Areas of heavy rain with embedded thunderstorms will move northwards during the early hours of Saturday, with torrential downpours in places. Accumulations of 20-40 mm are possible in 1 hour, and where heavy downpours persist then as much as 70-100 mm could accumulate in just a few hours. Significant impacts are possible if this occurs over more urban areas. The more widespread heavy rain should clear to the north during Saturday morning, but additional scattered heavy showers and a few thunderstorms could develop during Saturday afternoon and early evening, this risk covered by the much larger Yellow thunderstorm warning. For further details see https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings

Information on update: Warning area expanded westwards over northern England, and text updated. The start time has been adjusted to constrain the main risk period to Saturday, whilst the end time extended to later in the evening. Areas of heavy rain with embedded thunderstorms will move northwestwards across a large swathe of central and eastern England through Friday night into Saturday. Rain will likely be torrential in places, bringing 20-30 mm in less than an hour, with 60-90 mm in 2-3 hours possible in a few places. Whilst more widespread heavy rain will gradually clear northwestwards during Saturday, additional scattered heavy showers and thunderstorms may develop in its wake during Saturday afternoon and early evening, before eventually decaying later. For further details see https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings

Scattered heavy showers and a few thunderstorms will develop later on Friday evening, moving northwards from the English Channel into parts of southeast England. Whilst not all areas will see these during this period, there is scope for rainfall accumulations of 20-30 mm in some places by midnight, perhaps higher in isolated locations. More widespread heavy rain, torrential in places, is anticipated during the early hours of Saturday, covered by a separate warning. For further details see https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings