flow is forecast to develop over the weekend. The weather becoming increasingly wet as a result along the coast with moderate to some heavy falls emerging. A trough deepening over the northern areas could see rainfall increasing further under such circumstances but the idea is not off the table.

Some chance through the weekend, some showers and thunderstorms may develop along another upper trough over western areas of the state, but this has been hot and cold in the modelling and will take a few days to iron out whether this is a real threat. This would mean another wet spell would be on the cards for many areas of NSW from the weekend into next week.

All of a sudden we have gone from a drier period through the inland for the week to now looking at unsettled weather developing over the weekend and increasing in coverage as we see cold fronts running into the moisture next week leading to more unsettled weather.

So maybe further headaches for many trying to plant and protect crops, from frost later this week to possibly moderate rainfall for a number of days over the weekend into next week.

Let’s take a look


Rainfall Next 10 Days

Rainfall is forecast to be very lean through the next 2-3 days for inland areas, really until the end of the week is fair, with ridging in place. The onshore winds on top of a high moving through Tasmania is forecast to lead to widespread showers developing from Thursday and this may lead to widespread rainfall developing into the weekend with some moderate to heavy falls along the coast. The moisture may spread inland as mentioned through the video to most northern and central districts across the weekend and that could see more rainfall on the cards with moderate falls possible, but not all models are on board with this idea so keep watching the updates in the coming 2 days. With frontal weather sliding southwest of the state, this could see a decent slab of moisture also enter from the jet stream leading to more rainfall emerging through next week, combined with the moisture in place via the easterly winds. Overall, the pattern is tending wetter for many areas, heaviest falls still look to be up along the North Coast, but other areas could do fairly well with moderate rainfall over a number of days in warmer and more humid air once again and better rainfall chances coming up for the end of the month.

An upper trough forming over the Central QLD coast could lead to heavy rainfall developing about the coast in the presence of the trough from the weekend and into next week. Some areas on and to the east of the Great Dividing Range and the hinterland should see the best of the rainfall. Moisture may spill over into the northern inland with some scattered showers developing over the weekend, but the coverage is not quite clear yet. Drier weather develops here from later next week as winds tend westerly.

The showery weather will also develop along the coast but the falls likely lighter in coverage south of Ulladulla with the flow a little more stable closer to the high-pressure system. As mentioned above, some of the moisture may sweep over the Great Dividing Range leading to showers developing over the weekend with mostly light falls at this time.

Frost Risk Forecast - Wednesday through Saturday

A drier airmass is forecast to settle in from Monday and with clearer skies and the high-pressure ridge moving in, there is the chance of frost developing. The peak of frost is forecast from Wednesday and Thursday and may persist into the weekend but depends on the position of the high-pressure ridge to the southeast.

Medium Term - May 24th-31st 2022

Rainfall Anomalies

Rainfall anomalies starting to increase over the south and southeast inland as a long wave trough moves into the eastern portions of the nation, lifting all the moisture being drawn in via the northwest flow aloft, leading to larger rainfall developing. Showers may be most frequent over the far southwest and later in the period as the westerly wind belt increases its coverage over the nation. That westerly wind regime will bring drier weather to northern and eastern parts of the country.

Temperature Anomalies

The warmer bias looks to peak through towards the end of the month over the end of the month but understand that the temperatures will remain below average through this time over in the west and spread over the south of the nation as we move through the last few days of the outlook. So this period will be one of transition and the colder weather will move from west to east. The weather over northern Australia looks to be well above normal.

DATA - Refer to video for more information and the model comparison and context about all the forecast products you see from me.

00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

More details can be found in the video but watching the remains of the severe weather event for inland WA which is producing significant rainfall and flood risks. We are also watching the chance of severe weather developing along the Central and SEQ coast this weekend with moisture moving inland producing widespread showers over the inland of NSW and QLD with light falls, can this make it into SA and VIC? The strongest cold fronts of the year for the SWLD of WA from Sunday and another next week, more moisture being drawn into these features could bring rainfall into the interior and possibly into SA and VIC this time next week. Some better rainfall chances exist for the southern Australia to finish the month. The rainfall and overall weather distribution adopting a cooler season look.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Dry and colder air is filtering through southern and southeast Australia and you will feel that and see that, with cold nights developing with frosty mornings on the way and clear sunny skies for much of SA, VIC and NSW. The moisture deeper over the inland of WA will become eroded and also stall out by the ridge bringing in the drier and stable air over the southeast, allowing for the moisture to sit over the western interior through to the weekend, waiting for the next system to lift into meaningful rainfall. The moisture streaming throughout the inland of QLD and into NSW with easterly winds, heavy showers for the coast, some of that moisture drifting into the interior may bring up the chance of wet weather this weekend. Then into the medium term, moisture surges in from the northwest of the nation through the southeast in advance of a developing long wave trough and a series of fronts. This offers the better rainfall chances for southern Australia.

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 Euro- 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 rainfall forecast from the GFS is low confidence and more details on rainfall and modelling comes your way later this evening.

More coming up from 8pm EST with a look at the models and rainfall.

46 views2 comments