Storm Forecast
Valid: Mon 15 May 2017 06:00 to Tue 16 May 2017 06:00 UTC
Issued: Mon 15 May 2017 02:38
Forecaster: VAN DER VELDE

A level 1 was issued for parts of Poland, Slovakia, Hungary, Austria and Croatia and central Italy mainly for excessive convective precipitation.

SYNOPSIS

The remains of an upper trough are over central Europe with a N-S elongated PV band moving slowly eastward over eastern Germany, into an unstable stagnant air mass (200-800 J/kg MLCAPE). A warm front followed by very moist air, controlled by an active Atlantic low, makes its way into Ireland and UK and into western fringes of the surface high over western Europe. Another low affects western parts of Russia and the Baltic countries, where a plume of warm unstable air extended from central Europe will produce thunderstorms.

DISCUSSION

...central Europe...

A level 1 was issued for a band between Poland and Croatia, where low-level convergence in models and very slow storm motion vectors combine. This could here and there result in storms persisting in one location, with potentially excessive rain as result. The weak shear generally does not suggest long convective life times, but regeneration by the convergence zones augments the threat. Note that these conditions also benefit spout-type tornadoes.