SATURDAY MORNING WEATHER - SHOWERS INCREASING FOR THE SOUTHEAST TONIGHT. RAIN BREAKS OUT INLAND.

Updated: Jun 25

ANALYSIS

Certainly, looking very quiet nationally today which is probably not a bad thing with many people moving about with school holidays underway in many states. The Winter Break period ongoing for large parts of Ag Australia with just some frontal weather grazing the southern coastal areas as the westerly wind belt continues to sink southwards as the SAM turns neutral.


SHORT TERM

Showers will redevelop over the southeast with a weakening cold front passing through the westerly wind belt with a strong northwest wind shifting colder southwesterly. The showery weather will not extend that far northwards with the pattern shifting offshore the east coast by Sunday morning.


The rest of the nation is quiet before we see the upper trough deepening over WA and this becoming slow moving through next week with moisture becoming deeper from the upper-level northwest winds that form in advance of the trough. There is some strengthening of the signals that the rainfall may be further northwards through QLD and the NT with a lesser chance now of the rainfall spreading southwards.


But in saying that, some of the models have been hinting at the idea of a cut off low developing over the southeast of the nation with increasing showery coverage due to this feature.


LONG TERM

The moisture is still forecast to meander around the north of the nation but may be held at bay and block by high pressure from entering southern and southeastern Australia.


That opens the door for further above average and possibly out of season rainfall and humidity for the NT and QLD.


Showers may also develop along the east coast in response to the developing easterly flow and that may combine with the trough approaching from the interior to see moderate rainfall emerge.


The west remains dry for a while for now, with a large-scale area of persistent high pressure.


AREAS TO WATCH

The SAM may turn positive, but it looks to turn back to being negative through the first week of July, with some member suggesting another robust period of westerly winds developing from the second week of July, so rainfall chances come up for the SWLD of WA and then extending east along the coast.


The moisture and upper-level disturbance over northern and northeast Australia may also spread further rainfall chances through that region.


The Indian Ocean Dipole in negative phase is still in progress and this is NORMAL for this time of year to have a quieter spell. It will return with force through late Winter into Spring!


SPECIAL VIDEO ANALYSIS - SATURDAY 25TH JUNE 2022

FORECAST

Rainfall Next 10 Days

Rainfall is very tricky to pin down for northern areas and will remain to be of a challenge in response to the ridging that is riding through the nation but also the timing of frontal weather over the south in relation to the upper trough over the north, also causing havoc with the moisture and spread of rainfall over northern Australia. And will we see another upper-level system distort and disturb the rainfall spread over inland QLD? Confused yet!? That is because it is. The complex pattern is allowing for the weather to dry out across the country's west and central areas for now and below average rainfall for southern parts of the country as the westerly wind belt starts to move away. The overall pattern for northern and eastern Australia lends itself to producing above average rainfall with moisture and unsettled air continuing to lurk so watch closely.

THUNDERSTORM FORECAST

Thunderstorm Forecast Saturday

Nil Thunderstorms at this stage, but watching the potential for cold air to drift into the southeast, that could promote some local hail and thunder. Possibly a storm over the waters north of Australia too.

Thunderstorm Forecast Sunday

Nil Thunderstorms....for now! The upper trough approaching later in the weekend could kick off storms over SA and or QLD through the afternoon so keep watch.

Thunderstorm Forecast Monday

The development of a trough over the northern parts of the nation could start to see scattered showers and thunderstorms emerging later Monday into Tuesday.

Thunderstorm Forecast Tuesday

Thunderstorms are possible over a broad region of the NT and QLD, but the forecast confidence is low, and this will continue to shift as the guidance improves.

Thunderstorm Forecast Wednesday

Thunderstorms are still possible over a broad area of northern and northeastern Australia with a broad trough and deepening moisture but the coverage within this broad zone is uncertain and will likely shift in the coming days. If a strong cold front approaches the southeast of the nation, there is the chance of thunderstorms with the boundary as that moves through.

MEDIUM TERM

July 1st - July 8th, 2022

Rainfall Anomalies

The wet bias is still being held up on most of the broader data sets leading to a wet few weeks for parts of eastern Australia, if the easterly winds and troughs combine in the right region. The drier bias continues for the west, though marginal, may be a signal of a period of quieter weather continuing for the coming 1-2 weeks. Seasonal most elsewhere for now, but with higher pressure moving over the southeast into early July, we could see some drier weather develop over the southeast inland and Tasmania.

Temperature Anomalies

A colder bias is developing on the charts in response to the colder air that is beginning to appear on most of the modelling at the moment, leading to that cold and drier air becoming trapped under a large Winter high over the Bight. If the high remains slow moving in the same region, then most of the country could go from that humid and warmer look that brings the rain, to a colder and drier outlook for the first week of July.

CLIMATE DRIVERS - SOUTHERN ANNULAR MODE - SAM TURNS NEUTRAL.

We can see that the negative SAM is nearly over with a neutral phase likely to develop through the weekend and into next week. Note that the lag impact of the phase shifting is about 3-5 days so you may start to see the rainfall return to the east coast mid to late next week as the SAM shifts into positive territory. The models are struggling with this component too.


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


00Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

Refer to the video for more details as I could write a tome here this morning and I think it needs words and pictures together so take a look at the video at the top of the page.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Refer to video for further details and explainer on the model spread and the confidence in forecasting. You can find that at the top of the page.

00Z GFS - Rainfall Accumulation - Next 10 Days - LOW CONFIDENCE

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days - LOW CONFIDENCE

Refer to the video for more context and analysis

00Z Euro - Rainfall Accumulation - Next 2 Weeks - LOW CONFIDENCE

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

More coming up this evening if time allows and I can get from Melbourne to Canberra with no delays at the airport! Smart to fly during school holidays...NOT!