Numerous scattered showers and thunderstorms are expected to develop fairly widely. Across England, Wales and the Republic of Ireland these will tend to be organised into distinct SW-NE lines along zones of low-level wind convergence, and so areas either side of these lines will have a relative minima in activity. The position of these lines will tend to drift gradually eastwards with each hour.

On the forward side of the upper low, the environment will be reasonably sheared, aiding cell organisation such that individual showers/storms may last some time and track a fair distance given the strong steering flow. This means that rainfall totals will generally not be too problematic from an individual shower/storm, but shower training over similar areas may occur - although as mentioned, as the shower lines drift slowly eastwards, this may also not be too much of an issue. An isolated supercell may be possible, and there could be some notably gusty winds around some of these showers/storms - an isolated tornado is also not ruled out. Hail up to 2.0cm in diameter will be possible from the best-organised cells. The short land track over SE England suggests very little showers will affect these areas.

With greater proximity to the upper low, the slack flow across Scotland, and to a certain extent Northern Ireland, will result in slower storm motion and a greater risk of localised flooding given prolonged downpours. One or two spout-type funnels / weak tornadoes may be possible where low-level vorticity gets stretched upwards by updrafts.

Lightning activity will generally decrease by mid-late evening as daytime heating subsides, but the risk (albeit lower) persists overnight in exposed western parts - particularly NW England.