The trough that has brought extensive severe weather over the past week in SA then into VIC overnight and western parts of NSW overnight into this morning, is slowly moving eastwards and is triggering severe thunderstorms once again over the west and southwest of the NSW this evening.

A very humid airmass is in place and remaining in force for the coming 5 days or so with the trough nearby, more of the same is expected with showers and storms to feature for many of you, the hit and miss storm lotto continues, but where it rains, boy it will pound down.

There is not much variation in the weather until we see a stronger trough moving through the southeast and east of the nation and a southerly flow moving into the region. That may allow the southerly flow to whip up more instability over the east coast, with a trough lingering, showers may increase while the inland improves.

So the weather over the short term, wettest and unsettled on and west of the divide. From mid next week, the wettest and more active weather on and east of the divide with the trough in the east.

Severe weather potential is featuring on many days in the short term.

Lets take a look


Rainfall Next 10 Days

Rainfall continues to be of uneven distribution throughout the coming few days, but some locations as we saw over the southwest last night, will be smashed. There will be local daily falls of 70mm over a broad area, but surrounded by light to moderate rainfall totals. The rain and humidity will start to lift out of the western areas of the state come early next week as the trough over the southeast moves north and east and with some luck, mid next week we will see more settled and drier air move over the southern and central inland with cooler air and clearer skies. On and east of the divide, dry for a while for the most part and very humid but it won't be until your southerly change arrives next week that rainfall returns for the region and the chance of heavy rainfall developing with the trough is quite decent at the moment so will take a better look at that over the weekend. For now the short term is dictated by the storms and the patchy rainfall, but where the storms form, you will certainly know about it.

Heavy rainfall in the coming days over the southeast of NSW could lead to areas of minor flooding in the coming days.

Thunderstorm Forecast Friday

Thunderstorms are expected to refire through the late morning and into the afternoon and evening with some of the storms likely severe. Flash flooding is the main concern with intense rainfall likely to be featuring. Some storms could deliver 50-100mm over some areas and no one can tell you where these severe cells will form ahead of time, but I can give you the best guide in the chart below. Southern areas and over the western side of the state up to about White Cliffs is the region where you will find the nasty storm risk. Garden variety storms, still with a heavy rainfall risk, will exist throughout the remainder, but the east coast looks stable for now. Be weather aware!!

Flash Flood Risk Friday - NEW SOUTH WALES

A significant risk through Friday. Rainfall rates could exceed 300mm/hr in some locations, that is based off what has been observed in some areas of VIC and NSW overnight, that could be repeated in the same areas on Friday, mainly afternoon and evening. Dangerous flash flooding is possible in the southwest, southern and along the western border with thunderstorms.

DATA - Refer to the short and medium term break down in the video with further details for your part of the world. Medium term off the GFS is very low confidence

00Z GFS - Surface Pressure and Rainfall Distribution - Next 16 Days

As per the video - not much change in the short term with the monsoon and tropical lows over the north driving the heavy rainfall. Trough slowly moving east through the southeast finally bringing the severe weather risks into the eastern inland this weekend, and clearing to southeast of the very unstable weather. The tropical low over the northwest is something to watch as well which may bring heavy flooding rainfall over the weekend. It is the medium term that offers no help to figuring out the rainfall potential nationally. The guidance is very poor and remains low confidence. More in the models and rainfall analysis this evening.

00Z GFS - Precipitable Water Values - Next 16 Days

The very deep moisture profile is still with us for a number of days over much of the south but you will find that retreats slowly through the outlook period back to northern and eastern Australia as new high pressure comes in. Once again the signals from the models are for the monsoon to remain in place over northern Australia. What the GFS does with that information is to create tropical lows, which for the most part are bogus, but what that tells me is that the tropical weather is expected to be dominated by the monsoon trough. Where that moisture goes remains to be seen. So stay tuned.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to video for further information

00Z CMC- Rainfall Accumulation - Next 10 Days

Refer to video for further information

00Z GFS - Rainfall Accumulation - Next 16 Days

Refer to video for further information

A closer look in - hit and miss storms will result in uneven distribution of rainfall. The southeast will turn drier but the east coast will turn wetter next week.

A detailed look at all things rainfall and the model data tonight, people getting more itchy about the seeding season ahead, it will be here before you know it!

71 views0 comments