The video clip seen above provides a good illustration of how the "chance of thunderstorms" weather forecast for the summer works.
The sky was pretty clear for a good part of the day.
Then the clouds rolled in, the thunder arrived, and the rain fell.
Rain continued to fall while the sky overhead of the shop was clear.
This storm hung around for a brief period of time before the blue sky returned. In Shop Foreman Brent's words, all it did was, "make the pavement mad."