The warning for North West England is of: "Heavy showers and thunderstorms leading to a chance of flooding and disruption".
In more detail, it states: "Heavy showers and thunderstorms are expected to break out from late morning on Sunday, perhaps becoming quite widespread during the afternoon. Some places will miss the worst of these, but where they do occur, 20 to 30 mm rain could fall in a short space of time leading to some surface water flooding. Lightning and hail will be additional hazards. Showers and thunderstorms will only slowly ease during the evening and some could persist well into the night."
The warning is for between 10am and midnight tomorrow.