Storm Forecast
Valid: Thu 17 Oct 2013 06:00 to Fri 18 Oct 2013 06:00 UTC
Issued: Wed 16 Oct 2013 22:50
Forecaster: GATZEN
A level 2 was issued for southern Turkey mainly for excessive precipitation and to a lesser extend tornadoes.
A level 1 was issued for western Turkey and parts of the Aegean mainly for severe wind gusts.
SYNOPSIS
At the edge o low geopotential across estern Europe, the intense cut-off low finally digs south-eastward and is expected across Turkey on Friday morning. A very strong mid-level jet streak will spread across Greece and the east Mediterranean in the wake of this cut-off, providing strong DCVA. Moist low-level air ahead of the cut-off will be the focus of convective activity. Weak lapse rates and/or dry low-level air limits the convective potential over most of the continent, though.
DISCUSSION
Southern Turkey and Aegean
Strong QG DCVA is forecast ahead of the approaching cut-off low that crosses southern Turkey at the end of the period. A low-level southerly jet will be in place on Thursday morning and advects a moist boundary-layer onshore. Latest GFS indicates a mixing ratio around 10 g/kg. Given moist adiabatic to slightly unstable lapse rates, some CAPE is expected. Onshore, upslope flow, strong DCVA, and convergence along and ahead of the cold front with easterly surface winds are expected to be associated with deep lift. Widespread precipitation with embedded thunderstorms, likely an MCS, is forecast to move east in th morning hours.
With favourable veering profiles ahead of the cold front, embedded mesocyclones are possible, capable of producing tornadoes. Together with the cold front, the tornado potential spreads east during the day. The main threat will be excessive precipitation due to the front-parallel low-level flow and the chance of back-building convection.
In the wake of the cold front, more showers and thunderstorms are forecast across the Aegean and Turkey. Weaker vertical wind shear limits severe potential, although a few severe wind gusts are not ruled out due to the strong northerly flow in the wake of the cut-off low.
