Der zweite 3er in diesem Jahr heuteAlpine region, Pannonian Plain, and the northwestern, western and central Balkans...
NWP models suggest that on Wednesday morning scattered rapidly-moving elevated storms may be ongoing across the large level 2 area. Forecasting their locations and intensity is very difficult even 6 to 8 hours ahead. Although these storms pose some risk of severe winds and large hail, their elevated nature limits this risk, and stronger storms are expected to develop later in the day.
During the afternoon, as the aforementioned vorticity maximum approaches the Alps from the west, per all NWP guidance, widespread initiation is expected across the southern and central Alps. The storms will do so in a very unstable and strongly sheared environment, so that rapid evolution into supercells, followed by a transition to one or more bow echoes is expected. Additional storms could form across the Dinaric Alps, and possibly across the Po Valley as parcels are lifted ahead of outflow boundaries from the Alps.
The very high instability and strong storm-relative low-level wind in this environment suggest that some storms will likely produce very large hail in the 5-10 cm range. The transition in a bow echo is expected during the evening as the storms move across the northwestern Balkans, and possibly Hungary. Widespread severe winds are expected as a result, including some extremely severe winds of more than 32 m/s. Overnight, the system should very gradually diminish in intensity as an environment with lower CAPE is encountered across southern Serbia, Romania, and Bulgaria.
Chasingteam Südost in Bereitschaft (Bericht von gestern folgt)
LG, Harald
