Heavy rainfall has been reported through the watch area for flooding over western QLD overnight with a few falls over 100mm being observed from outstations and many over 50mm. 100mm at Winton, not bad going for April and could break the monthly record.
This moisture and rainfall is spreading south, 5-15mm through parts of SA overnight with 30mm near the northeast of SA as well. Rain will continue today.
A front passing through the SWLD of WA later today will bring a burst of strong and gusty winds with showers and thunderstorms developing. This could bring the coldest weather of the year thus far for some parts of the southwest as well.
The front will rush across the Bight during Tuesday, and what it will do, will help to push the trough and wet weather over SA through QLD towards the southeast, bringing moderate to locally heavy rainfall through parts of SA and western NSW, but likely bypassing the southeast of SA and much of VIC at this time. This is why waiting before forecasting off the back of pretty colours on the data sets is important, we can see the rainfall is likely to deviate through much of the eastern inland and clear by mid week.
Another round of showers and storms will come through SWLD of WA during Tuesday afternoon and this front will run through the south of the nation, tapping into the residual moisture over the east leading to another band of showers and thunderstorms. A band of rain may form over parts of the southeast inland with additional moderate falls.
All of this activity will clear out from Saturday with a southwest to westerly flow to follow.
Across northern parts of the nation, we will still have above average moisture values, the dry season commencing with widespread showers over QLD and thunderstorms possible for the northern parts of the NT. Dry season could be well delayed this year for the north, which does mean that more moisture, heavy rainfall and cooler than average temperatures are quite possible through May for inland QLD, NSW and northern and eastern SA if this does continue.
Lets take a look - next video due out this afternoon after 5pm.
Rainfall Next 10 Days
Rainfall is forecast to be widespread, locally heavy with a flood risk over western QLD and through northeast parts of SA today with that moisture leading to a rain band developing over the remainder of central SA this afternoon. A cold front moving through the southwest of WA will see showers and thunderstorms developing this afternoon and evening with also, some moderate falls. The front will race across the south of the country triggering showers but it won't be until it gets into the Bight that we could see more extensive shower activity develop for parts of Ag SA and then rolling through western and southwest NSW into northern VIC and across much of the eastern inland. The rain tending lighter and patchier the further east you go through NSW and QLD. Another front will move through SWLD of WA on Tuesday with further showers and hail about coastal areas. The front will then move through to the southeast by Thursday with the moisture lingering from this current event being lifted into widespread showers and thunder with additional moderate falls. Over northern tropical areas of QLD, there could be some falls over 100mm during the coming 36hrs. The rain is forecast to ease mid week for the region but the showers will not clear and they may extend back over the northern Top End.
SHORT TERM CLIMATE DRIVERS
SOUTHERN ANNULAR MODE - Currently neutral and turning negative briefly, however likely to remain neutral overall during the first week of May. This may assist in more westerly winds developing over southern parts of the nation. This may also allow the jet stream to become a little more wavy and spreading the moisture south and east from the tropical north. If we can get moisture over the Eastern Indian Ocean, this may support more widespread rainfall across the country again.
Thunderstorm Forecast Monday
Thunderstorms will continue over large parts of the Outback with an upper low moving through SA. The thunderstorm focus will start to move east into western NSW and VIC during the day with gusty winds and heavy rainfall possible. Thunderstorms also possible through the morning in southern WA as a strong front passes through, these could be gusty.
Thunderstorm Forecast Tuesday
Thunderstorms are forecast to contract slowly east as a trough begins to move into the eastern inland. Severe thunderstorms are likely to be further north now as the timing of a front looks to knock out the most potent humidity and combination of atmospheric dynamics further north into northern NSW and western QLD. Heavy rainfall and damaging winds are likely. Over the north, late season rainfall continues via scattered storms, more widespread over the northeast tropics. Another front could bring gusty storms to the southwest of WA with small hail.
Thunderstorm Forecast Wednesday
Thunderstorms will continue through the western parts of QLD extending northwards to the northern tropics and southwards into northern NSW clipping NE SA. Thunderstorms may turn severe with heavy rainfall and damaging winds the main concern.
Thunderstorm Forecast Thursday
Thunderstorm are forecast to continue along a trough over the eastern inland of the nation leading to widespread rainfall as well. Thunderstorms are forecast to be gusty with damaging winds about. Heavy rainfall may also lead to flash flooding. Thunderstorms are forecast to be active over northern areas of the nation with dry season starting out humid and wet for some.
Thunderstorm Forecast Friday
The front and trough from the Bight will add supportive wind fields and atmospheric dynamics to produce scattered storms over a wide area of the east with moisture lingering from the current event being lifted by a wave of unstable weather moving east. A dry line may establish through the inland and could be the focus of strong storms with damaging winds and heavy rainfall leading to flash flooding.
Thunderstorm Forecast Saturday
A dry line will continue to move through the interior of the country with a band of rain and thunderstorms moving north and east through the eastern inland. Storms could be severe if there is sufficient surface based instability but most storms should be elevated and gusty with moderate to heavy rainfall possible. Storms will continue over the northern tropics mainly during the afternoon and evening.
MEDIUM TERM - May 2nd - 9th 2022
Rainfall generally looks to be falling between now and the end of the month and residual rainfall from this week I have taken off the chart to focus on where the next event will come from. Watching the northern tropics, over the west offshore WA for the jet stream to drag moisture into the nation and in the east, we could see another wave of onshore winds and showers with the SAM turning back positive again, but signals are not especially high.
Temperatures should start to improve after a cooler end to April for many over the inland and a cool start to May. A front and new wave of low pressure with a jet stream could bring in some warmer air through the central interior and across to the southeast and eastern inland at the end of this week, but the cooler days will linger in advance. So there may be a lot of blue on the board but improving temperatures are likely from about the 3rd onwards for large parts of the east, cooler for the west.
More coming up this afternoon after 530pm EST. Lest We Forget.