Storm Forecast
Valid: Mon 19 Oct 2009 06:00 to Tue 20 Oct 2009 06:00 UTC
Issued: Sun 18 Oct 2009 19:52
Forecaster: DAHL

A level 1 was issued across Bulgaria, E Romania, Moldova, and central Ukraine mainly for excessive rainfall.

A level 1 was issued across the SW Balkan States mainly for severe wind gusts and marginally severe hail.

A level 1 was issued over the Tyrrhenian and Ionian Seas mainly for waterspouts.

SYNOPSIS

High-amplitude upper flow pattern exists over Europe, with an upper cut-off cyclone over Italy and the Adriatic Sea, which will slowly move into the Balkans on Monday. A strong Atlantic trough, with an attendant intense SFC low will reach the western parts of Europe late on Monday. Otherwise, a weakening high pressure area is present over central and E parts of Europe, and a large but weak LL cyclonic circulation is prevailing over the SE portions of Europe.

DISCUSSION

... Bulgaria ... E Romania ... Moldova ... central Ukraine ...

A plume of unstable air is present E of the Mediterranean upper low. Deep-layer and low-level shear will be sufficient for organized multicellular storms as well as mesocyclones, capable of large hail, excessive rain, damaging wind gusts and possibly a few tornadoes. Limiting factor is anticipated weak instability as well as a tendency for the convection to be elevated. It thus seems that LVL1 probabilities are sufficient, mainly for excessive rain.

... SW Balkans ...

Over the SW Balkans, some 30 m/s DLS and marginal CAPE should exist. Expect marginally severe hail/winds with the strongest cells in this regime.

... Tyrrhenian and Ionian Seas ...

Farther west, cellular convection over the Mediterranean Sea should persist in the deep polar air. Strong LL buoyancy suggests that a some waterspouts are possible, justifying a westward extension of the LVL1 area into the Tyrrhenian Sea.