SA - SHOWERS FOR THE SOUTHEAST, A COUPLE FOR OTHER COASTAL AREAS THIS WEEK. DRY INLAND FOR NOW.

OVERVIEW

The pattern is typical for Winter Break conditions where the westerly wind belt begins to retract southwards as ridging begins to beat the rain bearing winds away, this is standard after an active period of frontal weather. We are still seeing relatively light rainfall for many coastal areas, especially in areas facing west into the cross shore flow.


The pattern should remain this way through the weekend, with a stronger front glancing our region but likely peaking over VIC, but it is an interesting elongated system running east west and these features (we get 1-2 a Winter) can cut off into low pressure systems without much notice so I will be watching.


SHORT TERM

As mentioned not a great deal of change for the state and not a great deal of change inland either, really stagnant pressure pattern, but it is not a blocking pattern, it is mobile but low amplitude. That means not a great deal of change from day to day.


In terms of inland areas, remaining fine and mild with above average temperatures after colder starts with the subtropical ridge over head, another hallmark of Winter.


Though far northern and northeast areas should pay attention to the forecasts as we see an upper trough moving over the state from later in the weekend and into early next week. That could see cloud increasing and rainfall developing north and northeast of the border.


LONG TERM

The main area of interest in the longer term is that upper trough over the northeastern inland of the nation and whether that moves south and southeast into NSW and or into SA remains to be seen.


How long does the rest of the nation stay dry for!? Well that is an interesting proposition that I will touch on during the coming 2 days, looking into the medium term, the Indian Ocean does go quiet and referring to this post gives great insight into that. But with the warmer waters about, it is likely it will not last as long as last year, I do think we see the rainfall return from the west and northwest into early July.


AREAS TO WATCH

Certainly the dominance of the drier air and high pressure over the northwest of the nation and southern areas through the end of the month and into early July. The pattern may be disrupted however, with a significant risk of widespread moisture being drawn back into the nation from the west with a deep jet stream returning ahead of frontal weather as the SAM turns negative again.


Moisture lurking over northern parts of the nation signifies the first part of the shift to the wetter end to Winter and Spring is on the way, with that being an element left over from the prolonged La Niña


WEATHER VIDEO PM - TUESDAY 21ST JUNE 2022

Rainfall Next 10 Days

Rainfall forecasting is fairly standard for this time of year where we see Winter Breaks where rainfall eases in coverage and a shift to ridging moving south of the state sees the drier bias return for a period, before the next surge of westerly winds return. So showers, while they will be about at times, the rainfall within seasonal expectations and the coverage not extending inland a great deal. Use the rule, the further south you go, the wetter you will be. As you head into the north, the weather is drier and completely dry quite frankly through early next week for much of the state. The wild card is that upper trough over the northern inland from later in the weekend into early next week, whether that can bring rainfall back southwards into the state, but it is low confidence forecast as I have been parroting at length through the past week.

Rainfall Next 15 Days

Drawing the rainfall further along, you can see that the east of the state may be dealing with moisture spilling over from the secondary rainfall event potential and zooming out helps to contextualize the risk over the course of the next fortnight.

MEDIUM TERM

June 28th - July 5th, 2022

Rainfall Anomalies

Rainfall anomalies are running high over the eastern third of the nation with a marginal risk extending back to the NT and back over the southeast of the country with an upper trough and deepening upper low wafting around, but the forecast confidence is quite low. The SWLD could see further drier weather with high pressure stuck in the region as a blocking upper-level trough sits over the east.

Temperature Anomalies

Temperatures are moving around a little bit in response to the developing troughs over the east which may pull in warmer and soupier air, but with the rainfall forecast, seasonal weather is expected in terms of temperatures. Over the north the temperatures marginally above normal and elsewhere, the weather is seasonal, but a lot is dependent on the weather situation moving forward.

DATA - Refer to the video for more context and information to explain the forecast charts above and the data below


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

Once again, the big feature to watch is the system over the north and east and the westerly wind belt impacting the south of the country.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture over the north of the nation without the upper-level trough is of significance and highly anomalous and opens the door to a widespread and heavy rainfall event, if the low pressure can draw it south from next week. That moisture persists throughout the period into the medium term. Elsewhere, the values are what you would expect at this time of year.

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 GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - it may look very exciting/concerning for many of you related to rainfall, but it remains of low confidence and so please make sure you refer to the video at the top of the page for more context for the rainfall totals into the coming 2 weeks.

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

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