On Jul 16, 8:57*am, "Col" wrote:
In just a couple of hours, the rain band has developed from something
pretty light and fragmented into a far larger and intense area of rain.
What makes this happen so quickly, it was certainly well forecast.
--
Col

Bolton, Lancashire
160m asl

Presumably it is due to the air rising as it passes over land. In
other words it it is the vertical movement not the related horizontal
movement.

Cheers, Alastair.