VALID FOR 30-07-2014
*** A severe weather outbreak appears likely across the Adriatic sea and surropunding areas. Starting in early morning from the north and spreading south during the day. All types of severe events are possible – the main threat is locally very heavy / excessive rainfall. ***
A powerful upper low will be moving across the central Mediterranean and serve as a focus for robust severe weather episodes. Another trough will be pushed east across the NW Europe with an associated frontal boundary from CNTRL Scandinavia into central Europe. A short-wave moves from E Scandinavia into NW Russia.
A HIGH risk has been issued for coastal areas of Adriatic sea inland into western Balkans and into parts of N Italy with threat for torrential excessive rainfall, tornadoes / waterspouts and lesser extent for severe winds and large hail. It appears likely that a severe weather outbreak will occur on Wednesday and locally dangerous flooding conditions are expected. As the upper low makes progress further SE into central Mediterranean, widespread storms and clusters should develop / maintain along the SE-wards moving cold front across E Adriatic sea onshore onto the Dynaric mountain range. Strong QG forcing combined with extremely unstable airmass and moderatelly strong deep layer shear / helicity within persisting strong southerly LL jet should result in organized severe storms where serious flash floods risk will exist due to combined strong orographic and convective rainfall. Very high amounts of rainfall (100-150mm/24h) locally are well possible. Further north towards N Italy, a stalled frontal boundary should act as a trigger of persisting maintaining cluster abd therefore high amount of rainfall is expected as well.
A MDT risk has been isued for areas surrounding the HIGH risk area where excessive rainfall threat is expected, but more isolated and less severe in nature. Besides excessive rainfall threat, large hail, severe winds and some tornado threat will exist where more discrete supercell storms could form.
A MDT risk has been issued for E Germany, Czech Republic, W Poland into Baltic sea and SE Sweden with threat for excessive rainfall. An eastwards progressing slow moving frontal boundary should result in widespread mostly multicell storms in strongly unstable but weakly sheared environment.
A broad SLGT risk area has been issued for surrounding areas of HIGH/MDT risks where isolated severe storms are possible, bringing threat for excessive rain and some severe winds or large hail threat.
A SLGT risk has been issued for parts of Scandinavia into NW Russia for excessive rainfall, large hail and severe winds.
A SLGT risk has been issued for extreme NE Turkey, Georgia into SW Russia where potential for some isolated storms with large hail / severe winds threat will be enhanced.