The wet weather keeps on keeping on for the north of the country, particularly the eastern Top End and parts of Cape York where a moist and unstable airmass is in place leading to significant late season rainfall, some areas have seen 100-200mm in recent days and this is important to watch for rainfall potential down the track for some parts of the country. It is all beneficial for these areas with a failed wet season being observed for many locations away from the northern and western Top End and Kimberly.
Looking further south we are feeling like we are back in March in some areas with a late season burst of heat, Summer arriving late for many people. It is not uncommon to get a late season burst of heat, and it usually is an indication that a response, in the form of an Autumnal Break is not too far away. It appears that could come in stages this year as outlined a month ago in the Autumn Break analysis.
Referring to the satellite you can see the cloud band emerging as the ingredients for that Autumn Break begin to show up in real time. Moisture streaming into the jet stream from the Indian Ocean is forecast to then progress eastwards and be picked up by a trough and cold front through Monday and Tuesday with some areas possibly seeing reasonable rainfall for a quite a few locations in the southeast inland as well as part of inland WA where another trough may linger.
SA still looks to split the difference so to speak, with a ridge cutting off the rainfall and lifting mechanisms out of phase.
The remainder of the eastern inland to the north of this feature could stay relatively dry and warm as we progress through the next few days, namely north of about Broken Hill to about Dubbo and Sydney where the air is more dry and stable.
Moisture from the tropical expression over northern Australia still looks to be drawn into parts of the eastern inland as well as via easterly winds that develop over NSW and QLD thanks to a positive SAM phase. This may start to feed a trough deepening over the central and eastern inland with another cloud band developing for inland SA, NSW and QLD.
Yet another system is set to emerge over WA through the latter part of this week and this is the feature to watch. A long wave trough moving into the west, ramming into the moisture in place while drawing in additional moisture from the northern tropics, will see a hefty and more robust cloud band form along the pre frontal trough and then front that moves through.
The weather is progressive but not rapidly moving from west to east so this system will hopefully bring many areas the break they need through SA and VIC in particular.
There is the chance of further rain and storms over the northern tropics with another wave passing through which could seed the jet stream and bring up rainfall chances over inland areas once again as we head into early May.
Lets take a look
Rainfall Next 10 Days
Numbers look to be coming up over large parts of the nation as we see 2 events on the board. The first event looks to unfold from later today with a band of rain developing over eastern SA and into VIC with patchier falls back over inland WA with another cloud band. We will also see lingering rain and storms over northern Australia with the disturbed weather slowly contracting eastwards. The rain and storms over the southeast could become heavy at times over eastern SA, Victoria and southern NSW into the ACT through to mid week before the system slides off into the Tasman. More moisture being drawn in from the easterly winds in the wake of a southeast to easterly change will help to bring showers to the east coast with moderate falls possible for the NSW and southeast QLD coasts. Over northern Australia the showers will be mainly found over coastal areas of the Eastern Top End and Cape York into FNQ with some heavy falls possible about the wet spots exposed to the easterly flow. Another pulse of moisture will be drawn in via the northwest winds over WA and we could see some heavier rainfall return again for the SWLD with that change moving through later in the week into ANZAC Weekend. At this time, another burst of moisture will interact with an upper disturbance over the eastern and central inland of SA through NSW with rain developing for a wide area but pinning down who gets what remains unknown at this time. But I am drawing in light to moderate falls with that feature from the weekend with some inland areas looking to get above average rainfall from the event (given that it should be mostly dry this time of year). The rainfall from this event could be sufficient to bring the Autumn Break for many in Ag Australia, especially in central and eastern areas.
Thunderstorm Forecast Sunday
Thunderstorms continue mainly about the Gulf Country of NT and QLD. Thunderstorms may be gusty at times. A weak middle level cloud band may form on Sunday afternoon in WA and graze southern SA and southwest VIC with the low chance of a thundery shower under it.
Thunderstorm Forecast Monday
Thunderstorms are forecast to emerge over the southeast with a cold front moving through Victoria and eastern Tasmania. Some of the storms could be gusty with moderate rainfall. Thunderstorms over the tropics forecast to contract further east but may increase in coverage if a tropical low forms near QLD. So this forecast is variable for northern areas.
Thunderstorm Forecast Tuesday
Thunderstorms will be a low risk under a cloud band over the southeast and mainly on the periphery of the cloud band. Thunderstorms will continue over parts of the northern tropics but more likely over Cape York.
Thunderstorm Forecast Wednesday
Thunderstorms should contract through NSW and eastern VIC with the departing rain band. Isolated showers and thunderstorms possible over the western interior near a weak trough and the showers and storms should contract east over Cape York during Wednesday where the higher chance of convective weather remains.
Thunderstorm Forecast Thursday
Cool stable air for much of the nation is expected with only a few very isolated thundery showers possible over the far north. The unsettled weather returns to inland areas of the south and east from Friday into the long weekend.
MEDIUM TERM - April 24th - May 1st 2022
Moisture looks to spread throughout the nation's interior with a deeper easterly flow forming via the easterly winds a top of a high that is sitting in the Tasman Sea. That will assist in drawing moisture into the eastern states and possibly into another trough that will be sitting over the region leading to widespread rainfall and the Autumn Break. Another moisture surge over northern Australia with a tropical wave passing north of the nation is possible with increased humidity and late season falls for the far north. This moisture too could be drawn south or southeast into the nation lifting rainfall chances. Another wave of low pressure passing through from the south of WA could surge northwards and bring a colder drier airmass towards Australia, which may help to promote another rain band forming in Southern Australia at the end of the period.
The anomalies are shifting above average as we move through the period with many areas now leaning towards a wetter bias for the period, thanks to the secondary system on the charts we can see over ANZAC Day and another system lurking out there in early May. Now in pinning down who gets what relating to rainfall totals, that is not possible, but you can clearly see the areas identified as being wetter than normal. And a good chance for many of you.
Becoming cooler as more rainfall and cloud cover takes over the nation with the warmer than normal weather of this week moving further east and north across the country with a colder shift for the southwest, south and eastern inland quite possible as we move into May.
DATA - Next video is due out tomorrow when we are all back from our holiday routine. Have a great Easter Sunday!
12Z Euro Surface Pressure Pattern and Rainfall Distribution - Next 10 Days
A fairly dynamic pattern with widespread rainfall developing today over the southeast after a very warm to hot Easter Sunday. Some moderate to locally heavy falls are possible in VIC with this system, especially for central and eastern areas. The rain moves into southern SNW and the ACT with good rainfall also possible now, we get a better look at the system in real time so numbers should firm up for many Ag Areas. Eastern and southern SA should get light falls for now, but a few falls over 10mm are possible in the far east. The rainfall then clears mid week. Tropical weather remains active but the heaviest of the weather is moving into QLD this week with late season above average rainfall possible. In the west, mostly fine for now but cloudy skies over outback areas could lead to widespread patchy falls. A better rainfall event seems to be setting up in the medium term which I speak about below with a front moving eastwards from WA and slamming into moisture being drawn in from the tropics through SA. This could lead to a fairly robust Autumn Break developing towards the end of the month. This system could also bring the end of the above average temperatures for a while as well and help to clear the tropics out too.
12z Euro Precipitable Water Anomalies - Next 10 Days
Noting the moisture plume coming through from today over southern and southeast areas ahead of a front and part of that moisture hanging back over WA also causing patchy rain and cloud. The tropics remaining very much above average in terms of humidity. The next pulse of tropical moisture over QLD is the moisture to watch with that feeding south or southwest into the centre of the country leading to cloud developing and with a trough in the region widespread rainfall should develop. Another impulse of moisture spreading down the spine of a cold front into WA will also bring up rainfall chances later in the period. Moisture over the east of QLD will lead to enhanced rainfall.
12z Euro Rainfall Accumulation - Next 10 days
Latest Euro has two events on the board for the inland, the initial system starting today bringing a reasonable drop that many farmers would be happy with over VIC and NSW into the ACT, that clears east from late Tuesday. Onshore winds brings showers to the east coast in the wake of the feature with a high ridging through the Bight. But another deeper moisture plume is set to emerge from the tropical north and be drawn southwest into a new system developing this weekend over SA and QLD. This system allows all the moisture to be lifted into rain and storms. Some heavy falls would be possible under current guidance but don't get too excited just yet. We have complexity with a front emerging over WA through this period and that could either make the system boom or bust this system as well. So lots to watch. Generally, most Ag areas from WA through SA into VIC, NSW and some parts of QLD will see reasonable rainfall chances in this period but numbers will vary.
12z GFS Rainfall Accumulation - Next 10 days
The latest GFS sees reasonable falls over the southeast and east of the country with this initial cloud band that is emerging today. There is a lot of moisture spreading throughout QLD and into the central interior leading to scattered falls for inland areas and widespread rainfall for the FNQ and Cape York regions. But the GFS does not quite verify the secondary trough as sharply in the coming 10 days and like the CMC delays it to the end of the month. But widespread rainfall emerges nationally outside of this period. I think that is too slow.
12z CMC Rainfall Accumulation - Next 10 days
The latest CMC supports a reasonable rainfall event developing from tonight through the southeast with the band of rain really kicking into gear over western VIC and into southern NSW through the coming days. Showers develop for the east coast in onshore winds with a high moving into the Tasman Sea during the week leading to light falls generally. Another upper trough develops through Central Australia and this has moisture being pulled into the system from the northwest and north leading to widespread falls emerging through the interior, then moving south and southeast through towards the end of the month, but the CMC has this system further delayed and north and west. Not a bad thing, but would mean a longer wait in the Autumn Break arriving.
12z Euro Rainfall Accumulation - Next 15 days
Moisture streams south from the tropics through QLD and into a developing upper trough over SA where rain and storms develop. This will be in advance of a cold front and trough moving through the Bight and lifting all this moisture into a large rainfall event bringing the Autumn break for SA and VIC into western and southern NSW. The rainfall over the northern tropics, though looking lighter is above average. The rainfall through WA and eastern portions of QLD may be patchier.
12z GFS Rainfall Accumulation - Next 16 days
Moisture streams into the southern and central inland ahead of a cold front, with this tropical moisture combining with moisture from the Indian Ocean and leading to extensive rainfall for eastern WA, through SA, VIC, NSW and the ACT. Patchier falls for now getting into northern NSW and southern QLD. Heavy late season rainfall is possible into the medium term, but mainly over QLD. Drier for the northwest of WA.
More coming up on Monday or if anything else breaks weather wise that needs to be discussed. Have a great Sunday!