Western and northern France towards the Channel and SE England
Ahead of the approaching long-wave trough, warm air advection has set in, and a plume of elevated steep lapse rates has reached southern Iberia. Today, string low-level heating will cause rapidly improving lapse rates over Spain that spread into France as well. At low levels, moisture increases over France and the Channel region, resulting in MLCAPE in the order of 1000 J/kg.
Convection initiation is questionable over most places due to weak lift. Best potential exists along the nose of the warm air that affects the Channel region in the late afternoon and evening. Storms form in moderate to strong deep layer vertical wind shear with increasing south-westerly mid-level flow, and multicells and supercells are forecast, capable of producing large hail and severe gusts.
Due to strong 0-3 km shear and strong lift, storms are forecast to organize into an MCS that travels east along the warm front, capable of producing severe wind gusts and heavy rain. This activity can also affect SE England during the night. While the storms turn elevated, they move farther into the North Sea until the morning.
Along the southern flank of the cluster, scattered storms will form across France along the outflow boundary. CAPE-shear overlap seems to be sufficient for some stronger multicells, and severe wind gusts and large hail are still possible during the night.
