Marginal day for parts of Europe tomorrow with a Hail and Tornado Threat for far South Russia and Eastern Turkey .
As 2 cold front push through Eastern Europe, they each cause upper troughs, one situated down Poland into Hungary and the other down in far South Russia. First we will discuss Poland, Lithuania and Hungary. As this trough forms SBCAPE values are at 1,000-1,5000 j/kg with dew points at 15C-17C so there is good moisture, Potential updrafts do seem weak for a strong hail forecast but there is a potential for pea size hail and if updrafts do remain potent but not strong with the chance of Excessive Precipitation you could see hail storms develop within the marginal regions. Localized flooding is a low threat for tomorrow.
With the upper trough ahead of the cold front situated over South Russia, SBCAPE values will range from 1,000-1,700 j/kg with dew points at 17C, updrafts are potentially strong for these storms tomorrow with a slight chance of moderate-large hail forming within these storms. PWAT values look reasonably strong so the thunderstorms have a chance of being outflow dominant (High Precipitation) causing surface flooding with a chance of localized flooding. There is also a tornado threat with these with the chance of low-level mesocyclones to form. 0-1km Shear is very weak with spots of 15kts and SRH 0-3km values are moderate at 200m2s2.
A marginal has been issued for North Spain and the Pyrenees for the evening where SBCAPE values could get as strong as 1,500 j/kg with the chance for potent updrafts for a low hail threat but also the chance of excessive precipitation.