MODELS AND RAINFALL - THE WEATHER SET TO REMAIN WET FOR A WHILE AND COMING TO DRY WA.

The weather is looking more typical now of La Nina summer, and we have not felt the impacts of the La Nina peaking just yet, that is a few weeks away I suspect. So for now we are feeling the build up to the peak before conditions wane in March and April.


For now the short and medium term is offering a very wet spell for northern and eastern Australia. However the rainfall numbers for central parts of the nation, especially the NT an into northern WA and perhaps western QLD, are well above average and may lead to further flooding issues for Outback areas.


Those who love the tropical weather, this forecast is one you will enjoy!!!


SHORT TERM

Once again the short term dominated by the monsoon up north, a merged trough over central areas of the nation increasing the flood risk for inland parts of Australia. Another trough snaking into the southeast and eastern inland through the coming days may produce heavy rainfall and flash flooding risks for many locations in VIC and NSW as well, possibly stretching into the ACT. The humid weather may begin to move out from about 7 days from now clearing conditions over southern Australia. The driest parts of the nation are southwest WA and TAS.


UKMET - Rainfall Next 7 Days - LOW CHANCE FOR THE SOUTH - HIGH CHANCE NORTH.

Moisture is expected to be widespread and deep across northern Australia. Indications are that the monsoon will likely strengthen through this period leading to heavier rainfall across northern Australia. As the trough moves northwards, the weather may turn heavy over interior parts of central Australia and extend into northwest Australia. The moisture over the east and southeast will continue to be uneven. Otherwise the model suggests heavy rainfall may reach western SA but this is not overly supportive.

ICON - Rainfall Next 8 Days - LOW CHANCE.

This model suggests the monsoon will stay over the northern parts of the NT and not descend south. So that means rainfall is lighter. Tropical low pops off the WA coast and leads to heavy rainfall moving off the west coast and not south through WA. Otherwise uneven distribution of rainfall continues for many areas in a humid airmass.

MEDIUM TERM

The medium term is expected to remain very wet over northern and eastern areas of the nation with a very wet monsoonal flow continuing for the north. The trough may begin to contract northwards through this period, increasing the risk of cyclone activity over the north. The troughs over the east may get stuck over QLD and NSW with coastal areas possibly seeing a return to heavy rainfall in the onshore flow. The unsettled weather over the interior of VIC, NSW, SA, QLD and the NT may continue. The west, could be wet now with the weather turning more in line with the development of the wet season. The tropical low that comes down in the short term may shift the upper air pattern and therefore open the door for rainfall to spread across the west and indeed the nation.


CMC - Rainfall Next 10 Days - MODERATE CHANCE.

Like the ICON, keeps the monsoon further north and pops the tropical low off the WA coast. Heavy rainfall will wrap over northern Australia leading to a flood risk. Deep moisture stuck over central parts of the nation will lead to a flood risk. Showers increasing over the southeast and east next week with a slow moving trough. Drier air moving into SA will clear the rainfall northwards.

EURO - Rainfall Next 10 Days - HIGH CHANCE

The Euro has performed well so far and I am leaning against this for the short and medium term. Note the monsoon trough coming deep south into the NT through central WA and extending northeast into Cape York with a tropical low attached. Once that low dislodges from the monsoon trough, then the trough will snap north and form more tropical lows as it moves north. The southeast wet with showers and thunderstorms. The Euro in the longer term has heavier rainfall for the east coast and drier weather for southern SA and much of VIC.

ACCESS - Rainfall Next 10 Days - MODERATE CHANCE

The latest ACCESS is placing the rainfall in line with the Euro and taking it into WA and the NT more than through SA. Note the east coast getting wetter with a trough combining with the easterly wind component into the medium term. Will have to watch that developing weather story in the medium term. Tropics remaining active.

KMA - Rainfall Next 12 Days - LOW CHANCE

The KMA now falling into line with other global models and taking the tropical low into WA and then diving it south, still has it going too far east but the idea has shifted. I think the moisture will run across the nation at some point but not to the east until the end of the first week of February. The east coast is too dry.


GFS - Rainfall Next 16 Days - LOW CHANCE

The GFS keeps the rainfall over much of the NT with heavy falls leading to flooding. That will continue over the northwest of QLD as well and through the tropical north with the monsoon so flood risks are running high through the outlook. The model also wants to take the tropical low through interior WA with heavy rainfall spreading south, but this idea is not well supported. The GFS also suggests heavy rainfall may develop for eastern QLD and the NSW coasts in the medium term with a flood risk but this is a long way out. Otherwise uneven distribution of rainfall expected in most areas.

ENSEMBLE DATA

The ensemble data somewhat in good agreement but the rainfall will be uneven in distribution, thanks to the dominance of a soupy airmass and thunderstorms in the mix. So that will continue so do not be surprised if you get more or less than what is shown here. Overall, the trend is looking unsettled for many areas. All models carry a moderate chance.


GFS - Rainfall Next 16 Days (median of 35 members) - MODERATE CHANCE

CMC - Rainfall Next 15 Days (median of 30 members) MODERATE CHANCE

EURO - Rainfall Next 15 Days (median of 51 members)

LONG TERM

Wet signal continues and you catch up more on that in the update pinned at the top of the blog page.


Euro - Rainfall Next 6 Weeks - HIGH CHANCE

The wet signal is very strong despite the low confidence in the deterministic data.

More coming up at some stage on Australia Day. It is a public holiday and the next update will arrive some stage on Wednesday morning.


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