The severe weather has delivered exactly as forecast in parts of the southeast yesterday and overnight with some locations in Central VIC picking 200mm of rainfall from stationary thunderstorms. The concerning issue for the coming days is that more of these spot falls where some locations get 2-3 months worth of rainfall in a sitting continues. So if you are living in central or eastern VIC, through southern and central NSW, the ACT, southeast NSW and parts of the NSW coast north of Taree, expect some further flash flooding, some of the impacts also being felt as riverine flooding in some locations.

This weather pattern will remain in place until the weekend as the trough weakens and the surface component lifts out over NSW into southern QLD.

The weather is expected to turn more unsettled over the tropics over the weekend and into next week with a deepening heat low initially over the inland of the NT and a developing tropical low over Cape York. The system over Cape York may develop into a cyclone and head west over the north of the nation, this dragging in a northwest monsoon into the feature as it moves across the north, turning the tap on and cooling things down once again for northern Australia.

The problem with this, more rainfall and heavy rainfall at that is a chance of southern and eastern parts of the nation, depending on the track of the tropical feature, this may include the western interior of the nation as well, where the wet is yet to really get underway. It does from about now through April with tropical cyclone season peaking in the early Autumn.

The weather for SA and southern WA remains unchanged until then, with warm weather for SA and hot to very hot weather for WA lifting fire dangers.

The problematic weather of high impact remains over the east with the flood risk remaining high.

Lets take a look


Rainfall Next 10 Days

Heavy rainfall overnight has resulted in some areas clearing 100mm in parts of VIC and NSW already with scattered falls towards 50mm with further heavy rainfall on the go. So be aware that this weather is likely to remain unchanged for the coming 2 days for the southeast with a humid airmass and a series of troughs being fed by unstable easterly winds. Along the east coast, the remnants of Seth will bring widespread showers, some heavy with the chance of thunder, this lasting through to next week. Over the north, the wild card on the board is the developing tropical low within a trough deepening north of QLD or the NT. This will bring up rainfall over northern Australia next week. The further west this system runs across the nation, the wetter the weather will be as the monsoon flow is then drawn in over the nation via upper northwest winds. For now the south and southwest of the nation remains dry, with interior parts seeing the usual hit and miss elevated gusty storms.

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. Dangerous flash flooding with rainfall rates of 70mm/hr plus are possible in the purple zone. 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.

Thunderstorm Forecast Saturday

Thunderstorms will slowly contract out of the southeast and move into Central NSW and points north and east near to the east of a trough that will once again pull up stumps somewhere over northern NSW Sunday. The storm focus continues with routine expectations over northern Australia for a monsoonal break period.

Tropical Depression Forecast - Next Fortnight.

Just because it is shaded in over northern Australia, do not think that the impacts of any tropical weather will remain up north. We are already feeling the impacts of the short lived monsoon from Christmas now entrenched over the southeast and east of the nation for the next few days. So this area is critical to seeing how much more rainfall is to come through the next 2-4 weeks and then February which is still looking like the wettest month for Summer.

DATA - Refer to the video for more guidance on the data sets below

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

The deep trough in the east combining with elevated moisture levels left over from onshore winds, the monsoonal burst up north and the remains of Seth all mixing together to create this volatile weather as expected. This is set to continue. The northern and western parts of the nation experiencing near seasonal weather with hot and dry weather for much of WA and the routine showers and storms the NT and parts of north QLD. SA, remaining dry and settled at this time. The east is where you will find the continuation of heavy rainfall and thunderstorms with localised flooding. The weather easing over the weekend. Next week, all eyes on the trough reorganising over the east and pushing west through the eastern inland, that will be as a tropical feature emerges over QLD and also passes west through the NT. This system will bring up rainfall chances for the north and the chance of dragging in the monsoon. This system on current trends could bring a flood event to interior parts of the nation and follow up falls for the east where heavy rainfall is ongoing today through Saturday.

12z Euro - Precipitable Water Values - Next 10 Days

The deep moisture profile remains in place, hence the proficient rainfall rates we have observed in recent days. The weather is expected to remain unchanged through the coming 2-3 days for the southeast and east before the humidity is shifted into QLD and northern NSW. Though it is short lived as the high recentres over the Tasman, it will take the trough over the east back to the west, with deeper moisture passing through NSW into eastern SA and back over VIC with widespread rainfall chances. The west and far south remains in drier air, particularly west of the trough in the east, but the moisture profile will increase nationally next week as the tropical weather turns more active, that westward moving system is one to watch from QLD through the NT and as it moves further south, could be bringing up the chances of a flood for interior parts up north as well.

12z Euro - Rainfall Accumulation - Next 10 Days

More information in the video at the top of the page.

12z CMC - Rainfall Accumulation - Next 10 Days

More information in the video at the top of the page.

12z GFS - Rainfall Accumulation - Next 10 Days

More information in the video at the top of the page.

12z Euro - Rainfall Accumulation - Next 15 Days

More information in the video at the top of the page.

12z GFS - Rainfall Accumulation - Next 16 Days

More information in the video at the top of the page.

More to come today - stay weather aware in the east and southeast with flash flooding a major concern. We have had a week to prepare for this weather and now it is here. Best of luck.

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