UK weather: Met Office issues thunderstorm warning as 50mm of rain set to hit parts of BritainA major change is under way after days of intense heat, but the weather will not become calmer everywhere. An area of low pressure will become centred over Scotland during Tuesday afternoon, bringing increasingly unsettled conditions to northern and western parts of the UK. Where the heaviest rain will fallThe Met Office has issued a yellow weather warning covering Northern Ireland and parts of southern and eastern Scotland during Tuesday afternoon and evening. Farther south, scattered showers are expected across Wales, south-west England and northern England, although many places will remain dry. Elsewhere, Northern Ireland, northern England and Wales can expect a mixture of sunshine and scattered showers, while much of southern and central England should remain dry.