The main interest begins close to midnight Saturday night, in association with a rapidly deepening surface low that will be approaching the Outer Hebrides at this time. Under the influence of the left exit of the mid-level jet and tropopause fold, very dry mid/upper-level air will overspread a very moist low-level airmass, creating substantial potential instability. Given the very strong forcing aloft, some embedded convection could develop in the vicinity of the southern Outer Hebrides, this would then drift quickly eastwards across the Inner Hebrides and then northeast across the mainland from western to northeast Scotland during the early hours of Sunday. Forecast profiles suggest such convection would be elevated above the 750-800mb layer, perhaps aided by a strong low-level jet. The exact west-east corridor, and also the extent of lightning (if any) is a little uncertain - primarily due to the exact track of the surface low - but should confidence improve then a SLGT may be considered.