SA - SHOWERS DECREASING TONIGHT, FINE UNTIL ANOTHER STRONG FRONT ARRIVES EARLY NEXT WEEK WITH RAIN

ANALYSIS

Showers are in the process of contracting to the southeast of the state tonight and clearing during Thursday, as a front and low moves east of the state and high pressure begins to build back over the state.


A stronger high pressure ridge will keep things dry until about Saturday and this is when we start to see the next system beginning to move into the west of the state.


SHORT TERM

The feature of interest is the strong cold front approaching the state from the west from Saturday. Ahead of it, stronger northwesterly winds and a warmer airmass will replace the colder weather we have been having since the start of the month.


A band of moderate rainfall will move into Ag Areas during Sunday and slowly move into the eastern districts by the time we get to Sunday afternoon with the rain breaking to showers behind the front with a cooler shift to a westerly winds.


Further showery weather will be expected in the unstable westerly flow through much of next week with another front forecast to move through from Thursday.


LONG TERM

That front on Thursday will bring further showers and local hail and a much colder shift, with a new ridge out to the west helping to propel the colder air north eastwards across the state.


Some interest lay in the orientation of the ridge as that begins to move through the south and southwest of the nation, the further north that ridge sits, the more likely further showery periods are expected with frontal weather passing through an unstable westerly wind belt.


AREAS TO WATCH

Also of interest is the potential for moisture to pour southwards into the eastern and southeast inland of the nation with an upper trough moves over Central Australia leading to a broad band of cloud with widespread rainfall developing over QLD, NSW eastern SA and VIC. This has appeared on some of the global models for the end of the month but the forecast confidence remains low.


The Southern Annular Mode remaining strongly negative could shoot up colder air in the medium too, meeting the moisture surging southwards into the country leading to those rainfall chances, but with the SAM negative for the period, frontal weather is also likely to feature for southern Australia


WEATHER VIDEO PM - WEDNESDAY 15TH JUNE 2022

FORECAST

Rainfall Next 10 Days

Rainfall has started to ease as the weather clears into Victoria tonight and the ridge rebuilds over the state during the remainder of this week. The next rainfall opportunity comes in association with a strong cold front that moves into the west of the state during Saturday. There will likely be a robust injection of moisture from the Indian Ocean that will lead to a large cloud band moving through the continent. Rain with moderate falls are forecast along this feature as it moves through slowly through the southern and southeast areas of the state. Most Ag Areas are forecast to see atleast 5-15mm from this event, possibly more. Further showery weather is expected next week with fronts embedded in the westerly flow to keep the light falls going. A stronger front may bring moderate rainfall during Thursday next week which may then move further north and east than the earlier fronts, so this system may need to be reviewed, as it could spark a larger rainfall event over the state with moisture surging south out of the tropics.

A closer look at the Agricultural Areas and frequent frontal weather passing through will bring the light to moderate rainfall, the rainfall heaviest with a feature developing through later Sunday into early next week with the strong front moving out of the Bight.

MEDIUM TERM

June 22nd-29th 2022

Rainfall Anomalies

I know it may be frustrating to see a lot of white on the board but until there is higher confidence on that northern rainfall event, the nation as a whole look to be sitting at seasonal rainfall expectations through the end of the month, with once again the caveat being on that rainfall emerging over the tropics in medium term in future data runs, so watch closely.

Temperature Anomalies

Cooler bias strengthening for parts of the eastern inland once again with a cold pool of air riding behind a cold front later next week then sitting over the eastern interior, continuing to buck the trend of climate models that were suggesting somewhat warmer conditions than what we have observed in the east. Seasonal temperatures out west but the warmer weather over the northwest will continue with dry air.

DATA - Refer to the video for more context on the short and medium term. Notes will be provided under any of the graphics below to highlight weather of concern.


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

Refer to the video for more information on the short and medium term and also the current trend for rainfall spreading across the nation in the medium is of low confidence. The southeast is looking the wettest as we move through the coming week with frontal weather to stay there.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture over the west of the nation has now migrated over the southern parts of the country and into the southeast with troughs and fronts running into this leading to widespread falls in the short term. As mentioned this morning, the position of the trough and upper features over northern parts of the country in relationship to the very high moisture load over the northern waters will lead to higher rainfall chances over the north and east, but where....no one can tell you so keep watching.

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 - more on this coming up at 8pm tonight but the rainfall numbers into the medium term are low confidence and the system in the short term also of low confidence passing through SA into VIC/NSW mid next week.

More coming up from 8pm EST with a look at the models and rainfall, I will only share information that is in reasonable agreement as too much is too confusing and I only want to share what is plausible at this time, so stay tuned for that.


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