The active pattern continues with one system on by to the east and the next one already developing over the Bight this evening, the trough running into moisture left over from the first system that has brought reasonable rainfall today to parts of northern and central NSW and the northeast.
Tomorrow will start out fairly calm with a good supply of sunshine, high pressure passing through from the west to the east. This will lead to a warmer day and many areas back to near seasonal temperatures.
Afternoon we will start to see cloud developing and after 4pm, scattered showers and thunderstorms will begin to break out over western districts, particularly over the southern inland bordering VIC. Some of those could be severe with damaging winds and heavy rainfall. Large hail is not a high risk but it is possible.
Thursday and Friday could be rough across the state. The only mitigating factor would be cloud cover and timing of the trough moving through your region overnight rather than during the peak of daytime heating. So those areas will be narrowed down in the coming 24-36hrs.
Once we see how the trough performs tomorrow afternoon and where the low pressure system moves through SA, we can then be more precise with risks.
Lets take a look
Rainfall for the next 10 days
Rain clearing from the northeast and central inland tonight as the low and trough lift out. A new trough arrives tomorrow bringing scattered to numerous showers and thunderstorms during the afternoon and evening. This band of showers and storms moves east through southern and southeast NSW tomorrow night reaching the ACT during the evening and points north and south of there along the Southern Tablelands. Widespread showers and thunderstorms are expected for much of eastern NSW during Thursday with severe storms likely. Then showers increasing in the colder air over the southern and western inland with a low approaching from the west. Storms could be gusty with small hail and moderate falls. Another round of strong storms could pass through the northeast on Friday with the trough lifting out. The showery air over the southern inland continues with local hail and thunder about. That will ease by Saturday and the weather dry by Sunday. The weather next week flips, warm to hot conditions and drying out ahead of a thundery change later in the period.
A closer look at where rainfall is expected to be heaviest.
Thunderstorm Forecast Wednesday
Thunderstorms are likely to develop along the axis of a trough moving into moist air. Dynamics moving out of the west will catch up to the trough and promote the development of thunderstorms, with storms turning severe through parts of southern NSW and most of western and central VIC. Heavy rainfall leading to flash flooding with thunderstorms training over the same area along with damaging winds the main risks. Large hail may feature on the northern end of the band in southern NSW. The risk moves east during the evening, but storms may weaken somewhat.
Flash Flood Risk Wednesday
Flash flooding is a moderate risk with thunderstorms during Wednesday afternoon and evening. Rainfall rates of 20-40mm/hr possible with the thunderstorm bands training over the same area, but isolated falls of 50mm cannot be ruled out. The rainfall intensity eases during the evening.
Damaging Winds Risk Wednesday
Damaging winds a moderate chance with thunderstorms with the most likely area to be on the leading edge of the band of precipitation. Winds may reach 100km/h in some spots but the damaging winds risk increases Thursday.
Large Hail Risk Wednesday
Large hail is a low chance during Wednesday afternoon with the main area on the northern flank of the band moving through southeast Australia. The large hail risk increases during Thursday and Friday over NSW and into QLD.
Farmers and Graziers - Thursday through Saturday.
A nasty low is expected to run across SA on Thursday bringing well below average temperatures, gales and heavy showers with hail. The wind chill will be running very high. That cold airmass descends over VIC and into southern and western NSW during Friday and continues into Saturday with a colder southwest to southerly flow as the low develops in Bass Strait. Conditions ease from the west during Saturday clearing SA during the morning, NSW by afternoon and VIC by Sunday. The risk to stock exposed to these conditions is high.
00z Euro Surface Pressure Pattern and Rainfall Distribution - Next 10 Days
The main feature is most certainly the low pressure system passing through the south and southeast this week with a leading trough leading to severe and even violent weather potential Thursday and Friday for NSW and QLD. The peak of the weather in terms of storms is Thursday. Rain heavy at times over VIC could lead to areas of flooding over southern areas, mainly east of Melbourne and West Gippsland. South Australia likely to see a decent amount of showery weather Thursday with gales as the low passes over. The west is warm and dry and the north is under the influence of deep moisture with scattered showers and afternoon thunderstorms. From Sunday the weather over the nation turns quiet with all low pressure moving away and upper high pressure taking over. The west is where the action will be next week with a band of rain and strong winds along an unusual strong cold front and trough passing by. That system will help to lift temperatures well above average across the south and east.
00z Euro Precipitable Water Anomalies - Next 10 Days
No real change from this morning with a deep moisture supply lifting off the east coast but some being left behind ahead the next system coming into SA helping to produce widespread showers and thunderstorms. The weather over SA and VIC turning colder and the airmass drier with a southwest to southerly flow wrapping into the low bringing in cold air from the Southern Ocean. The weather over in the west warm and dry before the next large moisture infeed from the Indian Ocean which is expected to bring above average rainfall. The northern tropics humid and trending even more humid next week with an upper high suppressing rainfall for a period.
00z Euro Rainfall Accumulation - Next 10 days
Refer to video for more information on rainfall.
A closer look in.
00z GFS Rainfall Accumulation - Next 10 days
Refer to video for more details on rainfall
I will have a full wrap on the models and rainfall tonight after 9pm EDT. It is a significant risk of severe weather over vulnerable crops during Thursday. Remain weather aware in the east. But pay attention into the WA weather because that warmth is heading east next week.