00:02Hello Australia, it is Sunday the 25th of October and this is your weather update for the week ahead.
00:08There is severe weather across much of Australia with a lot of severe rainfall this week, okay?
00:15So looking here at the accumulations we can see that much of the eastern part of the country will receive
00:2025 to 50 mils,
00:21with pockets in Queensland and in some of the range areas receiving anywhere from 50 to 100 mils possible.
00:28So that is a lot of rain on the way that has been associated with sheep graziers warnings, severe weather
00:33warnings, thunder, lightning,
00:35possible hail and flood warnings, especially in the Queensland southern regions.
00:39I expect that to continue for a lot of this week, especially those flood warnings in Queensland as there is
00:44still a lot of moisture in the air.
00:46Before I get through into this weather, this daily sort of weather breakdown this week,
00:52I thought I'd discuss why is there so much moisture available at the moment.
00:55It's because of a few reasons really.
00:57We're going to start here looking at the Bureau's current weather map or their analysis chart,
01:01and to look just at the surface level pressure of what's happening and then we'll discuss some of the upper
01:05level dynamics.
01:06So we have a cold front that's moved through the south and this is connected with a trough over the
01:10interior of the country.
01:11So those low pressures are what is a really key ingredient to driving rainfall.
01:16But in order for there to be rainfall and such soaking rain that we're seeing, there also has to be
01:20moisture available.
01:21And there's, I suppose, a few reasons why we have moisture available.
01:25First is that we have this feed in from a warm Indian Ocean.
01:28So that's providing that tropical moisture there from the Indian Ocean.
01:32However, we also have this stationary high sitting in the Tasman delivering onshore flows.
01:37So also delivering this warm, moist air that's travelled in from the Coral Sea and from the Pacific as well.
01:43So we have those two feeds of tropical moisture coming in.
01:46And then we have this low pressure over the interior of the country that's allowing those to eventuate.
01:52The other reason that it's so strong is because there's quite warm air from these northerly flows.
01:56And warm air is a really key ingredient to getting convective systems, convective systems being what is what drives some
02:04thunder and lightning storms.
02:05So those are, I suppose, a lot of the ingredients occurring behind the severe weather that we're seeing at the
02:11moment.
02:12OK, let's have a look at the day by day breakdown of what's occurring.
02:14So this is Sunday.
02:15It does seem to be the worst day for the southeast regions as that front moves through into Monday.
02:20Today, most of the southeast has dried compared to that Sunday rainfall.
02:25But northern New South, northern New South Wales and southern Queensland still a lot of rain on the way.
02:28And then we have another sort of low pressure system in WA driving this moisture band here in the Northern
02:34Territory.
02:35All right, trough action over the interior of the country for Tuesday, Wednesday, Thursday.
02:42You can see this cutoff low now sitting over South Australia and again continuing up into a lot of this
02:47severe weather in the territory.
02:50Cool. Friday, we start to see it coming back over again into Queensland.
02:53So that's why I say those flood warnings will likely continue to be issued throughout the week, even if there's
02:58a day or two that you get a bit of break from the rain.
03:00Here, Saturday as well, rain on the way here.
03:03You can see the high pressure system in the Bight moving over.
03:05That should hopefully dry out the east coast into the start of next week.
03:09And you can start to see a little bit of that dryness on the way there for Sunday, but still
03:13just heaps of moisture available.
03:15If you take anything, it's a wet week ahead.
03:17I've not seen super significant winds on the way, but there are still definitely moderate to strong winds on the
03:26way with a lot of that rain.
03:27So definitely something to be considerate of.
03:29As for the hot temperatures that we saw last week, we're not going to see as much heat across most
03:34of Australia this week.
03:35The rainfall has definitely cooled it down, but it's quite humid.
03:38So even though for a lot of, say, for example, the southeast, we're now in the 20s.
03:42It's that humid heat.
03:44So definitely still something to be conscious of when you're working outdoors.
03:47All right.
03:47That is it for the weather update.
03:49I thought we'd touch in this week in our long term forecast with the Indian Ocean Dipole, because this is
03:55the first time I've seen a consistent trend called for many, many months now.
04:02So for months, we've seen the Australian and the Japanese models and a lot of other models as well diverge,
04:06whether it's going to be a positive or a negative IOD.
04:09This is the first time I'm seeing these two models both trend negative.
04:12So Japan into a negative IOD wetter and the Australian at least going into a neutral.
04:16This is good news and possibly one of the reasons why it's been such a wet El Nino year.
04:22Definitely something we can chat about more if you're curious why it's been such a wet year, even though we
04:27have an El Nino being called.
04:29All right.
04:30The other thing that I want to highlight is with our seasonal forecasting.
04:35So we're looking here at this week, essentially, the 29th of October to the 4th of October.
04:39This model was run on the 22nd, so three days ago from when I'm videoing this weather update from the
04:45Bureau's Access S2 model.
04:49And why I'm bringing it up is that I want to talk to my colleagues further to discuss why this
04:55model is showing that it's unlikely to exceed median rainfall across much of Queensland
04:59when we know through the numerical weather processing or the numerical weather forecast, which is our short term models, that
05:06there's a lot of rain on the way this week.
05:07So why I wanted to bring that up, even though I don't have answers, is to show you what scientific
05:12discourse is like.
05:14I suppose to acknowledge that I'm not an expert of seasonal forecasts and how they operate or run.
05:19Neither are most of the people that write articles about it that you're reading online.
05:25However, you know, often independent, singular people will make an analysis from this.
05:29And just to show you that as a scientist that I would not go and make, you know, judgment calls
05:35about things without consulting with my colleagues first.
05:37So the point of this is that something funky is happening with the models.
05:42I will come and investigate that this week with my colleagues and next week hopefully let you know why it's
05:48showing to be so dry, even when we know it's quite a wet week ahead.
05:51So I'll leave you on that little piece of, I suppose, future analysis to occur.
05:56Okay, finally, let's wrap up here.
05:59Just looking at the rainfall totals again to show you lots of rain on the way this week.
06:03So severe weather, definitely possible.
06:05Please be safe.
06:06Have a good week.
06:07And we will see you next time.
06:08Bye.
06:09Bye.
06:09Bye.
