Mesoscale Discussion
Valid: Tue 12 Jun 2018 17:00 to Tue 12 Jun 2018 21:00 UTC
Issued: Tue 12 Jun 2018 17:14
Forecaster: PISTOTNIK

This Mesoscale Discussion is issued to highlight and imminent risk of widespread severe storms in SW Hungary and N Croatia.

A linear convective system is currently crossing SE Austria and with widespread damaging wind gusts. It will likely merge with further storms that have initiated to the south, over Slovenia and into N Croatia.
12z soundings from Rivolto, Zagreb, Szeged and Budapest confirmed CAPE on the order of 2000 to 3000 J/kg in this area, overlapping with deep-layer shear between 15 and 20 m/s. The environment has so far been untouched by convection over S Hungary, while outflows from previous (partly supercellular) storms from E Austria into central Hungary have cooled the low levels somewhat towards the north. The resulting axis of convergence roughly runs from Nagykanizsa to Paks at 17z and seems to be almost stationary. It is expected to be the focus for severe, possibly even extreme (>32 m/s) wind gusts as the convective line continues on its eastbound track.
In addition there is a risk of large to very large hail in case supercells are involved, either at the southern flank or ahead of this system. A tornado is not ruled if such a discrete storm interacts with the outflow boundary, where NE-erly flow and vorticity concentration might suffice for a spin-up.