Australia: This Extratropical System Is Getting Massive...

本站添加: 2026-05-22

[00:00:01]Good day folks. It's Josh here from Cyclones Oz and this is your latest forecast update Australiawide for the 21st of May 2026. A significant day of weather is happening across Australia today. Lots of cloud coming in from the northwest. All bark, no bite. Low pressure expected to dominate over the east over the next couple of days. And then as we headed towards next week, low pressure is expected to develop into the southeast bringing some muchneeded rainfall potential to South Australia, Victoria, New South Wales, and maybe even Queensland, too. Uh before I go any further, if you are brand new to my channel, please do consider subscribing.

[00:00:30]But let's get stuck straight into the details right now, which if you are watching the first 20 seconds of the video, you would know is that massive low off the east coast. This one is going to be quite significant both in terms of uh intensity, but also in terms of impacts for particularly northeastern New South Wales. Definitely a story that I'd like you to pay attention to. So currently, if we turn on the satellite imagery right now, we're beginning to see the first signs of an area of low pressure beginning to develop here offshore from the far northeastern New South Wales coastline, it's just towards the northeast of Lord How Island right now. A lot of convective thunderstorms on the storm's eastern flank here along a trough and an area of low pressure now beginning to develop under this area of thunderstorms here adjacent to that trough. We've also got a pretty strong southerntherly flow on the back side of the system here running up the New South Wales coast into pockets of southeastern Queensland. And whilst this isn't translating to any rainfall or any meaningful rainfall for land areas, it is producing some juicy thunderstorms offshore from far northeastern New South Wales in an environment that is quite unstable. And that was especially the case last night with a couple of these storms running up the Brisbane coastline with some pretty significant rainfall accumulation estimations in them. So interesting stuff. Definitely some interesting times. You can see as we continue to push through this forecast modeling through today and into tomorrow that low really does begin to properly develop. Norfolk Island and Lord How Island are going to be coping a beating from this. And if you are on Lord How Island or Northfolk Island, let me know in the comments section down below or feel free to flick me an email at josh joshh.cscyclones.com.au and let me know what the conditions are over there. Definitely some interesting weather, I'd imagine on those two islands. It does look like this low will get uh to its peak intensity sometime tomorrow about 999 hectar pascals. This is not a strong low by any stretch of the imagination. We're pretty used to seeing low pressure systems into the 980s and every now and then into the 970s into the Tasman Sea. So, let's not get ahead of ourselves and believe that this is a record-breaking low pressure system or an East Coast low because it's neither of those things. This is just a standard Tasman Sea low. But, it is a large one and it is going to be packing a bit of a punch particularly to northeastern New South Wales. And the reason for that is if we pan down towards the south, you can see a high pressure system here into the southern Tasmin Sea. on a meteorology scale, not very far away from where that low pressure system is, which means we've got a very tight pressure gradient here, adjacent to the New South Wales and adjacent to the Queensland coastline where this low pressure system is coming through. You can see 1,000 hectascals here and about 1,020 heaptop pascals here. No more than about 8 or 900 km away from each other. Doesn't sound like a big difference, but on a meteorology sense, that is a pretty big a pretty steep gradient. And when we've got those tight pressure gradients, that's where our severe weather tends to hang around.

[00:03:03]And that's especially going to be the case into northeastern New South Wales because of that southerntherly flow thanks to that high pressure system. So that high pressure system will aid the low pressure system cyclonic rotation and that's going to produce an area of very strong southerntherlys or southsoutheasterly running up into northeastern New South Wales. And because the northeastern New South Wales coastline kind of juts out into those winds, you can see it's not a real south to north coastline. It's more of a southwest to northeast coastline.

[00:03:29]because it juts out and remains a bit more exposed to these winds, it's actually going to feel the brunt of this low pressure system, even though it is a long way offshore. So, expect some squaly showers to develop through today and into tomorrow uh morning. And these will reach their, I guess, quote unquote peak intensity through tomorrow afternoon and tomorrow evening with gusts likely to approach 90 or even at times 95 km an hour. We'll also likely see some pretty big seas and swells adjacent to this low pressure system.

[00:03:53]seas are expected to exceed six, maybe even 6 and 1/2 mters here adjacent to the Queensland, New South Wales coast. A little bit closer to the coastline, they drop back to about 5 mters, but still pretty big. The protected waterways around the Gold Coast in and into the Morton Bay area adjacent to Brisbane will likely be a lot smaller than that.

[00:04:09]Maybe 3 mters for the Gold Coast, less than a meter for the Brisbane local waters area. But northeastern New South Wales will definitely cop a bit of a battering here with some very large and powerful season swells expected to buffet the coastline through Friday. And you can see this really doesn't ease off much through Saturday. Still some large and powerful sea and swell conditions expected on Saturday. It should begin to drop down a little bit for Sunday. The good news is at least for southeastern Queensland, the boat show is not likely to be a wash out. You can see rainfall accumulations this weekend are actually expected to be very minimal. And again, that is because of the coastline's kind of placement here and the fact that these showers are going to run up parallel to the coastline. So maybe clipping New South Wales, which means coastal areas could pick up some halfway decent rainfall accumulations. More rainfall that they don't really need here along the coast. But Queensland has pretty much zero hope of picking up significant rainfall. No more than 10 mm should fall anywhere on the southeast Queensland coast. Bar maybe po uh the um Morton Island, sorry, the observation center there, but falls between 30 to 50 millimeters, not out of the question from about Cape Baron down to Newcastle.

[00:05:08]The heaviest rainfall accumulations will be concentrated between Port Mcquaryy and Coffs Harbor where the coastline kind of sticks out a little bit more.

[00:05:14]But again, strictly coastal inland areas not seeing any rainfall at all. Places like uh Norfolk Island and Lord How Island could pick up closer to 100 mm of rainfall if this low pressure system remains strong and are quite stable over those regions. But you can see we do have some halfway decent winds right now. Gusting 69 km an hour now at Lord How Island. So not too bad at this point in time. Definitely pretty blustery in those areas.

[00:05:37]This low pressure system will be pretty quick to weaken off towards New Zealand through Sunday and into Monday. You can see that they're pulling away. And then we are expecting another low pressure system to kind of slip through the cracks between those high pressure areas or those areas of high pressure towards the west and the east of southeastern Australia. This is interesting and it should allow for some rainfall to develop towards the end of May here through South Australia, Victoria, and New South Wales. This is also a new addition to the forecast modeling. We didn't really see that yesterday. So, let's have a look at how this eventuates. High pressure currently the dominant force situated over over Victoria moving into Tasmania tomorrow.

[00:06:10]That's going to keep things uh calm and fine. And then heading in towards the warmer side of things through Sunday and or Saturday into Sunday. We then begin to see a bit of a weak trough move in between these two areas of high pressure. An area of high pressure over where my face cam is and an area of high pressure down in the far south uh eastern corner of your screen here into the Tasmin Sea. And that's what we've been talking about through the last couple of weeks. High pressure will remain the dominant force across southern Australia, but we will see areas of low pressure, which means rainfall and more turbulent weather slip through the cracks between those areas of high pressure. And this is a good example of that. Through Saturday and Sunday, we'll see this area of low pressure develop. It's going to be a very weak one. Definitely not severe in nature before approaching the Bass Strait, Victoria, and South Australia through Monday, Tuesday, and Wednesday.

[00:06:52]And it's expected to be one of those interesting cases where it kind of hovers around, doesn't really do an awful lot, and maybe interacts with other areas of troughing and low pressure. put simply a very complex forecast here for southeastern Australia after this coming weekend. And it's probably going to take another couple of days for us to really figure out what's going to go on here. But low pressure does look to come back uh and return to southeastern Australia through Monday, Tuesday, and Wednesday. And that's a congruent picture between all major forecast models. You can actually see the GFS has that low pressure center there on Tuesday afternoon. The EC has it about 100ks towards the or maybe about 50ks towards the west. excellent forecast model congruency and that tells me that low pressure is returning probably sometime Monday or Tuesday next week and that will definitely translate to some rainfall. You can see here whilst this definitely isn't an all a full-blown east coast low or a significant allout severe weather event on the forecast, it will likely translate to some halfway decent rainfall accumulations at least for a brief stint of time. And a couple of coastal areas could pick up 50 or 100 millime of rainfall with inland more rural and agricultural uh placements picking up closer to 20 or 30 millime of rainfall. And considering it's going to fall over multiple days, that's most likely to be on that more sort of soaking side of things, which is the rainfall that these agricultural regions really do need at this point in time.

[00:08:05]One thing that does concern me is any low pressure system on the Tasman Sea side of things. So adjacent to New South Wales, Victoria is going to have an absolute field day with the amount of moisture that's currently coming off the East Australian current into the Tasmin Sea. This would be quite a concerning picture if we saw an area of low pressure developing down here around southeastern New South Wales, especially if it was to stall or sit in the same location for a couple of days. It would drive an incredible amount of cloud and subsequent rainfall into the southeast coast. Uh, and whilst forecast models won't be able to discern that until maybe the day or the day before of the event, it will very much likely translate into a significant flooding concern. So, this will be an area that we're going to keep a very close eye on around the 25th and the 26th of May. we could be on for a significant rainfall event down here, maybe 100 millimeters or so through southeastern New South Wales and far eastern Victoria if a low pressure system can develop adjacent to those uh previous uh locations. So, we'll keep an eye on that situation there. But definitely something that has me quite concerned if something does get going and I'll just show you why. See temperatures 21 pushing 22° even 23° when you get up to about the Sydney latitude. That is unseasonably warm for this time of the year. Very much above average. And as we've been talking about, whilst El Nino is expected to develop and that typically favors dry conditions, particularly through far southeastern Australia, this is going to be our get out of jail free card. This will be our saving grace for rainfall for coastal locations, particularly through New South Wales, but also into Victoria and maybe even Tazzy as well.

[00:09:28]I've got a whole video explaining that.

[00:09:30]You'll see that at the end of this one.

[00:09:32]So, please do consider watching it if you are still left confused.

[00:09:35]Interesting. Interesting. Interesting.

[00:09:37]Uh we'll talk about northern Australia in just a second because I do want to get through in a bit of a detailed sense what's actually happening up there.

[00:09:43]Quite a bit of unseasonable rainfall potential today. But sou south southwestern Australia rather we do have a weak advancing cold front that's going to brush up against the southwestern coast in the next couple of hours or so.

[00:09:53]And it's dragging with it quite a lot of instability which means the southwestern land division today has a chance of seeing a couple of thunderstorms one or two of which may go severe for briefly damaging winds or even some heavy rainfall. Some brief periods of heavy rainfall particularly for this time of the year. not something that we see every single day or with every single coldront passing through. Areas of rainfall now beginning to develop adjacent to the southwestern LA visions.

[00:10:14]Forecast modeling is pretty weak on this. But you can see as this system moves up to the coastline here through this afternoon and into this evening, there will be some areas of shower and thunderstorm activity moving through the southwest land divisions, particularly along the south coast between Augusta and Albany and also potentially around the Perth metro area as well. Convective allowing forecast modeling is always interesting to see at this time of the year with these sort of frontal setups.

[00:10:37]But you can see convective allowing modeling or the access sea is really only calling for the south coast to pick up any thunderstorm activity if thunderstorm activity can even uh you know get itself off the ground. And the reason for that is warm ocean waters here will mean increased humidity and increased due points. That forcing that we're going to see from the cold front.

[00:10:53]Of course, cold fronts come through like a wedge and they wedge air upwards when they move through. And that rising motion is going to generate that lift uh that's needed to get convection or cloud activity off the ground. And also a little bit of instability from those northerlys which have brought a lot of warm air down from the subtropical regions in the last couple of days. 26° yesterday. An absolute pear of a day across most of the southwestern land division. Uh and it does look like that lingering heat is going to help in producing a couple of these thunderstorms. Um convective available potential energy today is not that bad.

[00:11:23]We do have quite a bit of instability particularly around the Perth Peele region up to about 500 jewels per kilogram Cape. That's very good for this time of the year. Cape values rise as you get further towards the north but it's not likely to translate into anything. The limit of rainfall potential is about Gilderton anywhere further north. So Geraldton and Calary very limited rainfall potential uh in today's setup. Uh it doesn't look like anything is going to make it up there.

[00:11:45]Anyways, northern Australia as promised we do have a little bit of outofse rainfall potential and that is all thanks to this massive area of cloud.

[00:11:52]Again, like I said at the start of the video, all bark, no bite. I mean, have a look at this area of cloud that's beginning to move into the Northern Territory, Western Queensland and pockets of South Australia. There is no rainfall to speak of in this cloud system at all. We do, however, have a bit of a coastal trough offshore from the Pilra and the Kimbley coastline. And as you can see, that is translating to a couple of areas of shower and thunderstorm activity today. And throughout the course of today, we will actually see a couple of areas of showers and thunderstorms developing around the Port Headland and Karatha areas, most likely towards the north of Karatha. And then eventually some lighter rain later this afternoon and into this evening moving into the northern Pilbur region and then eventually into the north interior through the early hours of tomorrow morning. Again, not much is expected to come from this event here. Maybe 10 mm tops. Coastal locations, you really have to pick your spots if you're going to see any rainfall, but a couple of areas could see 10 to 40 mm if we do see the right shower and thunderstorm activity moving ashore. Again, this is nothing severe or crazy, but it is a little bit of late season rainfall that these areas most certainly won't be saying no to. An interesting thing actually is if you have a look at the broom radar right now, there is a lot of rainfall on the broom radar, but initialized poorly by the major forecast modeling, uh it does look like the area around Broom and the Dampia Peninsula as a whole might actually pick up a little bit of rainfall today. Uh and some halfway decent falls as well between 10 to 15 mm. So that'll be interesting to see if that does come off. But the focus is going to be on where that low pressure trough is kind of focused. And right now that is well and truly offshore. And as a result, all the rainfall is expected to linger around that area of low pressure, which means that it will remain for the most part offshore at this point in time. Pretty interesting.

[00:13:22]And then after that, very limited in the way of rainfall potential here from about this weekend onwards. You can see that dry pattern now very much beginning to take hold here through northern Australia. And that is going to be just thanks to that persistent southeasterly flow that we're getting to see into the dry season. There is no real signal of rainfall here across Queensland, the Northern Territory and Northern WA from about the 23rd or the 24th of May onwards. So this weekend onwards, it is completely dry. And this I believe to be the true start of the dry season. No more showery stuff. Maybe apart from up in far northern Queensland, but no more showery stuff for the Northern Territory. Definitely nothing more for Western Australia. It looks like it is going to be high and dry up here. And that dry season is going to be quite a long one this year by the looks of things. We'll keep an eye on that situation as well. We'll have further updates if they're needed, but I'm going to wager a bet that they're probably not going to be needed until at least August or September. Anyways, that will do it for today's weather forecast update.

[00:14:14]Just a reminder, 31st of May. Website is going live and our premium subscription service is going live. A bit of a bummer. The prices have had to go up.

[00:14:22]Again, that's just development costs at this point in time, but also a couple of coding errors on my part. I'm going to find a way to make up that value for you. So, it is still effectively uh the best value that you can get. It's still the cheapest. I mean that that let's not get ahead of ourselves. It is still the cheapest weather subscription around Australia in my humble opinion the best, but it has gone up a little bit. So I do apologize that all the details will be coming out in a separate Facebook post shortly. But if you do want to check it out, let me know. Flick me an email and I'll give you some early access. But that'll be it for me today. Have a wonderful what is it today? I say this at every video Thursday and I'll catch you on the next storm. Goodbye.