Went out and chased this one in south Essex. Saw impressive distant lightning around 22z whilst walking the dogs and then checked radar. Impressive cgs seen around East Hanningfield, South Woodham Ferrers around 2330z. Drove directly under one cell in Torrential rain in Bicknacre, roads instantly flooded, then north to Maldon where dry. Continued to skirt round north of cell in dry area near Burnham before heading back to Southend where more impressive cgs observed. Most unexpected!