Just on another note why was Monday so Severe .

Why those winds lasted so long

1. True mesocyclone structure formed
Monday’s storms weren’t ordinary multicells — several had well-defined mesocyclonic rotation.
Rotation does two things:
Increases the storm’s lifespan, often from 15–20 minutes (pulse storms) to 45–90 minutes (supercells).
Sustains the downdraft and rear-flank downdraft (RFD), which is what produces strong, persistent winds at the surface.

A rotating storm won’t collapse quickly — it keeps recycling and feeding itself.
This is why the winds didn’t spike for 2–3 minutes and ease. They remained steady and destructive.

2. RFD jets were unusually strong
We experienced the primary RFD surge, followed by a secondary RFD pulse.
In many supercells, those two merge into what feels like a continuous gale.
When the RFD mixes down dry mid-level air with momentum, it turns the downdraft into a sustained horizontal wind event, not a short burst.
People compare this to cyclonic winds because:
The duration and consistency are similar
The sound is different (lower, steadier, like a freight train)
Trees and structures fail from prolonged loading, not just gusts
The long Sustained winds of 90–140+km/h is absolutely consistent with a deep RFD jet in a sustained mesocyclone.

3. The storm transitioned toward an MCV / mesoscale vortex
The satellite images I posted before the storms hit on Monday over SEQ showed a developed mesoscale convective vortex (MCV) — basically a small, warm-core low that can form inside a long-lived thunderstorm cluster.
On satellite, these look like:
a broad, circular rotation
dense overcast
a “centre” where cloud bands wrap slightly
That’s why it looked like a low-pressure system sitting over Brisbane — because in a sense, it was.
This structure dramatically increases:
storm duration,
wind persistence,
rain wrapping, and
embedded rotation pockets.

4. Extremely high PWV + strong instability = huge cold pools
PW values around 50–55 mm and CAPE > 2,500 J/kg mean enormous precipitation loading.
When the downdraft punches down:
more rain mass = more downward momentum
more melting hail = cooler, denser descending air
deeper cold pool = stronger and longer outflow winds
That’s why hail and wind damage were both extreme and widespread rather than isolated.