11pm Sun
Moderate Risk of Thunderstorms N.Wales & Northern UK 15Z-21Z
Prime Risk Large Hail & CG's
Slight Risk of Tornado Development 15Z-18Z as per red box
Currently some broad variation within the models ATM. Though for me based on the GFS I see a prime region for strong convection as per map below. In fact based on the overlay of strong CAPE values to vertical shear we will have the basis for supercell development. I am further encouraged by a very dry incursion within the mid levels which is likely to increase lapse rates quite dramatically. As Chris mentioned, vertical shear should sustain an isolated storm long enough for large hail to build within the updraft. Some strong convective gusts are possible though likely to be non severe!
My attention is primarily drawn to a small zone where low level direction shear turns a full 90 deg (red box). The convergence closer to the coast could well trigger a tornado or two. Winds above 850 mb look fairly straight lined so not sure if any mesocyclone development will extend upwards into the mid level efficiently.
The larger picture may well see some minor convective storms develop across other parts of the UK though dynamic lift looks rather weak for anything substantial. Hence my focus within the convective box below!
CREDIT: Tony Gilbert
