FRIDAY EVENING WEATHER - ANOTHER COLD NIGHT ON THE WAY EAST. SHOWERS INCREASING SOUTHERN AUSTRALIA.

OVERVIEW

Another very cold night on the way for the east, the west is drying out as high pressure ridges through, most locations are dry tonight with sinking air motion and dry air combining together to bring the clear skies and light winds.


A weakening cold front passing through the south and southeast of the nation over the coming days will spark the weather of interest nationally with windy weather and showery periods with local hail and thunder about and a cold airmass surging through.


Some severe weather risks remain along the front as it passes through with damaging winds over elevated terrain through the southeast inland.


SHORT TERM

So the cold front will bring the chance of showers and a few claps of thunder to the south of SA Saturday before the systems sweeps into the southeast districts. The better coverage of rainfall will be found over the southeast areas of SA before moving into southern VIC into Sunday with a broad band of light to moderate rainfall then stacking up against the western slopes of the Great Dividing Range in southern NSW.


Another trough out west will approach the west coast of WA during the latter parts of the weekend with a batch of showers and storms moving through. The rainfall trends are uneven at the moment, so expect less widespread rainfall as the last system, but follow up rainfall for many of you through the SWLD is quite possible.


An upper low is expected to form out of a trough through Central SA and NT with that system forecast to move eastwards into the modest moisture coming into feature via onshore winds over QLD and NSW may see a batch of showers and storms form mid next week.


With the SAM tending more volatile in the short term this will push the westerly wind belt further to the south of the nation next week, once again disrupting the flow of fronts out of WA into southern and southeast Australia.


LONG TERM/AREAS TO WATCH

The SAM trending negative is still an idea on the table for the end of the month, but we have got a period of positive SAM in the coming week and that will see a much drier spread now for southern Australia.


With that phase underway, we may see rainfall increase over normally dry areas of QLD and NSW on and east of the divide.


There are no changes to the Indian Ocean influence either, the negative phase is still developing and will come into play when other climate drivers move into phase.


WEATHER VIDEO PM - FRIDAY 15TH JULY 2022

FORECAST

Rainfall Next 10 Days

So, rainfall is starting to shift further south from SA, VIC and WA as we see the positive SAM phase return for a period in the coming 5 days, and this lifts rainfall up over eastern NSW and QLD but still not to levels expected seen from previous SAM phases, at this time. Showery weather this weekend looks to be the most productive event of rainfall for southern and southeast areas of the nation. The wet weather clears early next week with high pressure sitting over the southeast areas and settling in over TAS and becoming slow moving. There will be another trough coming into WA with light to moderate rainfall about Sunday into early next week. Further frontal weather is expected to pass through the southwest of the nation, but these may be in a weakening phase due to the SAM phase. Rainfall of interest is back on for parts of QLD and NSW next week but a reminder, the confidence in this forecast is low.


SOUTHEAST AUSTRALIA

A broader look at the southeast and as mentioned earlier today, the westerly wind regime is set to impact SA, VIC and southeast NSW west of the divide with showery periods with a few moderate falls passing through. Then we see the rainfall easing over the southeast as the high pressure moving in from the west begins to shift into the southeast of the nation and then showers begin to redevelop over the east coast of NSW, heaviest over the coastal fringe north of about Sydney at this time with an upper low moving through southern QLD. Then some patchy rainfall is expected to pass through northern areas mid to late next week. Further frontal weather looks to apprach the southeast states at the end of the period.

SOUTHERN AUSTRALIA

Showers are expected this weekend but then conditions begin to dry out through the bulk of next week as large high remains in place, ridging through the state and combining with drier and warmer air to produce somewhat early Spring like conditions for some areas. Some moderate falls this weekend is possible with local thunder producing the better falls south of Kingston as well as the Adelaide Hills region

EASTERN INLAND

The upper trough coming through next week is expected to kick off patchy rain or showers with some thunderstorms possible, but the confidence in rainfall spread is very low and so use this as a guide, because your forecast will change, and the data sets are quite volatile at the moment. Until then, the weather is forecast to be dry throughout the weekend.

NORTHERN TROPICS

Dry for the NT, maybe a few showers in Arnhem land in onshore southeast winds, showers look to increase over parts of Cape York and down the eastern seaboard with onshore winds redeveloping. An upper trough working through southern and central QLD could see showers increase further in coverage and some thunder is also possible.

WESTERN AUSTRALIA

The wettest part of the nation is forecast right down here in the SWLD. A few systems to pass through will bring moderate rainfall. The next system on the board, expected to cross through the SWLD during Sunday and clearing Monday. Another front is due mid next week, and a stronger system is due in later next week into the weekend. The bulk of the Ag Areas should see some reasonable follow up rainfall which will support the improvement of the soil moisture.

THUNDERSTORM FORECAST

Thunderstorm Forecast Saturday

Thunderstorms on the northern flank of a weakening low are likely to come through on an associated trough with mainly moderate rainfall and no severe weather is expected. The winds could be strong and gusty with thunderstorms in the southeast districts of SA and into western VIC, but damaging wind advice are in place for strong gradient winds ahead and with this front already.

Thunderstorm Forecast Sunday

Cold air sweeping through the southeast of the nation and a wave developing on a cold front passing through the region will add enough support for a few cold air thunderstorms along the band of rain coming into southeast NSW and through coastal VIC in the showery streams. These may contain strong squalls and small hail over southern VIC.

WEATHER ISSUES

Frost Risk Forecast Saturday Morning

Frost is expected to be widespread and heavy to severe once again over the eastern inland of the nation especially over the Great Dividing Range from the VIC border through to southern QLD and onto the plains through northern NSW and southern QLD. Frost is also likely to develop over Central Australia once again, nosing into the APY Lands and possibly eastern WA during the morning. There is a low chance of frost over in the SWLD of WA, at this stage cold night on the way but the risk of frost on current guidance less than 20%.

Freeze Risk Forecast Saturday Morning

Freeze conditions once again likely from Cooma through to Goulburn including the Canberra region and points west to the Yass Valley and along the Central and Northern Tablelands, where temperatures are forecast to get down to <-5C once again for many. Cooma recorded -9.5C this morning at the AP and -7.5C in some Canberra suburbs.

Damaging Winds Risk This Weekend

Strong gradient northwest winds are forecast to bring warmer weather for some on Saturday, but the risk of damaging winds will continue to evolve as we track into the evening and peak later tomorrow night into Sunday. Strong squalls with showery periods moving up from Bass Strait is possible in southern VIC on Sunday before that eases later Sunday.

Small Hail Risk Sunday

A cold airmass with showery air will see hail becoming a risk for parts of the southeast, more likely during Sunday afternoon and evening across eastern Melbourne through to West Gippsland into the Yarra Ranges. No severe weather expected.

CLIMATE DRIVERS - SOUTHERN ANNULAR MODE - VOLATILE.

The SAM has shifted back to a weak positive phase overnight, in one run of data the shift has now pushed back the shift to the neutral then negative phase towards the end of the period. This will now open the door for that rainfall event developing over the east of the country and push the rainfall spread over southern Australia further south for a period.

MEDIUM TERM FORECAST

July 22nd - August 7th 2022


Moisture Watch Next Week

The moisture spread has been greatly impacted by the developing SAM phase next week which will shunt the moisture coming out of the Indian Ocean further south and west of the nation before it turns back towards Australia for the end of the month into early August. A moisture plume over the Coral Sea will mainly stay offshore but part of it could linger over Central QLD with some higher chances of rainfall likely about coastal areas.


Rainfall Anomalies Next Week

A drier bias returns to pockets of SA and VIC only in response to the westerly wind belt being shunted southwards next week with the lingering impacts continuing into this period, but the rainfall numbers could start to increase over the west and then spread into southern and southeastern areas of the country as we pass into the end of the month. Seasonal rainfall is expected most elsewhere at this time, but the wildcard will be the eastern areas of QLD.


Temperature Anomalies Next Week

A nice warm up across the nation now looks too creep across the country thanks to the low pressure that is forecast to develop over eastern QLD with an upper level system. A strong high next week will linger over TAS before slowly moving offshore to the east. This will lead to a northwest flow dragging in the warmer air into SA and VIC with the warmer bias continuing out west in advance of cold fronts clipping the SWLD.

CLIMATE DRIVERS - SOUTHERN ANNULAR MODE - VOLATILE.


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

Refer to the video for more information and the model comparison and context and to make sure you understand the reasons for the low confidence forecasting and why the forecasts keep changing.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture content through the nation has come down a bit through next week from where it was earlier in the week because of the developing block over in the east, interrupting the flow pattern out of WA. The moisture building with an upper trough sitting offshore QLD could swing towards the mainland next week so watch that closely, as the ingredients are there for a severe weather event, models mainly keeping that offshore. Otherwise, it is struggle street to get much in the way of meaningful rainfall out of the westerly wind belt with the signals are for that to sink southwards for next week, but it may start to turn back towards the nation at the end of the period to kick off August!

00Z ICON - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - 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 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 and the state-by-state fly around!

More coming up from Saturday morning - time for a gin and make sure you get onto the Facebook Members only page!



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