Storm Forecast
Valid: Sat 23 Jun 2012 06:00 to Sun 24 Jun 2012 06:00 UTC
Issued: Sat 23 Jun 2012 11:28
Forecaster: VAN DER VELDE

A level 1 was issued for N Italy and central Balkan mainly for isolated large hail and severe wind gusts.

SYNOPSIS

A cold front extending from a low over the Baltic Sea extends southward into the Ukraine, curving back into the Balkan and Italy where it remains stationary. On the warm side of the front MLCAPE is predicted to assume value of 1000-2000 J/kg. Storms in northern Italy and the northwestern half of the Balkan will be under the influence of 10-20 m/s deep layer shear, most of it in the higher layers with quite weak shear below 3 km. Subsidence kicks in over western Italy while at best a very slight lift can be expected from the upper trough over the western Balkan.

DISCUSSION

...N Italy, W Balkan...

As low level shear from the surface is comparatively weak, confidence that cells easily assume supercell organization is not that high, despite good deep layer shear. However, local orography can cause more favorable backed surface winds, so some supercells will probably form, with large hail as main threat. Instability is rather high and evaporational cooling parameters look favorable for cold downdrafts, so that isolated severe wind gusts are not ruled out.

...Romania, N Bulgaria...

Presence of good shear in this region is marginal, but with high instability and quite good environment for evaporational cooling of downdrafts, some storms may produce large hail or severe wind gusts. Since lifting is poor, the level 1 here is quite marginal.