We’ve got some showers moving in today, courtesy of a southerly change, a surface trough and some increasingly cold air up high. The forecast radar from this arvo through tomorrow afternoon looks like this:
You can see the showers move in from the coast and then stick around as they hit the Coffs / Dorrigo range right through the night and into tomorrow. There is the potential for some reasonable totals over the next 36 hours, adding onto what we’ve seen over the last few weeks.
The change in the weather has been brought about by the rise in the Antarctic Oscillation. You can see it sitting in the positive from Mid June through Mid July, then it heads into the negative, particularly from mid August through September…coinciding with the much drier fire weather we’ve been experiencing. Current forecasts take it back into the negative through October / November but we’re yet to see that happen.
What we are seeing are the forecasts heading into the negative, but then sliding back towards neutral again. Here’s the latest animation that shows the Oscillation right through the depths of the atmopshere:
You can see it sitting in the deep negatives up high, but struggling to transfer to the surface. This is the one to watch over the next couple of months. My best guess would be for it to finally make it down to the surface, likely giving us some hot and dry spells with an increased risk of fires once again. I’ll keep watching and will post as forecasts clarify what is happening.
In the meantime it’s great to enjoy the changes as they bring wetter weather – at least close to the coast – and keep an eye on the bigger picture. As those changes come through they’ll likely end up bringing some hotter weather from the inland – something else to keep an eye on. Meanwhile the grass is growing and it’s look a lot better (again just close to the coast) than it did a few weeks back.