Rain in the West, Swell in the East, and a Split Late Month Signal | 20 July 2026

[00:00:00]Good day guys. Stu from Synoptic here.

[00:00:02]It is Monday, July 20th. Had a pretty good uh weekend of rainfall uh across the western parts of Western Australia with that frontal system that moved on shore from around Friday, Thursday, Friday into Saturday, clearing out Sunday. This falls up around 30 to 50 ms along parts of the west coast. A lot of that dried out as it moved across into the wheat belt. But there's some some great accumulations there. You can see in the earlier parts of that loop falls up around 45 50 ms. Also, there's that weak low pressure system off the east coast. It's driven, you know, strong gusty winds along the northeast coast of New South Wales, southeast Queensland.

[00:00:34]Dangerous surf, massive swell. Uh, some of the recordings I've seen are up around 10 m wave heights just offshore of southeast Queensland. So, definitely be some more beach erosion as I mentioned last week was a risk with this system. At the moment, we'll see this next front sort of just skirt through towards, you know, southern parts of South Australia, progress across southern parts of Victoria, parts of Tasmania, generally clear elsewhere.

[00:00:56]We're still waiting for the signals for this late month system to form. Uh, currently we're not looking very good to be honest. Um, this might be one of those ones that was a bit over forecast, but at the moment there is some interesting signs coming from the sun.

[00:01:09]We've got a large coronal hole beginning to face Earth. So, usually within about 3 to 5 days, we'd see the effects of that. And if that's the case, if it does fire off some sort of trigger, we should still see some some stalled atmospheric dynamics where we'll see more longer duration frontal system activity or northwest cloud band or a deep cut off flow or that sort of feature moving through uh parts of the southeast into the southeast interior. So, we're still not seeing much interest in the models, but we'll just have to wait and see. Um, unfortunately it's one of those ones that I'm losing confidence in, but uh, we just have to be open and honest about that one. At the same time, if we look at the water vapor, we're still waiting for more of this moisture to build out in the west. See, this last frontal system brought the the recent rainfall in through Western Australia with the upper level trough, but we still got this deep pool of moisture building out here of um, Indonesia there. So there's also signs that this area of the ocean is starting to cool, which would lead to a positive IOD phase moving forward, but that'll still take time to build. So it' be interesting to see how this does develop, not only in the short term, but longer term, moving into the end of the year. And this this will be a key as well. um where I expect a generally favorable end to 2026 despite El Nino, I still believe that these these climate building systems out in the the central Pacific, so Enzo, El Nino, and then the positive IOD, I I don't think we'll see their effects until next year. Uh and I think it's due to the size of this El Nino that's forming. It's going to take a long time for the climate uh for the atmosphere to actually couple and that'll delay the lag time down for the eastern uh eastern parts of the country.

[00:02:49]So we'll see a dry part drier, you know, second quarter of 2026, 2027, sorry. And then at the same time, if this IOD starts to build now, you know, we're in July. It'll take 3 or 4 months to build.

[00:03:01]that'll sort of roll over into um summer even though it gets negated by the monsoon but its lagging effect then will break down into the early parts of next year. So what we saw this year where we saw the the IOD breakdown, you know, in summer and we saw that rainfall coming in through Western Australia into the present June that we just had, we'll see that again, but instead of wet, it'll be dry. And that'll compound what should be a drier 2027 nationally. And I'm just going to keep talking about this all the time for our members um to plan ahead.

[00:03:33]Uh we'll see some good spring rainfall.

[00:03:35]Should be a pretty traditional spring right through November and December.

[00:03:40]Pretty good start of the wet season, but then it should dry off pretty quickly.

[00:03:42]As soon as March ends, it'll dry off right through autumn and it'll be a long duration winter. So, I will keep talking about this. I'll put in today's update for the members with a bit more detail what to look for. But there, that's just some early signals to look for there.

[00:03:56]So, at the moment, we're still waiting for the short-term end of July system to form with low confidence. Now, as we get closer to the period, all right, this is the day by day uh for the next 10 days.

[00:04:08]Uh we're going to see the focus will be bring these frontal systems across the southern ocean. Uh so, that'll be again that far southwest, far southern South Australia, Victoria, Tasmania, and then any trade showers on the east coast. So, we'll see whenever these ridges build in the east, we see those strong winds push right up the coast. So that east coast system that was forming over the weekend, it's all all done now. Uh winds will start to ease. They'll start to push more southeasterly, pushing right up into far north Queensland, and we'll see the next front move across. So be a slight warming period in the for the country um nationally until this next ridge comes in. You'll see it starting to pull these southwesties up into Western Australia now behind the frontal system that's pushing down through the southern ocean. So where those isabars kink, that's the frontal system that was brought rain to uh Western Australia over the weekend. If we skip through this, you'll see that there isn't much really to talk about. The northeast Queensland coast should do quite well as we saw in the accumulated preip, but that'll be just consistent showers rather than a rain event. Uh same western Tasmania with each front on the back side of these highs, we'll see um you know, good rainfall accumulation on the west coast, but generally not a lot until probably Wednesday. just some really light drizzly activity for the far southeast South Australia. This this stuff across the, you know, the southern air peninsula and that this is only, you know, 1 mil. So, it's it's not really going to do anything beneficial for anyone who requires rainfall.

[00:05:30]Apparently, there's a lot of wet ground through a lot of these regions anyway.

[00:05:33]So, it might be good good chance to catch up really. Uh, less rain after a lot of rain is always a good thing. See consistent rain across western Tasmania right into Friday. Then, we have this large ridge building right across the country. So, we'll see the southeasteries rebuild along the east coast. Rain building back up for far north Queensland by Friday. Very cold conditions. Um, pretty much we watch the location of this ridge. Anywhere from Wednesday, it'll be quite cold through far southern south uh Western Australia.

[00:06:00]And as that ridge builds right across, you know, the UCLA coast into into the western parts of South Australia, we'll see some frost building right up through the interior in the northwest partial districts underneath this. And there's there's this where these dotted lines move up across this is the upper level trough underneath it. So there will be a cold pull in this. It's not significant, but with the ridge underneath being winter with the cold pool off, we'll see that that uh deeper layer of cold temperatures and that's what will get pulled right up into North Queen. So we'll see another uh cool series of nights moving into next weekend, early parts of next week for right up in the northern interior. So just be aware of that. Um what's what we're looking for though this is that upper level trough the so I had from the 26th to the 29th with this next major cycle that would see the upper level low move up through South Australia and we'll see that coupled with the northwest cloud band.

[00:06:52]So clearly from this image you can see this is probably not going to occur. Now what this tells me though is that with this deep fetch uh southwestly with the cold pool injection this is where you get your major frost risk. good snow for the Alps provided we can get a little bit of thunderstorm activity underneath that. But generally it's just going to be a cold weather outbreak. So we should see some good photography. There's a few good photographers on social media that um I follow right up through this northern parts of New South Wales, southern Queensland where there's there's this frost corridor there. So we should see some really good photography online I'd imagine moving into early parts of next week. So that'll build right up into the the end of the month into the first few days of August, right up through the eastern interior and then the next frontal systems building for the west for the first week of uh August. So again, we should see the focus of rain now pushed to the west through August. There will be activity moving through South Australia, Victoria and far southern parts of New South Wales, but rainfall will start to decrease um you know week on week in intensity or you know distribution due to the the drying effect moving into spring. So that's the sort of what to look for now.