Catastrophic fire danger, Qld flooding | Australia weather Mon 2 Nov morning | Gus's Weather

Catastrophic fire danger, Qld flooding, storms building Tuesday

[c06_radar_now]

GUS G'day, I'm Gus, a robot, and this is your morning bulletin for Monday the 2nd of November.

GUS The big story today is catastrophic fire danger over western New South Wales this afternoon, flood warnings still running on Queensland rivers,

GUS and storm ingredients building for tomorrow near the New South Wales coast and south east Queensland.

GUS It's about 6 am in Brisbane at the time this is uploaded.

GUS This is the Bureau of Meteorology's real national radar, the whole country on one picture, not a model, and the newest frame is about 9 minutes old.

GUS The heaviest rain is east and south east of Adelaide in South Australia, very heavy at times, with another very heavy patch just north of Chinchilla in Queensland.

GUS There's a heavy patch north west of Horsham in Victoria, one near Darwin, and also a patch of rain offshore over the Tasman Sea, about 40 kilometres south of Wollongong,

GUS moderate in strength and covering a modest area, drifting further out to sea and expected to stay offshore, so it's one for shipping to note rather than anyone on the coast.

GUS Of the capitals, Adelaide and Canberra have rain on the radar, Sydney and Brisbane a light patch, Perth, Melbourne, Hobart and Darwin clear. The model's own simulated radar agrees on that South Australian patch.

GUS Tell me in the comments what the sky's doing wherever you are right now, I'll read a few through the day.

[c05_obs_now]

GUS Here's what Bureau weather stations have actually measured falling since 9 this morning, not a forecast, the real thing.

GUS Kangaroo Flats in the Northern Territory led the way with 39.4 millimetres, Gayndah in Queensland had 33,

GUS and Mount Crawford in South Australia had 14 millimetres with a wind gust of 56 kilometres an hour, the strongest gust measured anywhere this morning.

GUS That's the measured picture from stations right across the country this morning. The forecast charts coming up show what's likely next, not what's already fallen.

[c07_lightning_now]

GUS Lightning is tracked by the Blitzortung network, a volunteer set of sensors around the world, and I'll credit them once here.

GUS Over the last six hours Australia has had about 600 strikes picked up, and about 80 strikes in just the last hour, so fairly steady overall.

GUS The busiest patch is about 190 kilometres east of Adelaide, near Bordertown, and it's growing, matching that heavy rain on the radar.

GUS There's also scattered lightning near Kununurra and Emerald, and a couple of patches out at sea.

GUS Lightning safety and any warnings always come from the Bureau, at bom.gov.au.

[c04_satellite]

GUS Satellite measures how cold a storm's top is, and the colder it is, the taller and usually stronger the storm.

GUS The coldest cloud right now is far out over the Indian Ocean, about 1,300 kilometres north west of Broome, colder than minus 76 degrees Celsius.

GUS There's a second one over the Timor Sea, about 200 kilometres west of Darwin, around minus 57 degrees. Both are a long way from anyone.

GUS This is the real measurement, not a model, so out there this morning the satellite is what you should trust.

GUS None of the capitals have deep storm cloud overhead right now, nothing colder than about minus 30 degrees anywhere near Sydney, Melbourne, Adelaide or Canberra.

GUS Everything in this bulletin is indexed in the description, so if you're in a hurry, jump to the part you want from the chapters there.

[c01_verification]

GUS Quick check on yesterday's forecast, using the Queensland Government's SILO network of actual observed weather.

GUS Overnight lows came in close to what I said almost everywhere, mostly within about a degree.

GUS Rain was the weak spot. I'd called showers for several capital cities that mostly stayed dry, so the models I lean on were a bit too keen on rain.

[c17_temp]

GUS The Bureau has several heatwave warnings out this morning, as of 4:36 am Brisbane time, and these are about dangerous, prolonged heat, not just a hot day.

GUS There's an extreme heatwave warning for the Kimberley and North Interior of Western Australia, and a severe heatwave warning for the Pilbara District, covering towns like Karratha, Port Hedland and Newman,

GUS where afternoon temperatures sit well into the forties for several days running with little cooling overnight, which the Bureau rates as dangerous for anyone outdoors, for older people, young children and pets.

GUS That Pilbara warning stays current over the next couple of days rather than easing, so keep checking on vulnerable family, friends and animals, and avoid strenuous outdoor work in the early afternoon.

GUS There's also a severe heatwave warning for the Northern Territory's Daly, Tiwi, Arnhem and Carpentaria districts around Darwin.

GUS And a severe heatwave warning covers Queensland's Peninsula and Gulf Country districts together with the Northern Goldfields and Upper Gascoyne in Western Australia, all facing several days of dangerous heat.

GUS Up near Broome the model has daytime highs around 44 degrees, and Darwin itself sits in the low to mid thirties with a muggy overnight low near 26.

GUS If you're in any of these warning areas, check on elderly neighbours, pets and livestock, and drink more water than you think you need. Warnings are at bom.gov.au.

[c92_river_gauges]

GUS The Bureau has moderate flood warnings on several Queensland river systems, including the Condamine, Warrego, Barcoo and Bulloo; a moderate warning means some low lying roads and paddocks near the river can go under.

GUS The Condamine at Chinchilla Weir is at 7.81 metres and rising, that's the height of water on the gauge, not how deep it is at your place.

GUS The Bureau has a moderate flood warning for the Bulloo River to Quilpie, with the gauge at Quilpie reading 4.23 metres and holding steady, affecting some low lying grazing country and station roads nearby.

GUS There's also a moderate flood warning for the Warrego River downstream of Charleville, where the gauge at Baker is rising slowly, affecting low lying paddocks and some roads along the river.

GUS The Barcoo River also carries a moderate flood warning through to Isisford, with the gauge at Blackall at 3.82 metres and easing, so levels there are coming back down.

GUS Elsewhere, the Macintyre at Terrewah in New South Wales is falling, the Dumaresq at Bonshaw is rising, and in Tasmania the Derwent and Forth Rivers are rising a little.

GUS Near the other capitals the rivers are quiet, steady through Melbourne, Perth and Adelaide, and rising slightly near Darwin. River heights come from the Bureau's flood network, credited once here.

GUS Brisbane's ground is already quite wet this week, about 43 millimetres of rain, so more of any new fall runs off rather than soaking in, an estimate from SILO, the Queensland Government's climate service.

[c16_index_map]

GUS This next bit isn't a laughing matter, so no jokes here. The Forest Fire Danger Index blends heat, wind, dryness and dry fuel into one number.

GUS Catastrophic fire danger, the Bureau's top category, is forecast near Broken Hill in western New South Wales this afternoon,

GUS with temperatures near 35 and a half degrees, humidity near 9 per cent and gusts near 84 kilometres an hour.

GUS In catastrophic conditions any fire near homes, stock or roads would be extremely hard to control,

GUS so please check official ratings and warnings for your district at bom.gov.au, and have your plan ready before the afternoon peak.

[c02_mslp_fronts]

GUS Pressure is measured in hectopascals. A low means rising air and rain, a high means sinking air, usually clearer.

GUS This morning there's a low of 1005 hectopascals near Whyalla, and a weaker one, 1014 hectopascals, over the Coral Sea near Coffs Harbour.

GUS By tomorrow that low drifts into south west New South Wales and deepens slightly, while a high builds over the Great Australian Bight.

GUS High above it all, the jet stream, a fast ribbon of wind, is screaming along at about 273 kilometres an hour over inland southern Australia.

GUS That's genuinely something to picture, a ribbon of air moving faster than a Formula One car, stretched right across a wide swathe of inland Australia.

GUS That's the backdrop for tomorrow, some spin aloft, and warm moist air underneath along the New South Wales and Queensland coast.

[c05_dewpoint]

GUS Storms need moisture first, and the simplest way to feel that is the dew point, basically how muggy the air feels.

GUS Inland from Coffs Harbour, near Armidale, the dew point sits near 17 degrees, milder than the coast.

GUS Inland from the Sunshine Coast, near Gympie, it's muggier, dew point near 20 degrees, with about 44 millimetres of total moisture stacked in the air column, enough for very heavy rain if it comes down.

GUS So the fuel for heavy rain is there, especially in that zone behind the Sunshine Coast.

[c07_cape]

GUS Meteorologists measure the energy a storm can feed on. They call it CAPE. Think of it like the petrol in a storm's tank, in joules per kilogram.

GUS Near Armidale that tank sits around 2,500 joules per kilogram, a solid amount for this time of year.

GUS Near Gympie it's about 1,900 joules per kilogram, and out in the Gulf Country a much bigger 3,100 joules per kilogram, in country that's populated but remote.

GUS Energy alone doesn't make a storm, something still has to set it off.

[c08_skewt]

GUS This is a model sounding, a core sample through the air near Armidale.

GUS First, the cap. That's a layer of warm air above the ground acting like a lid on a pot, stopping bubbles of warm moist air rising into storms.

GUS Here the lid is barely there, just 1 to 2 joules per kilogram, essentially no lid at all.

GUS With a lid that weak, afternoon heating alone can probably get storms going without much extra help.

[c09_skewt]

GUS Same kind of picture, inland from the Sunshine Coast.

GUS The lid here is a bit stronger, around 20 to 28 joules per kilogram, still weak, but storms may hold off a little longer into the afternoon.

GUS Cloud base sits higher too, over 1,300 metres, against about 650 metres inland further south, usually meaning a drier layer near the surface.

[c11_shear]

GUS So why do storms love a weak lid and strong wind shear together? Here's the trick.

GUS A weak lid lets storms start easily, and shear, the change in wind with height, keeps storms organised instead of fizzling.

GUS Near Armidale that shear is about 71 kilometres an hour, near Gympie even stronger at about 80.

GUS Both are strong enough for organised storms that can start to spin, a supercell.

[c12_index_map]

GUS This index blends fuel and shear into one number, showing how favourable things are for a rotating storm.

GUS Across both inland zones the supercell value is high, favouring storms that organise and rotate.

GUS That's the environment, not a promise, it still depends on exactly where a storm fires up.

[c13_index_map]

GUS This hail index blends fuel, moisture and cold air aloft, judging how big hail could grow.

GUS That index is high enough for hail that could dent a car in one zone, more garden variety in the other.

GUS Hail's likely somewhere in these zones, bigger stones more likely further inland.

[c14_index_map]

GUS This last index looks at low level spin, key for a storm that could start to rotate.

GUS Both zones show modest spin, some low level spin possible, nothing extreme.

GUS There's also enough downdraft energy, called DCAPE, for a sharp gust front and damaging wind gusts.

[c94_sounding_compare]

GUS Here's a model sounding comparison, two columns of air, one inland in New South Wales, one in the Gulf Country near Normanton.

GUS The line on the right is air temperature, the line on the left is dew point. Where they sit close the air is nearly saturated, where they're far apart it's dry.

GUS At the New South Wales column that moist layer reaches up to about 400 hectopascals, roughly 7 kilometres up, a deep moist layer.

GUS At Normanton it only reaches about 600 hectopascals, shallower, so despite the huge fuel there, there's less moisture depth to wring out as heavy rain.

GUS These are model columns, not actual weather balloons, but a useful guide to each storm's rain potential.

[c19_model_compare]

GUS I check three models against each other for rain, the American GFS, the European model, and the European AI model.

GUS Near the inland storm zone in New South Wales they're a long way apart over the next two days, from about 3 to 17 millimetres, so they disagree a lot there.

GUS Near the Sunshine Coast hinterland it's similar, anywhere from about 6 to 34 millimetres.

GUS What they do agree on is storms are likely somewhere in these zones tomorrow afternoon. Exactly which town cops the heaviest fall is uncertain, so don't lock in a town yet.

[c10_sim_radar]

GUS Here's how tomorrow afternoon plays out, in order. Storms fire first inland, where warm moist air meets a change or a dry line, a boundary where moist and dry air meet.

GUS That inland zone sees the strongest storms, large hail, damaging wind and heavy rain all possible.

GUS Closer to the coast storms will be patchier, genuinely luck of the draw who gets rain and who misses out.

GUS Later in the evening those inland storms can clump into one bigger cluster, what forecasters call a mesoscale convective system, which can drift toward the coast overnight.

GUS Typical falls in the main storm band look like 10 to 40 millimetres, isolated pockets well over 100 millimetres under the heaviest cells, and plenty of places will see nothing.

GUS It's also build up season in the tropics, the trade winds that carried steady winter rain have swung round, leaving these hit and miss afternoon storms until the monsoon in December.

[c90_events]

GUS A quick look at events with real weather on the line.

GUS Sydney's Spring Carnival at Royal Randwick on Tuesday sits right under that storm risk, with about 4 millimetres forecast and an 80 per cent chance of a decent fall. Lightning means play stops.

GUS Sculpture by the Sea on the Bondi to Tamarama walk is on today, a huge crowd expected, with a 63 per cent chance of 5 millimetres or more, so pack something light.

GUS Newcastle's AFC Elite match Tuesday evening carries a smaller storm risk too, worth a glance at the sky.

GUS The Melbourne Cup on Tuesday at Flemington has an 88 per cent chance of a decent shower, storm risk itself low, so a brolly under the fascinator wouldn't go astray.

GUS Why did the racehorse pack a raincoat for the Cup? Because the going was described as soft, with a chance of wetter. Sorry, not sorry, back to the forecast.

[c21_town_table]

GUS Through the capitals now, each with today's high, tomorrow's overnight low and high, and the rain in millimetres.

GUS Sydney: a top of 25 degrees today, tomorrow low 19 degrees and high 27 degrees,

GUS half a millimetre of rain today and a patchy 5 millimetres tomorrow, umbrella handy given that storm risk near the carnival.

GUS That Sydney shower tomorrow is mainly an afternoon risk around Randwick, so if you're heading to the carnival take a small umbrella, elsewhere in the city it should stay fairly light.

GUS Melbourne: a top of 19 degrees today, tomorrow low 12 degrees and high near 19 degrees, barely any rain today but 15 millimetres tomorrow, Cup Day, so pack the brolly too.

GUS Most of that Melbourne rain falls through the day itself, so if you're at Flemington, the brolly under the fascinator and a bit of extra travel time wouldn't go astray.

GUS Both cities sit outside tomorrow's main storm zone, so think showers and a cooler change rather than anything severe.

[c21_town_table]

GUS Brisbane: a top near 31 degrees today with a shower around, tomorrow cooler, low 21 degrees and high 29 degrees,

GUS only a couple of millimetres in the city itself, the heavier stuff more likely in the hinterland.

GUS That couple of millimetres in Brisbane itself is nothing to change your plans for, just keep a light rain jacket handy if you're heading out towards the hinterland.

GUS Perth: a top of 21 degrees today, tomorrow low 16 degrees and high 21 degrees, both days basically dry. Perth's doing its usual thing, sunshine, and a bit of smugness.

GUS No rain plans needed in Perth either day, good washing weather if you've got a load waiting.

GUS Adelaide: a top of 23 degrees today with about 9 millimetres, that's the system we saw on the radar earlier, clearing by tomorrow to a low of 12 degrees and a high of 20 degrees.

GUS If you're in Adelaide, bring the washing in this morning, that 9 millimetres clears out well before tomorrow.

[c21_town_table]

GUS Canberra: a top of 22 degrees today and dry, tomorrow low 10 degrees and high 24 degrees with about 6 millimetres as that trough swings through.

GUS That Canberra shower tomorrow is a brief afternoon window, nothing to disrupt the school run or a barbecue earlier in the day.

GUS Hobart: a top of 17 degrees today, tomorrow low 11 degrees and high near 18 degrees, barely any rain either day. That's a proper jumper and cuppa sort of week down there.

[c21_town_table]

GUS Now the week ahead, from a European model's nine day outlook, a rain and temperature signal only, no thunder or hail information, so it says wet, not stormy.

GUS In south east Queensland, Tuesday is the wet day, Toowoomba wettest near 19 millimetres, with Brisbane, the Gold Coast, Sunshine Coast and Gympie all sharing in it, then quiet through midweek.

GUS Thursday and Saturday both carry plenty of stored storm energy again but nothing obvious to set it off, so I'd call those worth watching, not banking on.

GUS Central Queensland runs the same story most of the week, plenty of energy from Thursday to Saturday but no clear trigger, storms possible but could easily come to nothing.

GUS North Queensland looks similar, then Sunday carries an actual heavy rain signal centred on Mackay, with both models leaning wetter that day.

[c21_town_table]

GUS Northern New South Wales looks mostly quiet through the week, with Saturday the one day a trough arrives, though without much stored energy, so think showers, not storms.

GUS The Top End has the liveliest signal, with a heavy rain signal near Kununurra Friday, and huge stored energy over the weekend that the models can't agree on.

GUS South west Western Australia and Victoria and Tasmania both look quiet right through, nothing of note all week.

GUS For the weekend: south east Queensland looks quiet Friday, a storm chance that could fizzle Saturday, quiet again Sunday. Sydney mild and settled, Canberra dry, Melbourne quiet too.

GUS Days three and four of this outlook are a reasonable guide, by days six to eight it's just a signal that can flip in the next run, so hold it loosely, I'll update this afternoon.

GUS Why did the long range model refuse to commit to a forecast? It said it needed, and I quote, more time to think about it. Sorry, not sorry.

[c01_verification]

GUS Overall confidence in today's picture sits in a reasonably high band today.

GUS The soft spot is exactly where tomorrow's heaviest storms and rain land, especially around the Sunshine Coast hinterland, where the models spread out a long way.

GUS I'll flag it again this afternoon if that tightens up.

[c06_radar_now]

GUS One thing to watch for today if you're under catastrophic fire danger, a sudden smoky haze or a wind change can mean conditions are shifting fast.

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

GUS My next bulletin is this afternoon. If you've got a weather question, pop it in the comments and I'll get to as many as I can, and consider subscribing if you're new here.

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

GUS Look up now and then, the sky's the best show in town.

GUS Gus's Weather is a PandaVision production.