The west and south, same old song and dance, dry, benign and stable weather with high pressure close by keeping things settled and clear with increasing temperatures for WA and warmer weather for interior parts of SA.

The east and southeast is where it is at today with a significant coupling of a surface and upper level trough ramming into the very moist air left over by the ghost of Seth in onshore winds. This mix will see very active weather develop with further severe weather potential today through Saturday.

Flooding is a major risk from this event with the damaging winds and large hail a low risk so focus on the rainfall and flooding potential is key here.

For the north, the routine showers and storms continue, very hot muggy weather as well, the build up to the next wave of monsoonal weather is now on and we should see that emerge in the coming week on the forecast charts. Models having a hard time placing it and timing that through the north and the subsequent impacts down the line for the rest of the nation.

That would pose a risk for further significant rainfall over areas copping it this week so another feature to watch.

Lets take a look at the short term and a wrap of the medium term.


Rainfall Next 10 Days

The rainfall distribution is excessive in parts but sadly the confidence is low across the board as mentioned in the video. There are multiple very plausible solutions that offer a few places an absolute deluge and one or two member sets showing some catastrophic flood potential for parts of the southeast and north of the nation. For now, I am playing a straight bat with the consistency key to the forecast. The Euro is broadly more favourable in terms of the placement and distribution of rainfall, but it struggles on the convective set up on rainfall events, so I am applying the CMC/GFS rainfall for the southeast and along the east coast. There will be places shaded in over the southeast that are expecting heavy falls, that won't get them, it is the nature of the beast with these storm set ups but be aware and prepared none the less and hopefully you come out unscathed. For the west inland storms continue in the high heat and increasing moisture profile, but storms scattered and relatively moderate if anything falls. For the north, the placement of the tropical system is key, but I am aligning with the Euro based off consistency from this model and looking at the broader data sets this morning, a tropical feature running west across Cape York through the NT then southwards into the mid latitude northwesters bringing increasing rainfall and flooding chances to the Outback and cattle country.

Thunderstorm Forecast Wednesday

Showers and thunderstorms have become more widespread this morning over the southeast with storms tending severe with heavy rainfall leading to flash flooding the main concern. The storm coverage over the north and northwest also on the increase with storms tending severe, gusty damaging straight line winds are possible. Thunderstorms may also produce heavy rainfall.

Thunderstorm Forecast Thursday

The trough over the east amplifies in response to the approach of an upper feature from SA and the absorption of Seth in the east so widespread showers and thunderstorms with heavy rainfall leading to flash flooding the main concern. Thunderstorms extend through inland QLD, though more scattered, may be gusty and heavy also. For the northern tropics, the thunderstorms will likely trend more gusty once again during the afternoon and evening with dry high based storms extending southwest from the tropics into the Pilbara.

Thunderstorm Forecast Friday

Thunderstorms continue for the same areas into Friday with severe weather continuing over the east and southeast with the trough stationary. Heavy rainfall leading to flash flooding and damaging winds are the main issues. The highest risk once again over inland areas of NSW and VIC. The storm coverage over the north remaining unchanged with a deep trough developing over the northern states. The trough will snake back into WA with a chance of gusty storms but mainly light rainfall totals for now through to the Pilbara and Gascoyne.

DATA - Refer to the video to see the other models and the madness into the medium term.

12Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

I am siding more with this solution and the only reason is consistency. The short term is very stormy, wet with potential flood risks for the southeast with severe storms. Heavier rainfall developing with the emergence of ex tropical cyclone Seth moving onto the coast of SE QLD and NE NSW. The tropics active with widespread showers and thunderstorms continuing. Elsewhere, rinse and repeat weather for SA with mild to warm weather for the coastal areas and hot inland, sunny skies. The heat is on for WA with easterly winds, bringing that same wet weather to the east, drying out and warming up as it heads across the continent.

12Z Euro - Precipitable Water Values - Next 10 Days

No real change to the moisture distribution with the heaviest of that moisture profile staying over the east and north. Interestingly, some parts of the east coast are likely to see higher moisture levels than parts of the northern tropics at times this week. That will change by the time we get to next week with the monsoonal weather approaching from the north and the air modifying a tad over the east, but still remaining soupy and unsettled over the east. Drier air over the west or the next week, but the confidence is not especially high with models diverging as far apart from each other as possible.

12Z Euro - Rainfall Accumulation - Next 10 Days

Refer to the video for more details

12Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more details

12Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more details

12Z Euro - Rainfall Accumulation - Next 15 Days

Refer to the video for more details.

12Z GFS - Rainfall Accumulation - Next 16 Days

Refer to the video for more details.

A more detailed look at the severe weather threat coming up this morning for the east and the latest on the tropical waves over the north of the nation and what impacts that may have in the medium term, as you can see the guidance is pretty rubbish right now but the impacts could be high stakes for many out in the bush.