Charts still showing an upper trough becoming slow moving to the west of
Britain and later tending to migrate over UK with further troughs digging
down to the west. No good looking at the surface patterns as they are slack
and it is the upper air which will drive events anyway. The fronts coming in
later this weekend/Monday will leave a residue of high theta-w air at the
surface priming the atmosphere for instability which will be released as
vorticity advection provides ascent at mid-levels. Who will get the best
storms is open to debate and that detail will have to wait nearer the time
but generally becoming cyclonic and still rather warm with thundery
downpours likely. Could be the best spell of the summer so far for
thunderstorms!

-----------------------------------------------------------
Will (Haytor, Devon, 1017 feet asl)
-----------------------------------------------------------