A windy, stormy cold front will move across the south-eastern states over the next couple of days, with the widespread risk of damaging winds and severe thunderstorms. Let’s take a look at how this story will play out.

Starting with today, we’re seeing a low-pressure system and cold front moving across South Australia. Areas of rain, showers and thunderstorms are pushing from South Australia into western Victoria today. Later today, we’re going to see this low-pressure system slipping to the south-east of South Australia and moving into western Bass Strait. At this time, the low is going to deepen, becoming more intense, drawing in more power and stronger winds around that centre.

Through the day tomorrow, our low will continue to slip to the south-east, starting to move quite quickly. That means our strong winds, rain and thunderstorms will push across those eastern parts of Victoria and into New South Wales. Later tomorrow night, we’re going to see this system moving offshore, taking those strong winds and wet weather with it, leaving us with much more settled conditions from late tomorrow into Thursday.

Now, the winds really are the key hazard with this weather system, so let’s take a closer look at those now. We’re looking at the winds above the surface, around 1.5 km above the ground, to get a sense of where those strongest winds are moving in the atmosphere and how high the top wind gusts might be that could reach the ground. As you can see, we could see some breezy conditions through southern parts of South Australia as this system moves through today. But it will be late tonight into early tomorrow morning, when we see this low-pressure system really starting to deepen, that we’ll start to see some of those dangerously strong winds developing for south-east South Australia and Victoria.

As the low-pressure system moves east through tomorrow, the strong winds will also move east, extending through Victoria and New South Wales with the system’s movement. Again, all of these strong winds will start to ease back later in the day as the system moves away, with much more moderate winds expected for Thursday.

Now ahead of this wind risk, we have issued Severe Weather Warnings for damaging winds across those three states, so covering south-east South Australia, pretty much all of Victoria, and parts of south-east and eastern New South Wales, including the Blue Mountains to the west of Sydney and the Illawarra Shoalhaven area. Very windy conditions are expected throughout the south-east as this cold front moves through, but in these warning areas we could see damaging wind gusts reaching 90 to 110 km/h. Winds of this strength are definitely strong enough to bring down trees or tree limbs, potentially causing damage to property, cars or power lines, and also producing very dangerous driving conditions.

Again, that peak of the winds will ramp up in the western parts of the warning area first, pushing eastwards through the day with the system, easing back in those western areas later on Wednesday. The strongest winds associated with this system will occur close to the low-pressure system itself. That means coastal areas between Cape Otway in Victoria and around Robe in South Australia. This stretch of coast may see locally destructive wind gusts through Wednesday morning into the early part of Wednesday afternoon—that means wind gusts up to 120 or 130 km/h.

We may also see some damaging wind gusts outside of these warning areas, driven by thunderstorms. Let’s take a look at our thunderstorm forecast for the next two days. Today, our focus is really through South Australia. We may see storms pushing into western Victoria and parts of eastern New South Wales too, but these are likely to be non-severe and fairly isolated. In the western parts of South Australia, pushing down to the Eyre Peninsula, however, we have this yellow area indicating that severe thunderstorms are possible through those parts today. Any severe storms could bring damaging wind gusts through the course of today.

As we move into tomorrow and our cold front moves east, we’re going to see our risk of storms also moving east. Storms are possible throughout the south-east, including down to the northern parts of Tasmania, with severe storms possible across a much broader area as well, including the entire state of Victoria, south-eastern parts of South Australia, and much of New South Wales too. Even southern inland parts of Queensland may see some severe storms tomorrow. Again, any severe storms bring the risk of damaging wind gusts through the day tomorrow. It is a good idea to keep an eye on the radar and the Bureau’s Warnings page so you can stay on top of those storms as they move through.

Finally, let’s take a look at our rainfall over the next few days. Our rainfall totals out to midday on Friday show us that moderate falls are possible across those southern and south-eastern parts of South Australia, parts of Victoria and throughout Tasmania. The highest accumulations of 50 mm or more are most likely to be driven by thunderstorms, more likely across parts of Tasmania. So it’s not so much an incredibly wet system, this one, as one that’s likely to bring that risk of damaging winds and severe thunderstorms.

As this system approaches then moves through, it’s essential to stay on top of the latest forecasts and warnings via the Bureau’s website, the BOM Weather app, and via our social media. Stay safe, and we’ll catch you next time.