Significant frontal activity is expected this week with a front Tuesday to bring widespread showers, hail and thunder with snowfalls coming back down to 600m during the day for southern areas.
A low pressure system is expected to move from WA into SA with light falls of rainfall from that weakening system anticipated to reach the northwest of VIC during Thursday. That is ahead of a strong cold front due in the west of VIC Thursday night or Friday.
That front may bring gale force winds ahead of it, with it and then behind it, a widespread damaging wind event is not impossible later this week. The rainfall expected with that system is also likely to be light to moderate for most. Some heavy falls could develop along the northern slopes of the GDR ahead of the front itself on Friday before the winds shift westerly and then southwesterly taking the showers onto the ranges and over the southern plains.
The system later in the week could be a severe weather event with damaging winds the big threat. The pressure gradient on some of the modelling lends itself to being a high impact event so I will be watching for trends. Right now the risk is MODERATE.
More frontal weather and rainfall does exist beyond the coming weekend into next week.
12Z GFS Surface Pressure Pattern for the coming 16 days
The weather is classic winter for VIC, the fast flow pattern with a front every 36-48hrs with persisting westerly winds. That sees the showery weather for most days over southern and mountain areas. The stronger fronts brings local hail and thunder tomorrow with snowfalls down to 600m. That repeats again during later this week with some higher rates of rainfall and a chance of damaging winds for large areas of the state thanks to a deep low over TAS. That system needs watching. Then more frontal weather to sail through over the weekend into early next week with the westerly winds continuing, the north may dry out. For those north of the divide, your rainfall on this model would be later tomorrow, Thursday with weakening low which may surprise and then squally showers over the weekend.
12z GFS Rainfall for the coming 10 days
Rainfall reflected in the westerly wind belt means the same areas that were wet last week, remain wet this week. Rain increasing from a low pressure system over SA may bring some OK falls to the Mallee - maybe 5-10mm if it behaves. Then more widespread showers developing later this week which may bring a further 5-15mm for the northern areas, 10-25mm for the south with those gales. More rainfall next week but for coastal areas as the fronts just back off a little further south as high digs in over the centre of the nation.
12z Euro Surface Pressure Pattern for the coming 10 days
The Euro, very similar in it's run to GFS with a westerly wind belt and embedded cold fronts moving through. The low is certainly the wild card system with a deep layer of moisture coming for northern VIC mid to late week before it becomes absorbed into the westerly flow and long wave rearing up from the south. The weather supports wet phase over those areas exposed to a westerly wind regime. Keep watching the frontal weather next week too, I will be having a closer look at that later today with the Indian Ocean watch this evening.
12z Euro Rainfall for the coming 10 days
Rainfall very similar in spread to the GFS which means that the forecast spread of rainfall is rather simple, but who gets what will come down to two things, one being where the mid week low pressure system goes. The other will be the bearing of the westerly winds with the fronts, more northwesterly in nature and the Alpine areas of VIC and northern slopes of the state does better, more southwesterly and the Alpine areas do well but the better falls develop for West Gippsland and East Central areas as well as the Central Ranges between Yandoit and Macedon.
Rainfall for the next 10 days.
Rainfall has been increased for Victoria thanks to the westerly wind belt and a weakening low pressure system over the coming 10 days laden with moisture, bringing widespread falls off and on during this period. Clearly the most active weather is expected during tomorrow with a cold front, the weakening low for northern VIC into southern NSW, then the widespread rainfall developing during Friday with a powerful front which again may bring a damaging winds risk as well, which I will keep watch on and have a chart out for tomorrow. Snow fans, up to 50-70cm of snowfalls possible during this period, possibly 1m if the weekend system peaks further north.
More weather details to come throughout the day.