The sequence
A storm is a shape that changes. One volume gives you the shape. You need the run to see the change — and the change is the part that tells you what is about to happen on the ground.
The core falls
A loaded updraft holds its heaviest return aloft. When the updraft gives out, that core comes down. In a single scan it is a bright blob at altitude. Across five scans it is a downburst arriving.
A close three-dimensional view of one storm cell across several scans; the bright core at the top of the column sinks and the column loses its height.
The column dumps
Vertically integrated liquid climbs while a storm loads and falls away when it unloads. Everywhere else that is a number on a trend line. Here it is the column itself, thinning from the top down, while you turn it.
Two views of one storm cell fifteen minutes apart. In the first the column is tall with a high peak; in the second it is short and the peak has fallen.
Every 4 to 6 minutes
That is how long a WSR-88D takes to finish a precipitation-mode volume, and it is the fastest anyone gets this data. BeamWeather holds each scan, shows you when it was taken, and steps to the next. Ten scans is roughly the last hour.
And backwards
The same sequence plays over the archive. Pick a station, pick the evening it happened, and watch it again.