Southern and central England and most of Wales...

Weak mid-level instability will spread northwards across the Channel and through southern and central England and Wales during Thursday. Isolated to scattered showers and perhaps an odd thunderstorm are possible in this area. Lightning risk is considered low due to only modestly unstable mid-level profiles and lack of shear. 

Western Ireland and western Scotland...

Surface based thunderstorms may develop in response to daytime heating and weak surface convergence in these areas. CAPE values of 400-700 J/kg are forecast, however shear values remains low, therefore sustained updrafts are unlikely and lightning is considered a low risk.