Mesoscale Discussion
Valid: Wed 21 May 2014 18:00 to Wed 21 May 2014 21:00 UTC
Issued: Wed 21 May 2014 18:05
Forecaster: GROENEMEIJER

Ahead of an intense mid/upper-level trough, scattered convective activity has developed, including a few stronger storms. These stronger storms occur along a NNE-SSW oriented boundary along which mass convergence is taking place.

The environment is characterized by very strong (30-35 m/s) deep-layer and low-level (10-20 m/s) shear, and marginal MLCAPE (500 - 1000 J/kg) close to the boundary.

As the through moves northward, the focus of the convection will move northward as well. A weakening linear system is moving northward across the northern half of the indicated area and may still produce isolated strong to possibly severe wind gusts. There is a small possibility that one or two (possibly embedded) supercells can develop despite the marginal instability. If that occurs, a tornado threat is present given the strong low level shear with long curved hodographs.

Further south, clustered convection is occurring, with a recent supercell storm near Brive-la-Gaillarde now decaying. This activity is expected to gradually weaken in the wake of the upper-level trough.