Thunderstorms and heavy showers have been predicted to break out in Lincoln this morning and afternoon, with the possibility of localised flooding and disruption to travel.
The Met Office has issued a weather warning for Friday, July 22, which is valid from 11.10am until 10pm.
Some of the showers will be slow-moving, leading to prolonged thundery downpours.
The torrential rain could see up to 20-25 mm fall in a short space of time and in excess of 50 mm in two or three hours.
Forecasters have said that the heaviest showers are likely during the afternoon and early evening, coinciding with the rush hour.