wrote:
How come this time there are no thunderstorms? Usually when the air changes
from hot air to cold air there are?

http://www.metcheck.com/V40/UK/HOME/



Not being a physicist, I can't comment on the dynamics, but my anecdotal
experience is that when the cooler air arrives behind a front moving
north to south, it doesn't involve any atmospheric hijinks. When it
arrives behind a front moving south to north, then it goes bang.

I can remember driving home from London one July day when it had been
widely 30+c across SE England. By the time I got home (near Swaffham,
Norfolk) it was grey and misty with a temperature of about 13c. No rain,
no thunder, nothing.

It happens.

--------
Chris
Swaffham, Norfolk