Storm Forecast
Valid: Thu 21 Mar 2013 06:00 to Fri 22 Mar 2013 06:00 UTC
Issued: Wed 20 Mar 2013 21:54
Forecaster: GATZEN

A level 1 was issued for northern and eastern Aegean and western Turkey mainly for excessive rain and severe wind gusts.

SYNOPSIS

Northern and central Europe is still affected by very cold and dry air masses. Across western Europe, a ridge builds during the period. Downstream, a digging short-wave trough affects the east Mediterranean. It is associated with a strong jet streak that leads to DCVA and synoptic lift. Late in the period, the cold front of an intense Atlantic low pressure system reaches western Europe.

DISCUSSION

Southern Italy to Greece and western Turkey

A strongly-forced synoptic situation is expected for south-east Europe. An amplifying short-wave trough will rapidly move south-eastwards and leads to strong DCVA and associated synoptic lift. This will cause rather steep mid-level lapse rates that will overlap with rich boundary-layer moisture that builds below the warm subtropical air mass ahead of the approaching trough. Latest GFS indicates CAPE up to 1000 J/kg.

Low-level forcing is expected due to convergent flow below the trough centre rather than along the cold front that seems to be relatively poorly organized. Therefore, thunderstorm clusters are expected that may organize into multicells late in the day given strong deep layer vertical wind shear that develops across the east Aegean and western Turkey. Storms that form will have a potential of producing excessive rain especially along the coasts/mountains with upslope flow. This threat increases during the period across western Turkey where a level 1 is warranted. Additionally, severe wind gusts are possible given the high background wind field in the same region from the Aegean Sea to western Turkey.