VALID FOR 29-06-2014
*** A severe weather outbreak appears likely across parts of the N Mediterranean on Sunday. Very large hail, tornadoes and flash floods are increasingly likely to occur. ***
A robust weather scenario is shaping up for central Europe on Sunday. A prolific setup with a deep negatively-tilted trough and sharp cold front is being pushed from W into CNTRL Europe. Strongly unstable airmass is placed across the northern Meditteranean while an unusually strong mid-level jet with strong shear overspreads the region. Strong QG forcing should result in widespread organized storms within the left-exit jet region. Another short-wave trough moves across the Black sea and Turkey.
A HIGH risk has been issued for N-NE Italy, N Adriatic, extreme W Slovenia and extreme NW Croatia for large hail to very large hail, torrential excessive rainfall, severe wind gusts and tornadoes. Conditions are coming together for a severe weather outbreak along the southern Alpine flank starting by early afternoon over NW Italy and spreading east during the late afternoon and evening hours. Very strong instability and shear, combined with a strongly helical environment suggest that supercells will be the dominant storm mode, with a significant fraction being potentially tornadic. A strong tornado is quite possible. Storms should grow upscale into large cluster or two in the evening hours while spreading into N Adriatic and Slovenia. Persisting SW flow onto the complex Alpine terrain should lead into excessive rainfall amounts, locally in excess of 100mm / 24hrs especially along the southern Alpine flank into NW Slovenia.
A MDT+ risk has been issued over areas surrounding the HIGH risk for N Italy, SW France, parts of Switzerland and Austria for large to very large hail, heavy rainfall, severe wind gusts and some tornado threat over N Italian plains. Less coverage of severe storms is expected.
A SLGT/SLGT+ risk for the surrounding areas of HIGH/MDT+ risk for large hail, heavy rainfall and severe wind gusts. Additionally, some tornado threat seems possible over the coastal areas of Liguria and Tuscany where strong LL shear / helicity is expected.
A SLGT risk has been issued for N Tunisia and NE Algeria for large hail and severe wind gusts.
A SLGT risk has been issued for E Turkey and Georgia for large hail, severe wind gusts and heavy rainfall.