On Jul 2, 11:59*am, "Togless" wrote:
Looking north from my house here in Portsmouth I can see large grey clouds
looming up rather quickly, and on the satellite photos it has all developed
just in the last 2 hours or so - what is that called, when (presumably) the
heat of the sun makes the sky go from clear blue to masses of cloud in just
a couple of hours? *Anyway, I'm hoping that an onshore breeze will keep it
away from us here on the coast. *Sometimes being on the coast works in our
favour, and sometimes not (sea mist etc).

John.

It's convection over the heated land. The air will cool as it
rises and will form cloud when it reaches saturation. Today it won't
rise very far because there is warmer air aloft so the cloud spreads
out. We have similar cloud here.

Tudor Hughes, Warlingham, Surrey.