Numerous showers are likely to develop on Friday morning across central and northern parts of the British Isles, the risk extending farther south during the afternoon and evening hours as stronger forcing associated with a shortwave slides SE-wards - across Northern Ireland during the morning, into Wales/Midlands during the afternoon and S / SE England during the evening.

While some isolated / sporadic lightning is possible virtually anywhere given the extensive coverage of showers and marginal instability, the risk of lightning is probably greatest in this zone from Northern Ireland through Wales / Midlands to S / SE England, given an overlap of stronger shear and better forcing allowing some cell organisation to occur. A low-end SLGT has been issued to highlight this potential, with extensions over the North Sea and English Channel where some lightning activity seems likely during the late afternoon / evening hours.

In general, profiles are more unstable but with weak shear in the north, and more capped but stronger shear farther south - somewhere in the middle, with an overlap of both shear and instability, would be favoured for the best lightning potential. The strongest cells may produce hail up to 1.5cm in diameter and wind gusts of 40-50mph locally.