Severe storms for SEQ and NSW, extreme WA | Australia weather Tue 3 Nov morning | Gus's Weather

Severe storms for SEQ and NSW, extreme WA fire danger, Tue 3 Nov

[c06_radar_now]

GUS G'day, I'm Gus, with your morning bulletin for Tuesday the third of November.

GUS Here's the story for most of you: severe thunderstorms are likely this afternoon for south-east Queensland and northern New South Wales.

GUS It's about 5 am in Brisbane at the time this is uploaded.

GUS This is the Bureau of Meteorology's real national radar, the whole country in one picture, not a model guess, and the newest frame is about 8 minutes old.

GUS The heaviest patch is very heavy rain west of Toowoomba in Queensland, covering about 7,900 square kilometres,

GUS with another very heavy cell south-west of Roma, and a heavy one south-west of Tamworth in New South Wales.

GUS Outside the circles on that picture, no radar can see, so I won't guess what's happening there.

GUS For the capitals, there's rain on the radar right now at Perth, Melbourne, Hobart, Canberra and Sydney,

GUS with deep storm cloud over Sydney on the satellite too, light rain at Brisbane, while Adelaide and Darwin are clear.

GUS The model's own simulated radar had an inland cell in roughly the same spot north-west of Toowoomba, so it's tracking that part of the picture well.

[c05_obs_now]

GUS Before we go further, here's what's actually been measured on the ground since nine o'clock yesterday morning, not modelled.

GUS Maryborough has picked up 35.8 millimetres of rain, Nambour near the Sunshine Coast 22 millimetres of rain, and Normanton in the north-west 32 millimetres of rain.

GUS Down south, Puckapunyal in Victoria has had 21.6 millimetres of rain and Grafton 21.4 millimetres of rain.

GUS Right now it's also raining lightly at Miles, further inland, and at Melbourne Airport and Perth Airport.

GUS The strongest gust anywhere in the country is 69 kilometres an hour, down at Casey Station in Antarctica, about as far from the washing line as you can get.

GUS All of that is measured by Bureau of Meteorology weather stations, credit to them for it.

[c07_lightning_now]

GUS Now the lightning picture, tracked by a volunteer network called Blitzortung, because strikes show where storms are actually firing, right now, even where radar can't see.

GUS Over the last six hours there have been over 3,000 lightning strikes across Australia, and the busiest cluster is near Roma in Queensland, with about 40 separate storm cells, and strikes there are holding steady.

GUS Another big cluster is sitting further south in New South Wales, and that one is growing.

GUS At sea east of Wollongong a cluster is easing off, and another offshore south-east of Nowra is holding steady.

GUS Smaller clusters are ticking over near Bundaberg and near Albury.

GUS None of this tells you if you're safe, for official warnings it's always bom.gov.au.

[c04_satellite]

GUS The satellite measures how cold, and so how high, storm tops are, that's the best way to judge how strong a storm really is, and it sees storms where radar can't.

GUS The newest Himawari picture is from about half three this morning, and away from the places already on the radar it's picking up fresh storm development too.

GUS Out near Roma that storm cloud reaches minus 65 degrees Celsius at the top, which is a seriously tall, cold storm top, well beyond an ordinary thunderstorm.

GUS Near Katherine in the Northern Territory there's a storm too, sitting right over the town at minus 59 degrees.

GUS At Katherine the satellite is showing a storm the model's own simulated radar missed by hundreds of kilometres, so this morning trust the satellite and the real radar over the model.

GUS If you're in a hurry, everything in this bulletin is indexed in the chapters in the description.

[c01_verification]

GUS Let's see how I went yesterday before trusting today's numbers too much, no hiding from the ledger here.

GUS My temperature calls across 48 towns were off by an average of 1.6 degrees, better than either the American or the European models managed on their own.

GUS The one I got badly wrong was Ceduna in South Australia, out by more than 10 degrees on a day that ran far hotter than any of the models expected.

[c02_mslp_fronts]

GUS Right, out to the weather map, where the highs and lows do their slow-motion dance.

GUS There's a weak low over south-west New South Wales near Bendigo, central pressure 1004.9 hectopascals, and it's helping draw moist north-easterly air in off the Coral Sea toward Queensland and New South Wales.

GUS High pressure sits over the Great Australian Bight at 1019.5 hectopascals and another out in the Tasman Sea, both lazy old highs just minding their own business.

GUS Up high there's a fast ribbon of wind called the jet stream over far western New South Wales,

GUS gusting to 216 kilometres an hour at that level, and that adds spin to the atmosphere which helps storms organise.

GUS Warm moist air, a weak low to lift it, and a strong jet to organise it, that's today's recipe for this afternoon's storm belt.

GUS Out in the Pacific, ensemble models are watching two patches that could become tropical lows, well east of Vanuatu and further north-east again.

GUS They're a long way from Australia and the model members are spread over 2,000 kilometres apart, so nothing to act on, just something to watch.

GUS There's also a cluster of showers out over the Indian Ocean, well south-west of Darwin, about 2,000 kilometres away, with no bearing on today's forecast, just one to watch.

[c07_cape]

GUS Time to talk fuel, the good stuff that makes storms grow.

GUS Meteorologists measure the energy stored in warm, moist air and call it CAPE, think of it as the petrol in a storm's tank.

GUS There's also plenty of moisture: the air holds about 38 millimetres of what's called precipitable water,

GUS roughly how much rain would fall if you wrung every drop out of the whole sky above you like a sponge.

GUS It's a genuinely wet atmosphere up there.

GUS Near Armidale it's a similar story, about 2,000 joules per kilogram on tap, plenty for tall storms there too.

[c08_skewt]

GUS Energy alone doesn't make a storm, something has to break the lid.

GUS Picture a saucepan with a lid on, warm air aloft can act like that lid and stop the hot bubbles of air below from rising. Forecasters call it the cap.

GUS Near Gympie, about sixty kilometres inland from the Sunshine Coast, the lid's gone too, so storms fire early afternoon.

GUS Near Armidale it's the same, a weak lid, so storms should fire there too.

[c11_shear]

GUS Storms also need the wind to change with height as you go up, called wind shear.

GUS Picture spinning a top, a gentle shove and twist makes it spin upright instead of just wobbling, wind shear can do that to a storm.

GUS Near Armidale it's around 68 kilometres an hour of shear, still plenty to work with.

GUS Fuel, a weak lid and strong shear together is the recipe for storms that can bring large hail and damaging wind gusts, not just a passing shower.

[c12_index_map]

GUS Gympie's supercell and hail numbers are high too.

GUS Near Armidale, slightly lower, still worth watching.

GUS None of this promises a rotating storm touching down, here we just say a storm that starts to spin. It's guidance on the environment, not a guarantee of what happens on the ground.

[c15_rain_wind]

GUS Let's run through how today actually plays out, in order.

GUS Gympie also sees storms fire first, with rain that's hit and miss.

GUS A little later this afternoon, it's Armidale's turn, the same mix of hazards.

GUS By this evening, the heaviest rain rate of the day is expected further north-west, up to 87 millimetres an hour at its peak, that's torrential.

GUS At the Gold Coast there's a wind change due around 4 pm, winds swinging from the north-west to the south-east with temperatures dropping about 5 degrees, a sea breeze and a cooler change arriving together.

GUS The strongest gust of the day, about 77 kilometres an hour, is expected this evening south of Rockhampton.

GUS Separate storms can also join into one bigger cluster overnight, called a mesoscale convective system, think of lots of small storms merging into one long-lived mass.

GUS That's why some coastal towns can get a late soaking while their neighbours miss out entirely.

[c19_model_compare]

GUS How much confidence do I have in all this? Let's compare the three models I use: the American GFS, the European model, and the European AI model.

GUS For Armidale, confidence is lower, around a 43 per cent chance of meaningful rain.

GUS The ground under those Queensland storms is already very wet, Brisbane's had about 26 millimetres of rain in the past week,

GUS so there's not much left in the soil to soak up, any heavy burst could run off fast and spike creeks.

GUS That estimate comes from SILO, the Queensland Government's climate data service.

[c92_river_gauges]

GUS A look at some rivers around the country, levels and trends only, not flood categories.

GUS The Bulloo River to Quilpie and at Quilpie in Queensland is steady at 4.04 metres and carries a moderate flood warning from the Bureau, worth watching if you're nearby.

GUS In South Australia the Gawler River at Virginia is rising, now at 1.67 metres.

GUS Myrtle Creek at Rappville in northern New South Wales is rising too, though still low at 0.3 metres.

GUS Tasmania's Derwent below Meadowbank is steady at 1.81 metres, and in Victoria the Goulburn River at Shepparton is holding near 2.9 metres and rising slightly.

GUS Credit to the Bureau of Meteorology's flood warning network for all of those readings.

GUS And a moderate flood warning covers the Barcoo River to Isisford, the Barcoo River at Blackall and the Barcoo River further downstream.

[c90_events]

GUS The Bureau of Meteorology has an extreme heatwave warning out for the Kimberley, Pilbara and North Interior districts of Western Australia, as of 4:05 this morning.

GUS That's the Bureau's top heatwave category, forecast to be intense and prolonged enough to affect even fit, healthy people,

GUS with three or more days where it barely cools at night, serious for anyone across that stretch of Western Australia.

GUS The Bureau also has a severe heatwave warning out for the Carpentaria district, also current as of this morning's update.

GUS A severe heatwave warning is one step below extreme, but it's still enough to affect people who are elderly, pregnant, or already unwell, so it's worth checking on anyone vulnerable in that district too.

GUS There's also a severe heatwave warning for the Peninsula, Gulf Country, Northern Goldfields and Upper Flinders districts.

GUS There's a moderate flood warning current for the Balonne River, affecting the town of Surat and the gauge at Warkon, so if you're near that river it's worth keeping an eye on the levels today.

GUS There's also an extreme heatwave warning for the Tiwi and Arnhem districts near Darwin.

GUS The full detail on every one of those is at bom.gov.au.

GUS On today's events, Royal Randwick in Sydney has a real severe storm signal for the Spring Carnival meeting, know where the shelter sheds are.

GUS At Flemington for Melbourne Cup Day, rain is likely even if light, and winds up to 38 kilometres an hour, so brollies more than fascinators today.

GUS In Newcastle this evening, AFC Elite also carries a thunderstorm risk with around 6 millimetres of rain expected.

[c16_index_map]

GUS Now the fire risk, because that heatwave and extremely dry country go together in the north-west.

GUS South of Broome in Western Australia, the fire danger index, which blends heat, wind, dryness and how cured the vegetation is, reads at the extreme end, peaking even higher at one point.

GUS The drought factor there, a measure of how dry the landscape is from past rainfall, is at its maximum, ten out of ten, so anything that gets going out there has plenty to burn.

GUS That's remote country well south of Broome, and the real risk there is to roads, stock routes and the stations and communities out that way.

GUS If you're in that part of the Kimberley, check bom.gov.au and your local fire authority today.

[c21_town_table]

GUS Time for the lap of the capitals, both the overnight low and the daytime high, plus the rain, because a number without its word isn't much use to anyone.

GUS Brisbane's low was 20 degrees, today's high a top of 26 degrees, with just 0.6 millimetres of rain, basically nothing.

GUS Tomorrow warms to 32 degrees with a storm risk and about 22 millimetres of rain, so keep the washing watched and an umbrella handy.

GUS Sydney's low was 19 degrees, high of 26 degrees today, with about 4 millimetres of rain, and that severe storm risk at Randwick this afternoon, so have a shelter plan.

GUS Tomorrow's high eases to 24 degrees with around 14 millimetres of rain likely.

GUS Melbourne's low was 13 degrees, high just 19 degrees today, with a small amount of rain, about 4 millimetres, a cool one for Melbourne Cup Day.

GUS Tomorrow warms to 22 degrees and should stay largely dry.

GUS Perth's low was 16 degrees, high 21 degrees today, with about 2 millimetres of rain around lunchtime, nothing to change your plans. Tomorrow's warmer, a high of 25 degrees.

GUS Adelaide's low was 12 degrees, climbing to a high of 20 degrees today, dry all day, so Adelaide's staying dry enough the rain gauge might file for long-service leave.

GUS Tomorrow's cooler, a high of 19 degrees, still no rain of note.

GUS Darwin's low was 27 degrees, high 35 degrees today, with about a millimetre of rain, that's inside the heatwave warning I mentioned earlier, so keep up the fluids and check on anyone vulnerable.

GUS Tomorrow's much the same, a high of 36 degrees.

GUS Canberra's low was 11 degrees, high 22 degrees with a touch of rain too, similar again tomorrow.

GUS Hobart's low was 10 degrees, high just 17 degrees, barely half a millimetre of rain, a quiet one down there.

GUS Hobart's had a quiet, settled run of it the last day or so, nothing dramatic either way.

GUS Hobart stays quiet and settled, a good one for a slow cuppa on the waterfront.

[c20_plume]

GUS Now let's look further out, from Wednesday through to next Tuesday.

GUS This comes from a European model's nine-day rain forecast, it only tells us about rain, not thunderstorms or hail, so I'll flag separately where the storm ingredients show up.

GUS In south-east Queensland, Wednesday and Thursday look dry, but by Saturday the stored storm energy we looked at earlier returns,

GUS and the models disagree on whether it actually rains, so there's plenty of fuel but nothing certain to set it off. Sunday and Monday look quiet.

GUS Central Queensland is quiet most of the week until Sunday, when energy builds again near Rockhampton, the same uncertain picture.

GUS North Queensland carries that same signal from Friday through Sunday, but confidence is only a guide this far out.

GUS Northern New South Wales looks quiet the whole week.

GUS The Top End is the standout, with big energy numbers building daily from Friday and both models agreeing it turns wet, with totals around 13 to 17 millimetres some days.

GUS That's the build-up season, the old trade winds that bring the dry season swing north-east and get cut off, so steady rain gives way to hit-and-miss afternoon storms until the proper monsoon arrives in December.

GUS South-west Western Australia and Victoria and Tasmania both look fairly quiet, just a showery signal around Melbourne and Launceston midweek.

GUS For the weekend that matters most: south-east Queensland's Saturday is the day to watch, storms are possible.

GUS Canberra and Melbourne look quiet through the weekend, maybe a passing shower in Melbourne. I'll update it next bulletin.

[c02_mslp_fronts]

GUS Confidence overall today is high, which in plain words means the models broadly agree on the big systems and the quiet spots, so I'd trust today's call more than most.

GUS It's really the exact placement of this afternoon's storms where I'd allow some wiggle room, so if the clouds tower and darken fast, that's your sign, don't wait for an official warning to take shelter.

GUS Saturday also looks quiet for most of the southern capitals, about as much drama as a lawn bowls final. I'll see myself out.

GUS Here's today's sky-spotting homework: watch for towering cumulus clouds building hard before lunch over the inland ranges, that's usually the first sign the lid has broken and storms are properly underway.

[c06_radar_now]

GUS For all the official warnings, check bom.gov.au.

GUS The next bulletin is this afternoon.

GUS If you'd like to subscribe, I'd appreciate it, and if you've got a weather question, pop it in the comments and I'll get to as many as I can during the day.

GUS Tell me in the comments what the sky's doing where you are too, I do read them.

GUS Gus's Weather is a PandaVision production.