A cool rainy day is in store for us in parts of the South East today. BOM is forecasting a maximum of 21°C for Brisbane and a 95% chance of up to 35mm of rain. The rest of the week has showers predicted.


The Mt Stapylton 128km radar image from 7.35am today:





The BOM Brisbane forecast for the rest of the week:

Wednesday 10 September, there is a chance of a storm in the central Southern Interior of Queensland this afternoon. Most of it will loose its strength before moving into the South East corner of Queensland, but there is a chance that storms will continue over the border as the trough moves to the East. It has very low values in the storm at this point.

As for South East Queensland, we should expect showers to develop this afternoon and “ if” there is any cape still around along with other variables we may get the odd thunder clap in those showers. But that is a big IF and May. The atmosphere is not primed to support big storm activity at this point in time. (But we know that freak things do happen when the weather warms up. )

Still not a great deal showing up at this stage with regards to storm activity for our region. After this trough moves out, the only colour showing up is next Wednesday, but it is not hinting towards storm activity at this stage.

So after a warm to hot day, today, the weather will cool down slightly once again with cloudy days and the odd shower about.

Here is the chart for 13:00 this afternoon. Very weak values in the atmosphere but it will be worth having a looking at the Soundings for Moree etc, once they come out this morning.

Waiting for photo to upload.

Edited by user Thursday, 11 September 2025 7:37:47 AM(UTC)  | Reason: Not specified

As per my post the other day, we are at the beginning of storm season and given the right atmospheric conditions, storms could pop up although the modelling may have missed it. This seems to be the case this afternoon. A couple of small cells have developed and can be seen on the radar. They are not big storms or throwing out a lot of lightning but a few strikes have been detected.





Looking at the sounding this morning and you can see a small amount of cape ( instability), just enough to allow some small cells to develop.
Fortunately, given the mid and upper level temperatures, and not a lot of shear ( updrafts ),it was not a big storm day otherwise large hail would have been a big problem.

Some storms have fired of this afternoon as per the gfs stormcast.

I was watching the cell around Millmerran and for a couple of sweeps of the radar, a small black core was visible with a slight rotation. Nothing too big. But Northern NSW is getting the better of the storms.

Below is the Toowoomba Radar with a small black core close to Millmerran .



The lightning trackers have been busy especially over the border in the Northern areas of NSW. At this stage it really is a wait and see if storms can make it all the way to the Coast for the SEQLD. The Sounding this morning from the Brisbane Airport was pretty much in line with the modelling forecast from last night. There was a big inversion at 900 -650mb on the sounding which would have made storms very hard to develop. There has been no balloons released this afternoon at this stage, to see if that Inversion is still there or even if there is a bit more moisture in the lower levels. It was a bit scarce this morning as well.



Lightning trackers.

Edited by user Friday, 19 September 2025 4:40:43 PM(UTC)  | Reason: Not specified

GFS has absolutely being nailing the Storm probabilities with its modelling system incredibly well. For the last 3 days it was going for storms on Northern tip of the Sunshine Coast right up into the Wide Bay Region.

A severe storm warning has been issued as per below along with the radar sweep and GFS stormcast.

The run of hot and dry days continue within the areas of this thread. Wednesday still looks to be a bit of a storm day for us but more of a dry storm. With the dry fuel on the ground from all the growth we had during those wet periods, one good lightning strike could set off bushfires.

The storm for tomorrow and maybe Thursday has changed considerably since I had 1st mentioned it a few days back. The storm chokes itself at 24,000 feet ( approx), there is moisture above that height, but it has to try and fall to the ground through a dry and hot environment.

Below is the storm cast for Wednesday . The other thing to consider is some of the models only have the storm making it to the range and not to the Coast, but that can change if we get enough of a NE wind came in off the Bay and Sea.



The original sounding from the model shows the moisture trapped above at 24,000 feet and the dry slot below. There is also a strong cap in place. Just really need to see tomorrow’s Sounding in real time to get a more accurate picture.



If it heats up slightly quicker by a few degrees and the dew point could reach 20°C ( which maybe hard due to the dry air) we could see the cap broken but we still have the moisture way above us and not a great deal in the lower levels.

The new plotted sounding.



It really is a wait and see what eventuates. There is a lot of cape, instability etc sitting out in the ocean but just not enough inland at this stage. The best thing is to keep an eye to the sky and an ear for any warnings if storms do get going. Also if you are in a bushfire prone area, it would be wise to have your fire plan in order and bug out bags ready just in case. This is not to scare but just being realistic. And please note, these are my simplified take on the models and should not be treated as warnings or accurate. Things do change quickly. I try and simplify weather as much as I possibly can. Weather should be in a way that everybody can understand!

Edited by user Tuesday, 30 September 2025 8:35:21 AM(UTC)  | Reason: Not specified

There s still a low chance or a thunderstorm today and on Thursday. But it really is a wait and see as real time data is released. Each run diminishes the chance of decent rain and having enough energy and instability in the atmosphere.

We were expecting to have a wet spring but that has been turned on its head for the time being due to the hot air above the Antarctic. It had a 30-35°C increase over the last few weeks which has thrown the other weather drivers out of the picture to a very high degree. In time this SSW will fade will cool and maybe the El Niño will once again return as the main driver as previously forecasted to do so. Once again we will have to see the full effect of the SSW and what will then become the dominant weather drivers for the rest of Spring/Summer.

Below is an extract from the ABC in regards to the SSW.

The temperature high above Antarctica has climbed more than 30 degrees Celsius in the past week.

This is known as Sudden Stratospheric Warming (SSW), an event that has the potential to disrupt weather patterns across Australia for months.

SSWs are extremely rare in the Southern Hemisphere, with only two major events documented in the past 60 years — one in 2002 and the other in 2019 — and both resulted in some of the most devastating bushfires in Australia's history.

While a wetter background environment should prevent a repeat of Black Summer in 2025, the warming has thrown a major spanner in the works of the spring forecast — a shift already being felt throughout the country, including the current run of unseasonable heat along the east coast.

The full article can be found here.

https://www.abc.net.au/n...lia-for-months/105817572

Thank you Colmait for keeping us updated with these changing weather conditions.

Having similar conditions to 2002 and 2019 is a bit scary as far as bushfires go. The ground is getting very dry and cracks are appearing already and the potential for dangerous bushfires is very real. For example, a local rural fire brigade that have attended many fires over the last week, posted yesterday that grass fires are running extremely fast and dangerous at the moment. On Monday the Qld Fire Service issued a Leave Immediately alert for resident of Mt Nebo Road Enoggera Reservoir due to a potentially life threatening bushfire. So as you mentioned Colmait, having a bushfire plan in place is really important during these conditions.

This is the forecast for the Brisbane area for the next few days. Thursday will be quite warm with an expected maximum of 34°C then some cooler temperatures later in the week.

Friday Convective Outlook – SEQ & Northern NSW (GFS vs EC) 13:00 AEST

The latest model runs this morning are showing some disagreement for Friday’s potential storm setup across South-East Queensland and Northern NSW. Here’s what the data currently shows. What I have done is put a simplified technical post followed by my simple version.

1. Model Overview

- GFS has backtracked on earlier stronger convective signals. It’s now showing a dry mid-level profile with limited instability — only weak inland convection possible.
- EC remains slightly more bullish, hinting at isolated storms Friday and potentially ramping up instability through the weekend, especially Saturday–Sunday, as deeper moisture returns.

Simple version:
GFS has pulled back on storms for Friday, while the European model (EC) still thinks a few might develop and become more active over the weekend.

2. Sounding Analysis – Friday 13:00 AEST



Brisbane

- CAPE: ~1 J/kg (essentially nil)
- CIN: ~340 J/kg (strong cap)
- Profile: Pronounced dry slot between 700–500 mb, no meaningful instability or lift.
- Outcome: Capped, stable atmosphere.
Plain-English: Air is too dry and stable — no storms expected near the coast.

Toowoomba



- CAPE: ~186 J/kg
- CIN: ~83 J/kg
- LCL: ~740 mb – high-based
- PW: 33 mm – slightly better moisture than coast
- Profile: Still quite dry aloft, weak instability, minimal shear support.
- Outcome: Small window for isolated high-based convection late afternoon if surface heating is strong enough.
Plain-English: Toowoomba has a tiny chance of a dry, gusty shower or weak storm — but it’s a long shot.

Dalby



- CAPE: ~365 J/kg
- CIN: ~88 J/kg
- LCL: ~754 mb
- PW: 33 mm
- Profile: Similar dry layer mid-levels but marginally better instability inland.
- Outcome: Slightly more favourable for an isolated, short-lived storm.
Plain-English: Inland near Dalby could see a weak storm if conditions line up — 20–30% chance, mainly late afternoon.

3. Pattern

There’s a clear dry intrusion in the mid-levels cutting off deeper convection across SEQ.
The cap is strong east of the ranges, so updrafts will struggle to initiate.
Even if convection fires inland, the high LCLs suggest any storms will be high-based and short-lived, possibly producing dry lightning or gusty outflows rather than heavy rain.

Simple version:
The air higher up is too dry for healthy storms. Even if a few form inland, they’ll probably collapse quickly with gusty winds and little rain.

4. EC Comparison (Weekend Outlook)

- EC continues to signal moisture recovery and increased instability Saturday–Sunday, especially over the Darling Downs and Scenic Rim, with some potential for stronger or even severe storms by Sunday if surface dew points rebound.
- GFS lags this trend, still keeping dry mid-levels into Monday.

Simple version:
If EC is right, we’ll go from dry and stable Friday to much better storm potential over the weekend. GFS is slower to bring that change.

5. Summary / Probabilities


Friday looks mostly quiet storm-wise under GFS guidance — maybe a few high-based cells inland if heating pushes through the cap.
EC hints that things could change quickly into the weekend with deeper moisture returning, so it’s worth keeping an eye on updates over the next two runs.

So basically in a nutshell, Friday is likely too dry for decent storms around Brisbane. Toowoomba and Dalby have a small chance of weak, dry ones. The better storm days could be Saturday or Sunday if the European model is right and moisture returns

So it is really a wait and see how the next couple of runs goes — this setup could still swing either way if the moisture returns.

Fire Weather Note:

While a few high-based or dry storms could develop inland on Friday, these types of storms are unlikely to bring meaningful rainfall. Instead, they can produce dry lightning and gusty, erratic winds — both of which can easily trigger or spread bushfires under current dry conditions. If you’re in or near active fire zones, keep an eye on local warnings and be aware that these storms can look promising on radar but deliver little or no rain to the surface.

As I said earlier, EC, over the week end did look a bit more generous but it is a wait and see.

Cheers.

Colin