Mesoscale Discussion
Valid: Wed 14 Jun 2017 10:00 to Wed 14 Jun 2017 18:00 UTC
Issued: Wed 14 Jun 2017 10:01
Forecaster: PUCIK

... E France ...

Satellite imagery reveals spiralling cloudiness, associated with the mid-tropospheric trough, slowly advancing over SW parts of France. Embedded showers and weak, elevated thunderstorms are apparent from the radar and lightning detection data. Towards the east, Cu fields are forming as the daytime heating progresses over the Massif Central. Surface observations confirm the presence of moist lower tropospheric airmass, which will be supportive of moderate to high CAPE values.

In contrast to the model output from yesterday, in reality very little convective debris has been left from the previous night convection and thus, environment seems to be primed for higher coverage of severe weather than formerly expected. In the next few hours, surface based initiation is forecast over the area of interest, with well organized convection thanks to the DLS at or above 15 m/s. Very large hail may occur with transient supercells. Storms may cluster later on (as simulated by some high resolution model output) and form a common cold pool, advancing towards the W Alps in the afternoon with the threat of severe wind gusts.