Ninety particles thrown from the centre every two and a half seconds, under gravity and drag.

Each burst seeds ninety particles at the centre with a random bearing and a speed between eighty and two hundred and sixty. They integrate under a constant downward acceleration with a per-frame drag of 0.985, so the spray arcs rather than travelling straight, and every particle carries its own radius and a life that decays independently — the cloud thins from its edges rather than vanishing at once. Alpha is the life term, so a particle fades exactly as it dies. Colour is drawn per particle from a five-stop palette, which is what stops the burst reading as one solid mass.