Nord-Italien, Slowenien, Ungarn, Süd-Ost Österreich und Kroatien
The interaction of the cold front with the Alps creates a front with split-flow characteristics due to blocking of the LL flow. A belt of 500 to 800 J/kg MLCAPE evolves from N-Italy to Hungary. The cold front should start to push to the SE during the afternoon and early evening hours. Scattered deep updrafts evolve along the cold front and take advantage of 25-30 m/s 0-6 km bulk shear. CAPE/shear overlap indicates a good chance for organized multicells/isolated supercells with large hail and severe wind gusts. Confidence in initiation over N-Italy decreases from E to W as we move deeper beneath the anticyclonically sheared side of the mid/upper jet.
Upward motion associated with upper-level divergence will take place near the front along/south of the Alps. It will aid the development of a line of storms over SE Austria, that quickly moves to the southeast across E Slovenia, E Croatia and Hungary. 25-30 m/s winds at 850 hPa should mix down to the surface, so a concentrated swath of severe wind gusts could evolve. Any more discrete storm structure continues to pose a large hail risk. Although LL shear will be enhanced along the front, marginal LLCAPE/LL lapse rates should keep the tornado risk on the lower-end side. Also, strong CAA could help to undercut updrafts rather fast. Still, with shear seen in forecast soundings, an isolated tornado risk can't be ruled out. Beyond sunset, the main risk with those storms will be gusty winds/isolated severe wind gusts and marginal hail.
Isolated thunderstorms continue over the N-Adriatic Sea, N-Italy and the W-/CNTRL Alps all night long. Limited CAPE precludes organized/long-lived convection although isolated large hail and strong wind gusts remain possible...especially in case updrafts grow deep enough to take profit of 30 m/s DLS (e.g. N-Adriatic Sea).
[x] 8072 Fernitz bei Graz (Südsteiermark)
Es blitzt, es rotiert & es ist dunkel also jage es :D